The Throttle Position Sensor, or TPS testing  (theory)                                
and  TPS idle switch Calibration, U.S.A:         See the cal. matrix ?     Jump to index.

(jump to 1.8L J18 SPORT ENGINE  is set to 0.5v   or J20 engine has no idle switch at all)                         
There are 3 bench tests here (video's).
This page assumes ,  no bad associated things wrong!
The TPS cal on the G16 is tedious, at best. 
My list of symptoms are here:

The G16a/b TPS, has 2 parts,  It is Ganged !   1 POT. and 1 Switch inside.
On/off  car TPS sensor tests, to follow:  
ON means the switch is closed (very low ohms ,typ. about 50 ohms) OFF means the switch reads, Infinity. ( resistance meter)
Side 1, Idle Switch.   (this switch never produces 0 ohms, but does go below 300 ohms for closed , ECU expects less that 500 or less)
Side 2 , the Pot. side called TP pin, is the Throttle angle pin,  and allows for the ECU to enrich fuel with a fast right foot. (and many other functions related to this pin)
The Throttle angle pot is a crude 5,000 ohm Pot. or potentiometer, or variable resistor. It is a passive device, no electonics in side, only carbon . Is never calibrated.

Buzz words:
CCW = counter clock wise ,  CW , guess?
W.O.T = Wide Open Throttle.  (over 75 % is WOT most cars)
TPS = Throttle Position sensor,  or TP and Throttle Position  , on newer cars 96+ it is called a Throttle angle sensor.
Pot = Potentiometer, or variable resistor. Pot for short !, The TP pin is the Pot  wiper pin.
TP pin is the Throttle angle pin (wiper) of the TPS, not the idle switch.  An electronics guy, calls this the wiper pin, that is because it wipes the carbon, as it moves and picks off a new resistance.
Glitching =  This means that each side, must move and be linear, in action, the POT wiper must not ever glitch to higher ohms , instantly as you move the TPS lever.
The idle switch must be linear from say 50 ohms to 300 Ohms,  (what ever your ranges is , it must be Linear in that range, not glitching open , in that range of closed) NO BOUNCING !
The idle switch will be near 300 to 500 ohms when it goes totally open ,this is normal and is not a glitch. It's just a carbon switch.
TV = throttle valve, that is the butterfly valve dead center in the TB ,the Throttle body.
PO =  Previous owners,  (mostly with no books or tools)
M/T = Manual transmission,  A/T  , yes, automatic  (this is all ASE /SAE jargon.

The TP Pot side of this sensor is never calibrated (1.6L) we only calibrate the Idle switch .(the TP pin side, gets a free ride)
The 1.8L, this changed to no switch at all, and super easy setups.
1.8L DOHC motor, is calibrated with a volt meter to 0.5vdc at idle.   no Feeler guages needed on the 1.8L or 2.0L  J18/20

Below, I cover both the  8v and 16valve engines. 
I will cover testing it and calibrating the idle switch ( if this switch side fails there will be no idle regulation, the ISC goes dead.)
Best practice, is to test this sensor, first then calibrate it.  (testing off car and on a bench, for glitching and non linear action, is a big help)
Guessing and throwing parts will cost over $200 for this part.
The   FSM instructions, are side linked here, so you can see for your self .
The Dash pot, has spring inside, and pushes outward that plunger by default, and holds the throttle open with keys in pocket.
Thus the need to retract it , to do tests and calibration of the TPS.




INDEX:  To TPS checks and Calibration all 10 years. In each case, real factory FSM books are shown or offered as links.
My meter, I can't figure out  how to use my DDM  meter.
We must first discount, some the crazy owners reasons to mess up the TV or TPS indexing:  TV means Throttle valve.
PO means the Previous Owner(s).
Never allow the PO to fiddle this idle stop screw from 1991 to today.  If they DID?, here is the easy fix for  the stop screw.


INDEX:
Early 1989-90 8v TBI , TPS  Calibration and testing  (it has no idle bleed screw, yikes !)

Late  1991+  8v TBI and newer TPS testing .

Last 1991+ 8v TBI , and newer  TPS  Calibraion procedures.

TBI idle switch test. (volts check)

16v TPS testing only. (92-98')

16v TPS Calbration only.(92-98')
                  
The multi-engine Feeler gage  matrix Chart:

How do TPS fail? (lots of ways)


 CALIBRATION GAGES : 10 years of methods and values.
Go, & Nogo feeler guage chart:  Suzuki in black ( with GM deviances)  USA FACTS !
The 8v is a TBI , throttle body injection
a.k.a. SPI Single point injection, by some. ( except some 1.3L Carb. cars sold only, in USA 1989, if true, hit back button)
The 89/90' TBI is a very hard car to adjust, because the Idle adjust , changed at ANY time, wrecks the TPS calibration(corrected in 1991, this folly)
MPI 92 -98' 1.6L only USA.  MPI is 16v Multipoint Injection motors.  
 
This table was made from real USA FSM data.
WARNING: THE DASHPOT DEVICE MUST BE RETACTED for all on car checks below (only 8v TBI, has that)
(tie it back, suck it back or remove it.)  (suck means, use  vacuum hand pump tool)
All tests are done keys in pocket. Key off.
The Feeler gauge Matrix Table 1: 
(the red numbers below , are odd GM /GEO numbers, I ignore them) All sizes are in inches (imperial USA inches) times 25.4 for mm.

Engine
1.3L TBI
1989 (rare)
1.6L TBI 91 to 95'
1.6L MPI
92 to 98'
1.8L Sport
DOHC
89-90
TBI
Ohms
CALib.
.012
.016
.026
0.5Volts
note1
Threshold
NOGO
.016
0.20  (.035)
.037 (.031) N.A.
none
Infinity
GO
.008
.012
.020
N.A.
 none
closed.

Closed means less than 300 ohms. (is goal , 500 is law , spec)
Open = infinity, (meter shows , infinity ohms)
Threshold is setting it, just so the switch has just closed.
If you removed the TPS and didn't index the body TPS pins to the TPS actual pin sockets, none of this will work correctly. You may cause the throttle to stick open.(a danger)
Keep in mind, when you set the .016" setting (example) you then remove the feeler , and the throttle retracts .016" and you get a solid repeatable less than 300 ohms each time.

GO = Closed IDLE  switch  ( less then 300 ohms)   (300 ohms is TPS spec, , ECU spec,  i think is 500) I use 300 ohms.
This is no gold contact switch, it's only CARBON!   It will never read zero ohms, like real gold contact switches would.
Infinity resistance ohm, is open = ( meter DMM displaying O.R, over range, or  O.L, over load, see your meters operational manual, some show overrange in different ways)

NOGO= Open Switch.  (Infinity)  
If your meter is a fixed range meter not auto ranging then ,use the 2000 or 2k ohm range.  (if the autoranger shows 2.01 K that means near  2000 ohms, K means times 1000.
if the Autoranger shows 0.300 k that is 300 ohms.  see?  the K shows up on the LCD display , or omega sign or M for million. (your meter manual shows these facts)
CAL = Only the  IDLE switch side is calibrated ! and CAL means you get the switch to just close, and you  stop turning the TPS body. aka, set at threshold of closure.

The switch side is a bit strange, let me explain. 
The Switch side Low ,will vary from about 20 ohms (50 ohms is par) to 300 ohms  closed (experience) and then go to open circuit, very soon ,as you crack the throttle open just slightly.
In most cases 30 ohms to 500 is the range on the switch carbon then jumps to INFINITY,  The only reason this is hard, is the silly carbon cheap suzuki switch.

The reason 3 gauges (feeler) are used is to compensate for human errors setting this switch.  (non 89-91)
If you get this wrong , the engine RPM , may  surge &  THROTTLE TIP-IN acceleration will hesitate ! ,due to, too late IDLE drop out or too early idle release,.

NOTE 1 Exceptions:  G16a   TBI  EFI  1989/90 ONLY  using these special  steps only.
ONE FEELER setting on older kicks.  (This car has no top air horn  Idle air bleed screw, is a top clue !!!)
1989-90 Note 1:  (old kicks use only 1 guage , FSM)
This car , this year, this TB, this calibraton, destroy's idle speed calibration. So be ready to do that 2nd.
THE CAL feeler gauge: choices:  M/T is 5sp manual transmission. A/T is automatic tranny
0.086" M/T     we say in the business 86 Thou !  (yes , stack the feeler gages)
0.094" A/T (nearly a 1/10 inch !) huge. huh?
Rotate TPS fully clock wise, then CCW gradually until C to D switch JUST closes.
There are  no , GO or  NOGO gage tests, for these 2 early years. So calibration can be harder.
The DP must be retracted.
Yes, setting up 94 thou , is a pain,  no feeler gage set has this size.  I had to stack some feelers to get this.


BEGIN TESTING 1991+: (8 valve  8V , motor only)  The 3 video tests (mp4)
See 1989/90 here.
This section is NOT CALIBRATION !   Check the hard fails first.

Do the 4 TPS tests below first, or the Calibration steps here, can FAIL.

Many shops just guess and pop you with $250 + labor.
Some shops,  $500 for the TPS and then labor,  High way robbery , huh?




There are 2 tests, to try, pick one?, ohms or volts. ( Volts is best, as that is Rubber Meets the Road !)
Even better is a scope on pin, B then C, testing both for glitches, a TPS when worn, loves to GLITCH !
A Live on car voltage test:  
See figure 1 above, for pin Identifcations. (I will use harness side colors, because they do not change)
Do not disconnect  the connector, until you wish to do an OHMS test.
VOLTS TESTING:  using any needle or backprobe meter lead set.


Key ON:  No start (we will measure, the 4 pins live and hot, and use back-probling method) All connections, normal, no disconnects!
A $10 Walmart meter  DMM or even analog  meter ,even works here.
Setup 1:
Set the DMM voltmeter to 20VDC range, and connect the minus (black) test lead to the battery, minus lug ,for best results. (or to the engines shinny metal) For a ground reference.

Backprobe the TPS connector, using the needle on the red meter test lead.
These simple tests follow below: The Dash Pot must be retracted , when stated.
Test 1: Pin "A", power pin test.
(+5 vdc is applied to the TPS pot pin "A", if not , ECU is bad or this pin "A" wire is grounded out..)  (mine reads, 4.7v and is good)
Test 2: Pin "D", the ground pin test,  it must read 0 volts , zero volts  0 to 0.5v .  if not the ground is bad. (This cut wire,etc)

OK, the TPS now has power !
Test 3: Pin "B" is throttle angle, or  a.k.a. the TP pin. for throttle pin.
  (if  this pin fails?, hard, the ECU may go to Failsafe mode, if it only glitches (bad) the engine power hesitates when you accelerate.
No voltage Jumpiness or drop outs allowed!
Pin B (TP pin) below,  the voltage will very,  for near 0v to near 5v, as the throttle is advanced.   The Advance must be smooth.
 if this pin drops below 4% throttle angle (below about 0.2Volts) driving, you will get DTC codes 21/22 errors. (I'm not sure which one is which)
The voltage will rise to at least 4v (5.2v max) as you advance the throttle, it must be smooth and linear, with no glitching , if it glitches, the engine power will hesitate.
Pin B (TP)   (see FSM here) ( the normal voltage idling is 0.6 to 1.5v
Pin B must not be stuck at 0v. it must not be stuck at 5volts.  Stuck at 0v means  Pin A  wire is cut or open or ECU pin A not at 5vdc,
Pin B stuck at 5v, is caused by a bad TPS or the ground wire broken.  Pin D  is Cut or the TPS is bad.  (cut means broken,cut or corroded)
Pin B, voltage must move, and  be directly proportional to your throttle actions !   ( as you  vary the throttle (with hand) voltage  must be linear and smooth at Pin B )
FYI:
The only true 100% accurate TPS throttle angle  test Pin B, is with a scope, all other ways , to see all glitches.!!! 
Any DMM's meter can be very slow reacting, and miss them.!

Test 4:  (the idle switch tests,  after getting DTC 44 and 45?,  (stuck low, or stuck high , respectively)
We now test the TPS switch PIN.  Pins C .   TBI idle switch test, live !
TPS is connected to its harness.
Keyon, NOT RUNNING test:
Dashpot must be retracted by hand, during  tests, any of 3 ways. (hand vacuum tool, tie it  back, or removed (hard to do).
Connect volt meter  just like above at setup1.
Backprobe pin C. (at factory side, blue-white wire, ) This is the calibrate pin, and we are only testing now, not Calibrating yet.
If the idle switch fails, the ECU will not allow idle speed controls. (on other features keyed off this line, EGR enable, and many others)
The ECU can even hunt / surge (wild RPM changes) at idle if this PIN C is not working or set wrong.
If it stays closed too long, the ECU will fight you, as you tip in the throttle , one of the most odd sensations in car, you will ever experience, here)
Begin tests:
I probe pin C ,key On no start,, and  the dashpot is holding the throttle open now, (if not fix that now) and the voltage is 5vdc, ( 0.5v)
I then drop the DASH pot, arm and the throttle opens and the PIN C goes to  near 0volts, (closed switch ) 
You will not get perfect zero volts, just very close.
end test 4:


Predicates:
A bad idle switch makes calibration , impossible. (if it can't ever close)
In side the TB , Throttle body is a Throttle Valve, TV.
 EG: any of 3 throttle cables set tight, TV,cruise and A/T kick down cables (set wrong)

The TPS must never interfere with the TV. The TPS must not prevent the TV from closing 100%.            ( the "TV" is the Throttle valve.)
The cables must never be tight and holding the Throttle valve open (TV) at all.
Only the Dashpot on top left of TB throttle body, is allowed to do this. (keyon or off , not started)
The TPS can be mounted wrong, and blocks the TV  open.
end on car tests.


BENCH TESTS?: (off car tests)
The TPS can be tested on a bench too. 
By using  power supply and a 470k ohm resistor from the TP pin to ground.  (use a 6v, 9v or 12vdc battery as your supply  )
You can even do so with a scope to see if the TPS glitches,  It can be near tested 100% with proper tools.
Connect 5-12v to from pin  A do D.  (pin A is plus pin)
Then put load resistor 470k on Pin B to ground, (resistor side one at B other end to ground)
Test pin B (for linearity while turning the shaft inside)
Then move the resistor to pin C to  and the resistor other end to A(a pull up this is called.)


Warning, if the TPS delays opening, the idle switch , as you move the throttle pedal, a tiny bit ( .020") The ECU and ISC will fight you hard, and it will SURGE during that fight. A Very dangerous car to drive ! This  occurs because the ISC servo action was not canceled, at throttle tip-in.  Very bad that.
Normally what happens, at ECU pin A14,   it is at 0v at idle, then the driver moves his foot .020" (as measured at TB TV valve)  and the idle controls are ended.
If not, all hell breaks loose with the driver (Max Surge)  This is why we use the all 3 feeler  gauges  for calibration.
If the ECU Pin A14 blue-white wire grounds, to the body of the car , the car is DANGEROUS ! ( Surge logger heads ! with driver) Seen and demonstrated on all 8v.)
Watch for DTC 45,   it may take driving far to see 45's . (around the block will do)

The TPS resistance, OHMS tests/ not calibration.  Use this same drawing Figure 1,  

key off.
Disconnect the connector, above
We are testing for a bad TP throttle angle pin here. Pin B.
We are looking for any GLITCHES.  (any no linear actions are glitches, and are all a bad worn TPS pot)
The POT is a variable resistor ,see that above, it is a passive device, no electronics at all.
In fact, it is just a carbon strip.
We will  look for opens on the bottom side to pin D and open to A side and and open on the wiper pin, B.
To test A to D use the 20,000 or 20k ohm range.   (this pot is very crude, and reads 5,000 ohm give or take a bunch.  3500 to 6500  ohms
Use the 2000 range test for test C to D. This pin is even more crude.   (about less than 500 ohms closed is good) (mine read 100)

How can the TPS fail?
1991 + 8V:  The OHMS test.
 A not running test, KEY OFF,  unplugged. See Figure # 1  

TPS Disconnected:  ( you can leave it bolted on , just unplug it)  Do not force any Suzuki locked connectors , press the lever and wiggle gently.
The TPS is  a very crude resistor , grossly crude , so do not look hard at actual OHMs readings,  (infinity is bad) So is glitching to infinity on B.

Test 1:   The POT END TO END TEST.  (almost never fails) (Pot means Potentiometer )
(can be done with dashpot retracted or not, but I do , retract it) (for good reason, the wiper can hide a crack in the lower carbon section. )
Set meter to 20,000 (20k) range. OHMS.  Resistance or Omega  symbol , position. Use autorange if that is what your meter must use.
With any resistance meter, measure pins A to D , this is called an "end to end" POT test.
It will read  3500 to 6500 Ohms  this reading tells you what to expect next,  lets pretend you read 4032 ohms. (its good and not Infinity,  that be bad)
Good !, not an open TPS,  do more tests.

Test 2: (The THROTTLE ANGLE PIN or TP pin)
The TP pin  Pot test:    see wiper? pin B, the wiper picks off new resistances as it moves.
Now connect meter to pins B and D .
Next you must retract the dash pot (8v only) with vacuum tool or by unbolting the Dash pot, or wire it back.

You must advance the throttle by hand to do this test.
The Pot. side PIN B, must read  near  zero to 2000 ohms at idle stop  position and 2000 to 6500 ohms as you approach wide open throttle .
In my example here, this test will vary from real low (pretend 1000 ohms to 4000 ohms)  It must be linear and not glitch as you move the TV.
Raise the throttle to see this and repeat it as you move the throttle very slowly to see any drop outs.
Now, very the throttle from idle to WOT (wide open throttle)  the resistance must very smoothly, if not the POT is NOISY or has worn spots (very common).
NO Glitch'ing ALLOWED here.
A noisy pot will make the ECU false enrich fuel mixture  (MPG low?) or hesitations driving,  that recover. (or the opposite, gross lean , accelerating)
This noise can cause a delayed power,  this is the primary usage for this pot for the ECU to detect your fast gas foot. (fast throttle angles, net fast power, called enrich mode.)
If you know carbs.  the TPS acts as a "high speed accelerator pump" the squirt of  fuel you see, inside a carb Air horn. Same deal with EFI ,only it's electronic.
See the next frame below , for idle switch test.
Test 3 is the idle switch. seen next..
The 8V factory TPS data page:

1991+ 8 Valve motors, continued, we are still testing , not caibrating yet.  See 1989/90 here.
Ohms test testing continued:
Key off, 
Disconnected TPS ! Unpugged.
DMM Meter set to 2000 or 2k Ohm range.

THE 8V TBI DASH POT MUST BE RETRACTED !

See the DP, removed here.
PINS  C > D test  (figure 1 )
DP retacted the idle switch must close.
The TPS- switch portion ,should be closed  (30-300 ohms TPS spec.) at idle       [ some books say 0-500 ohms, 500 is ECU software limit, I think]
When the throttle goes off idle stops the swith goes to infinity ohms resistance.
 
My 8v TPS switch reads 15-25 ohms at forced idle. (many others read 50 or 100)  less that 300 is a GO.

The below links are TPS calibration procedures for the 8 valve engine then last, the 16v.
Do not condemn the switch until it fails , off the car doing a resistance test.
If it fails  this test, then calibrate it on car. That is the next topic. If it cant be calibrated , it is bad. (or the TV and TPS are fighting each other mechanically)
End of TPS testing.

  1991'+ , 8V TBI TPS Calibration of   TPS idle switch side: C and D.     The 3 video tests (mp4)
(all years 8v)  (this procedure assumes the TPS is not bad and that it was installed correctly , Indexed )                                                                  SEE 16V  Calib. here. 
See 1989/90 procedures here.

Again, the 3 throttle cables (up to) must not be tight. they are set loose per the FSM.
The TPS on some cars can be removed and inserted wrong, effectively making the TPS DEAD. (not indexed per the FSM)
Any ohm meter works, here,  even the $10 Walmart meter, works  very well.  No need at all for expensive tools to do this very simple calibration.
If mine is not clear read the Actual FSM here.

Prelimary setup:  (have the 3 feeler gages in hand,  or stack  them,  only 1 feeler is needed to do just the CAL. (the others are for validation steps)

This method is called GO, NOGO and CAL. (a fool proof calibration)  All pins are seen in Figure 1 above.
  1. Ignition Key is OFF.
  2. Retract the DASH-POT device , by using a hand vacuum pump,  or wire ties, or unbolt it from the throttle body , ( I use vacuum)
  3. Loosen the TPS mount screws. a tad, so the TPS can move easy, and  rotate.  See photos, at end of this page.
  4. Insert the CAL feeler size gage into the throttle stop screw gap. (open throttle, to do that)  0.016".
  5. Disconnect the TPS main connector , this connector has 2 other pins, for the injector , please ignore the injector pins.
  6. Attach the DMM  ohm meter (resistance mode ) to pin C and D of TPS connector, set range to 2000 ohms scale on DMM. (or autoranged)
  7. Rotate TPS CW , see meter go to infinitiy.  FYI:  CW = clock wise.  CCW = counter clockwise.
  8. Rotate TPS CCW , very gently and get the TPS switch to close, just barely. 50-100 ohms is typical. (below 300 is TPS spec) {ECU wants below 500 ohms}
  9. If the TPS screw mount slots bottom out, here the TV valve shaft is bent or the valve stop screws were VIOLATED, the TV must close 99.9% down to .001" TV/bore gap.
  10. Lock down the TPS side screws. Cheers !, you are now calibrated. The next steps are an audit of your work.
  11. Do the NOGO step. (the inserted .020" gage opens (infinity)the  TPS failing this, will cause TIP-in throttle bogs , driving.
  12. Last is to insert the .012" GO gage,  the TPS is closed (< 300 ohms?). (NOGO and GO gage sizes)  (this will not fail , if the TPS is good) IF fails?, then TPS is bad, (has carbon gaps)
  13. Put back the Dash pot, as you found it. (un-do your defeat method, @ step #2)
  14. The TPS is now calibrated and validated.  (no Code 44s now !) code 44 means this switch is bad. on  pins C to D.
If this procedure is done  incorrectly,  you will get a dead ISC or  way late, throttle enrich mode, and temporary bogging. (hesitations)

If the TPS switch will never close  , even with the TPS completely removed from the TB, then the TPS  is bad. 
If it fails on TB and is good off body, , TPS was mounted WRONG !  it is must be indexed correctly ! The Throttle must not prevent the TPS from closing, and vis versa.

FSM TBI actual pages on calibration.   THE REAL DEAL !
Never adjust the painted or capped off, throttle stop screw , for any reason. it is a factory calibration for minimum air supply {tiny}.  (except 89/90 years)
Below are the actual FSM pages for TPS calibration:  TBI 1991 and UP.

8v Page1 with pin connections.

8v Page2 with feeler guage spec.

8v Page3 end.

End FSM 8v.


EARLY 1989 and 1990   TPS Calibration  and idle speed          
These 2 years, are very unique.
All steps here:
This is the 89/90 steps for TPS calibration and idle speed, these 2 years are unique.                


See other pre 89/90 uniquenesses here.





END all 8V TBI testing and Calibration.

16 valve 1.6L  MPI  TPS  CALIBRATION procedures.     The 3 video tests (mp4)
 not for 8v, see 8v here.
The 1996 to 1998 real FSM calibration procedures for TPS is   Here  and   Here.

Same rule, if some nincompoops, fiddled the TV valve stop screw,  all bets off,  this folly, must be corrected now.
The tests are really the same as the  8v
  • Different  pin numbers
  • No dash pot.  The 16v uses software for a Dashpot function.
  • Different  feeler gauges sizes 

The TPS must not be bad.


Factory TPS calibration procedure for the 16valve MPI  92-98 Sidekick or Trackers. <click with comments.

The 16v TPS has no pig tail connector like 8v has, but has  4 pins,  and pin 1 is on the bottom. as seen below.
FIGURE 2:  Below is terminal 1 to 3 test for the POT test.
As you can see pin 1 is the bottom pin.
The below is the photo for the OHMS test, but in fact this same drawing shows you what pins to test for the live voltage tests. (use the 8v rules for these test above)
16 valve MPI only. all years. 92-98
The on car live, key on, voltage test is here. You must leave the connector connected,and us a back probe  technique, to read the voltages.
Pin 1  Ground.    Gray/ yellow    0 Volts.
Pin 2   Idle switch out               Blue/white    (0v when at idle 5v off idle ) Some GM books show pin 1 as 5v, this IS WRONG.
Pin 3   TPS  TP pin wiper POT or TP throttle angle   Gray wire  output varies from .5v to about 3.5v  idle to WOT.
Pin 4   +5vdc from ECU.            Gray/red
All colors are harness colors.  GM and SUZUKI may use different colors on wires, but pin 1 is always down.


FYI:  TPS functions are all explained.


16V TP Calibration method (FSM steps expanded)   "CAL steps)
 The TPS mounts to the TB (throttle body) and the TV, the Throttle Valve.

Adjusting the TPS switch  (Throttle Position Sensor Switch)  It's just a variable carbon resistor inside, no magic or electronics, just carbon.
Also, the switch part is not a real gold zero ohm switch ,it too is carbon, reading about
300 or 50 ohms.
{ FSM is Factory Service Manual }
Pre-conditionals: 
TPS not bad ,so test it first (using volts above live or restance tests).

See chart above (table) for exact Go  , NOGO and CAL feeler gauges.

Tools:
A set of feeler gauges.  a $2 tool.
A set of test connector pins (female really makes this job easy,  I just remove them from old connectors laying around)

If  the TPS was removed and then put back on not indexed correctly, none of the below will work correctly.
(the TPS is mounted preloaded, if you do not mount the TPS correctly, it blocks open the throttle with horrible idle failure results and more.... )
Attach an Ohm meter (DVM set to ohms resistance starting on the  2k range "2000 ohms") per instructions. (auto ranged meters, works ok too)

Make darn sure the throttle plate is closed by looking at the throttle stop screw and noting that the TV bell crank is hitting the stop screw tip.!  True IDLE !!!
If it does not, then you have a mech. TB problem, correct that first, (a gunked up Throttle body? or below butterfly plate ? or too tight throttle cable)

Begin the calibration.  ( I will cover 92-98 1.6L 16valve MPI method here)  A GO /NOGO method this is called.  (factory methods)

Note the Gap when closed, the stop gap is 0.200 inches exactly, if some nincompoop didn't fiddle that (fix that first or TPS will never work right, nor the ISC work right.)  This screw has a BLOCK plate.
The TV valve must be closed near 100% (99.9%, I call it) The valve plate to bore, is about .0005 to .001" gap, the smallest of  gap and not touching ! (there is no spec here,  I'm just telling, you the facts)
 Really, the TV is 100% the gap is just to prevent the TV butterfly from jamming in the bore, that is the only purpose of the bore gap. 
  • The Ignition Key is turned off,.
  • TPS end Connector unplugged, do not force it. All conn. have lever locks,  and Suzuki don't sell connectors. (just harnesses, if lucky)
  • On my 1996 the top of the TB has this huge black beauty plastic cover blocking all linkage,; remove that first,.
  • Place or Insert ( a 0.026"  feeler guage betten the TV crankstop and stop screw head.  (Removing  the cable bracket seen below is a great idea. Just 2 nuts hold it)
  • Loosen TPS side screws, so they are only slightly tight.   See photo of off car CAL. 
  • Then rotate the TPS CCW, then rotate CW it until the TPS (pin1 and 2 ) just barely (at the threshold) go to Infinity on DMM ohms scale.  (Counter clock wise = CCW)
  • Tighten the TPS side mount  screws.
  • Remove Feeler gage, note the  Ohm meter (Resistance meter) shows continuity (less than 300 ohms) (ECU expects less than 500 ) (do not expect zero ohms!)
  • If the TPS screw mount slots bottom out, here the TV valve shaft is bent or the valve stop screws were VIOLATED, the TV must close 99.9% down to .001" TV bore gap.
  • Insert 0.037" feeler gage here (stacking the gages works great) NOGO step
  • The ohm meter now reads Infinity. ( not 300 or 50 ohms  or less,or some other value , but true infinity)
  • Now insert the 0.020 inch feeler guage. and the reading must show 300 ohms or less.  GO step  ( I get 50 ohms , usually, do not expect 0 ohms)
  • Tighten all TPS screws (a double check) and put back its connector.
  • if any of these steps fail. repeat them all.  (if it wont calibrate the TPS is bad or mounted wrong or the TV is not closed 100% or someone bent the TV shaft or the TPS is not indexed to the body right.)
To be sure,must guys just set it to .026" drive around the block and all is well.
This method guarantees some tiny fractions of inches ( of over/under-travel.)  See chart on top of this page.

If this calibration is done wrong the following may (will) result.
  1. A dead ISC, or one that is active when you accelerate say to 1000 RPM, 
  2. The engine  will never idle or will idle out (DIE) at stop signs, etc. Or RACE at high speed,  the IDLE will NOT regulate. and Fast idle commands(ECU) will never happen. (A/C fast idle)
  3. If not closed this idle switch, at idle the timing freeze jumper then fails to freeze timing , as desired, for spark timing, procedures.
  4. if set  (closed switch) to far into the TPS range, then the car , will have TIP-IN bogging. Too late TPS idle switch opening. The ISC will fight your right foot in a very strange way....
  5. My 96 Suzuki will surge above 1500 if the switch stays closed too far into cruise range.  
  6. When you cut the throttle and the TPS fails to close, the EGR cut will fai, as will the dashpot effect, anti neck snapping feature, of cut fuel mode.  
  7. The ECU now throws, DTC errors for the TPS.
  8.  There are many features and function in the ECU that trigger off this TPS switch, most or all will malfunction.
Real TB 16v:  1996 acutal.
 
Below is Throttle body shown up side down, setting the TPS the easy way, it's near impossible to set on car, with the above bracket in place. ( 2 nuts hold the braket on, only)
The 16v Calibration point below: 



end calib.


TESTING the 16V TPS. THE OHMS test. Unpugged (no power testing)   The 3 video tests (mp4)
(I recommend testing it before calibrating the sensor )
The TPS can fail  this way:
The Throttle Position pin , or TP
The TP pin,  A.K.A.  POT wiper pin or throttle angle pin : (Cold ciricut test)   
 
(POT side is never calibrated , only the switch side is calibrated on any of  the 1.6L)
 
(this side causes fast acceleration rich mode "power enhancement" and causes WOT (wide open throttle mode) and causes Unflood mode at crank time.
Key off
Connector unplugged at the TPS 16v:
DMM/DVM: meter set to 20k Ohm range:  See Figure 2 above for pin locations.
The pot side of this TPS pin  1(bottom) and pin 3 , varies from 300 ohms to 6500 ohms, as you move throttle from min to max.
If it does not run in this range or has glitches or has dead spots, it is bad.  A $217 Suzuki part,  (after market parts are $100 more) find a used one and pray.
It doesn't have to be accurate , just consistent and linear.  !!  Again, this  side , is never calibrated. !  Despite crazy Internet myths to the contrary and accuracy bull.)
The switch side and the pot side are GANGed..
Hot testing:
You can conduct  a key on voltage test , the same way as the 8v using the Gray wire (wiper) and check for smooth advancment of the voltage as you advance the throttle.

DOA:  Show and tell:  (when things go wrong, never hit your TPS, oops , damaged , I bought a spare like this.! )
The Below internals of my TPS, are cracked, car will never idle.  Look close and see cracks.
DO not open the TPS like I DID Below !, this is a destructive examination !  HACKED OPEN!  shows cracks , that can happen.
This TPS was stuck in UNFLOOD mode, car will never start. due to fuel cut at cranking time.
Click to zoom image.  Figure 3: 
This damage happed during and engine removal. GOT HIT !
It also shows you how the carbon works, the Gold wiper device is missing here.
This shows you why the switch part never hits 0 ohms, like a real switch, that is because this one is Carbon, not gold contacts.
My  broken TPS, internals, hacked open

Seeing the ceramic substrate and the carbon thin films , is very visual and clear what is going on inside.
This photo clearly shows the 2 devices inside, the unit. a switch (right) and the POT. on the left.
the 2 (not shown) wipers short the inner and outer rings as they wipe.
The TPS is infamous to go intermittant first, then fail hard.
IF the TP pin has glitches as you accelerate?  then the ECU causes a hesitation when you demand power. This is caused by worn carbon on the above rings, end of life.

1.8L DOHC engine (or 2.0L) Sport Suzuki TPS calibration on the throttle body. "TB".
(1.8L and bigger motors. have no SWITCH at all now, one just sets the volts and you are done) {0.5v at idle , key on)

  1.  All TB cables are loose. per the FSM, normal slack, they are never sit  tight (very dangerous if set tight.  The same for cruise option cable.
  2. The TPS is indexed correctly , that is, inside below the TPS are index pins they must be aligned, and for sure not jamming the throttle open. Remove it and check it.
  3. Make sure the throttle fully drops the butterfly and end crank against the stops, there is a screw there, that bottoms out, do not ever touch that screw.
  4. Key on, no need to start engine.
  5. Connect the DMM volt meter to ground , TB casing,  and the red lead to the TP pin, via back probing of the TPS connector .
  6. loosen the TPS  screws until just a tad loose.
  7. Adjust the TPS to 0.5v that is 1/2 volt, exactly 
  8. Lock down those TPS side screws.  You are done. Now the ECU will enter idle mode and activate the ISC system.

(Which pin is TP ?. well, one is ground , one is 5v, and TP is low volts) It's the gray wire, with no stripe.)


See Full PDF (8pages) factory CALIBRATION.




METER MADNESS:
Volt meter, Ohm meter (resistance) or DMM. even a $10 analog Walmart meter will work PEFECT here, no need to buy expensive tools to measure 5v and 300 ohms. Not at all.
   How to use the DMM is  here.


General Information on TPS:  (and facts and myth debunking) 
There are 2 sections in this device, the top section  is the Potentiometer (POT) or as some call it a variable resistor. A,B and D.  (1,2,3,4 on 16v)
So there are 2  tests and only 1 calibration.
Side one is called the IDLE SWITCH , the other side, is the TP (throttle position side or Throttle Angle), This side form a basic Potentiometer, (POT) or variable resistor.
The calibration is only conducted with the SWITCH SIDE.  C and D Pins.  (8v example)
Failure of Idle switch:
If the switch fails , the car will NEVER idle correctly ( it will vary with load on the engine) 
This switch is not a gold contact switch, it's just a carbon chunk,   It has only 2 readings. less than 500  ohm and infiinity.   Never expect zero when closed ,like most switches.
The Fast idle control  features will fail, the Cut fuel and EGR may fail. The ISC will be dead ! 
The late to open idle switch, will case Tip-in fuel mixing problems.  Tip-in as in your right foot tips in the throttle and engine hesitates a bit.
The POT side TP SIDE:
Myth 1:  No, the TP side does not set fuel injection rates, that is, the ohms (voltage) does not get scaled directly to injection quantity. But does in LIMPHOME.
The TP does get watched by the ECU, for rate of  TV action,  you move the throttle fast and the ECU sees that and goes to ENRICH mode, until the MAF/MAP catches up.
If you have a throttle hesitation problem then do the  range test or the POT and ohm meter (resistance meter) test.
If  POT TP wiper pin  B or 3(16v) (reads above +3.75vdc  ,when trying to start the car, the car will NEVER start.
The rule for WOT is "About" 75% and above Throttle angle is Unflood mode.  The TP usually has 4vdc output at 100% throttle. can be more..
Un-flood mode.   I mention this, because the ground can be broken to the TPS at pin D  (p4-16v)and the car will never start.  Unflood mode forever. CUTFUEL cranking.
The POT side, has 2 rules (besides that the actual accuracy is very crude, some pots are 3k and some are 6k ohms,  a crude device. 
1: The end to end ohms on your POT must be steady at all times. if it reads 4k is must, be so, at all times (that is how your's is and works)
2: As you measure the Pot wiper pin, to the other end ground  pin,  say  D or (16v pin 1)  the TP pin must vary from below 2k ohms to max what ever you read in line above.
The key here, is that the wiper pin must NEVER jump open (infinity) as you move the throttle.
This is very common , this failure of the TPS.  after 100k miles many  TPS can fail on any car, and depends, on utility, be that, city ,highway or mix,  when that happens.
It it rare for any TPS to last the life of the engine. (about 300k) 
This page is only complex because of the 10 years  covered and 2 engines and evolutions of the same.
Never ground out the +5vcd refr. pin on the TPS, or you will blow up the 8v ECU trace,  16v is better protected.
Never hot wire any ECU output pins, or you will damage these simple ECU's . (hot to battery Plus or ground)



TPS FAILS: (TPS , it's wires. or bad ECU 5vdc)  (the DTC code #  change for 96+ but the words and reasons don't)

TPS switch open,  LIMPHOME IS IN EFFECT car starts, no idle controls, at all , ISC will be dead. DTC 44  , and 45 ( 45 is stuck at ground , very rare this , is a   harness short)
Other pins open will throw over voltage DTCs for TPS. (or under of 5v is missing)
Open ground pin,  the TPS goes to 5v and ECU may give  warning and engine may not start and  DTC code 21
 (  over 3.5vdc on the TP pin can cause UNFLOOD mode and all injections stop, depends on ECU year and its software)
 (22 is stuck low)
The TP pin pin  can do that (22) and is a bad TPS. or open 5v  wire (like 5vdc is dead on the 5v pin of TPS, 5vdc gone is bad ECU )
The TPS can crack inside (see photo just above) or wear out inside and give totally random symptoms.
The ECU has a tendancy to not see TP glitches (debouncing logic) and will cause hesitations, when advancing the throttle.
If the TPS errors are bad enough and constant the ECU may go, to limphome mode  and car does start.  (it the ECU, mimics the  bad TPS and runs VERY BADLY)

Keep in mind a failing TPS may send voltages to the ECU that the ECU likes and believes and Unflood mode gets activated. (silently; no DTC)
One guy mis-indexed the TPS prongs to the matching prongs in the TB,  and he got Unflood mode.  (4vdc on TP pin) all injections cut.

WOT is about 3.5v or more at the TP pin ,  and cuts all fuel , cranking...




The 8V below: TPS calibration point. TPS is located on the other side of the throttle shaft.
f
The feeler guage goes here above , to set the TPS calibration.


See More Tools ?

 

The Nincompoop section , there are no limits to damage or people doing crazy things to cars, wrong parts,  or damaging them. (my short list, lol)

PO = Previous Owners.
  • Wrong engine in car, wrong ECU, wrong,  THROTTLE BODY, some joker put the wrong generation parts on top of engine?
  • The dash pot device on the TBI 8v must be retracted for all tests idle speed setting and calibration.
  • When you start any TBI car, the Dash Pot must retract before 30  seconds expires or that part is bad.  the Dash Pot VSV valve or the DP hose,etc.
  • The TPS wires, are cut or worse cut and spliced on backwards. (corroded connectors after 20 years, no !) Causing DTC errors like mad.
  • The TV was molested.  The throttle valve adjuster screw was messed with , 1991 and newer cars.  this is totally bad.
  • The TPS was calibrated with the DP active. (DP = dashpot on rear of 8v TB) TB means Throttle Body.
  • The TPS was calibrated, but not tested with all 3 feeler gages,  91'+
  • The TPS was mounted wrong and not indexing to the internal tabs , thus jamming the TV at idle and making TPS calibration , impossible.
  • The wrong factory part number TPS was installed.
  • The TPS is dead driving , because the ECU is in FAILSAFE mode, (TPS unplugged too, does that, besides others  (dead MAP/MAF/ECT/IAT, cause that.)
  • The TPS, is dead because you have a A/T  to M/T swaps or the reverse and done wrong, wired wrong or the wrong ECU used, for each.
  • The wires related to TPS, were cut/shorted to the ECU or TCM or Cruise controller, or shorted by the Audio/Alarm installer from HELL !  "TPS WIRES"
  • The engine has huge induction air leaks , making the TPS ECU monitor software report false TPS errors.    (ECU sees, idle switch closed and RPM is a 4000 RPM,  low plenum vacuum...?)
  • The ECU +5Vref   pin is stuck at 0v,  making the TPS uselsss, and DTC codes thrown. 
  • PO removed the TV throttle valve plate (brass) and filed it for some  inane reasons. (an abomination!) (seen this done to solve low idle issues, a sure sign of desperation)
  • None of the 3 throttle cables:   1-driver, 2-A/T kick down or 3-Cruise cables, interferening with the throttle valve.
  • These 3 cables must not be set tight, with dash pot retracted on 8v. The FSM shows them all set loose.
  • A Missing Dashpot on G16a engine. (will cause , engine that loves to flood) but does make calibration easy, sure.
  • Gunk under the throttle valve, in, under and around.
  • The TPS was calibrated using the wrong feeler guags, as seen on many store, rag books or on line.
  • The TPS was not set with the feeler gauge on the threshold of closure. It must not over or under travel.
  • The TPS switch is not closed at idle, for  any reasons.
  • The TPS fails to open , at the correct moment the ECU will be very vary unhappy as the idle controls fight your right foot. at throttle tip-in (evil effects here)
  • Not correcting DTC 21, 22, 44, 45 first. and others.



Symptoms,of TPS issues: 
  • DTC errors. The ECU is telling you there are TPS, TP or Idle switch errors.  see above links? or is in FAILSAFE. Failsafe mode, kills idle controls.
  • Engine idle controls dead,  the RPM don't hold at 800 plus or minus 50 RPM with all electrical accessories flipped on then off,  (blower/defrost?) or on A/T Tranny shifting from park to drive?
  • Engine idle speed hunts, this can be  a lean engine or the ISC can not get idle to 800 RPM, if it can't, for any reasons , it can and will HUNT, a.k.a: Surge.
  • You tip-in the throttle  gently at idle driving, and the engine fights you. (late idle switch opening? )Some call it a JUMP or hop, but is a very strange feeling. (PO guessed at above CALIB?)
  • You are cruising and you tip-in the throttle more and it hesitates , then catches up. This is a bad TPS TP signal. The TP pin carbon section inside, is worn as all do , eventually)
The TPS on this car is tricky to calibrate. The key to success is understanding the threashold issues during calibration.
The TPS idle switch must close every time you drop the throttle (to near 0v)
and
The TPS switch, must open at the "correct moment" or the ECU will be very confused !

The TPS usually can never causes stalling, the #1 cause of that bad act, is  EGR stuck open.



rev. 16  , 10-18-2013  (losts of edits)