Funky TPS issue

Ok so i got a TPS code 24 on my '96 2.5L. I went through and checked everything and it seems in spec.

on my TPS i have 1 3prong connection.
A-gound 3.3 ohms to firewall
B-return range of .69v closed throttle to 3.82 WOT
c-supply 5.14

seems all good to me. i dont understand it. I know something has to be up cause everyonce in a while it stumbles hard when i gas it. once it warms up it is gone. Do i need a new TPS?

might be fuel issue...try changing the filter. Have you checked the plugs and made sure the boots are on properly?

Jess said:

might be fuel issue...try changing the filter. Have you checked the plugs and made sure the boots are on properly?

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fuel filter was changed 10k miles ago, plugs and boots were done 25k ago. i am still not sure how that would cause a issue with the tps sensor.

no impact on tps code...just symptoms you described.

Does the voltage change smoothly between the high and low values? Often there is a bad spot in the middle of the range.

lawsoncl said:

Does the voltage change smoothly between the high and low values? Often there is a bad spot in the middle of the range.

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didnt check well on that i will go back tomarrow....

According to my notes on the 1987 TPS, B is the ground, and A is the +5 volt supply with the throttle closed. Sounds like yours is connected backwards unless they reversed them in later year models???

I just discovered that mine was connected backwards on both my TPS and O2 sensor. Reversing the connectors so that A-A are connected to each other and likewise B-B and C-C, instead of A-C and C-A, fixed most of my problems. Seems these conectors can be connected backwards.

Mike McGinness
South Houston, Tx

Ecomike said:

According to my notes on the 1987 TPS, B is the ground, and A is the +5 volt supply with the throttle closed. Sounds like yours is connected backwards unless they reversed them in later year models???

I just discovered that mine was connected backwards on both my TPS and O2 sensor. Reversing the connectors so that A-A are connected to each other and likewise B-B and C-C, instead of A-C and C-A, fixed most of my problems. Seems these conectors can be connected backwards.

Mike McGinness
South Houston, Tx

Click to expand...

I came up with the same when i searched for the connetions, but all i could find was for the 4.0 so maybe its different. not sure. what do you have? can anyone else confirm this before i go swapping this around?

Just check the A-B-C code on the wire end of each end of the connectors and make sure that A is connected to A and that C connected to C, B is the middle wire and is always connected to B. I disconnectd mine and tested the ECU wiring connector itself for 5 volts and for the ground with the ignition on to make it easier to test and to isolate parts. Then I ran an ohm meter test on the TPS itself as I moved the throttle back and forth. It just makes better sense to me to test them seperately. The TPS is just a fancy variable resistor. It should read a smooth steady change in resistance from high to low, or low to high with no flat spots or swings as you move the throttle. Flat spots or swings in resistance as you move the throttle would indicate a bad spot on the TPS.

Mike McGinness
South Houston, TX

Mine is a 4.0 liter.

Mike McGinness
South Houston, Texas

Per 1996 FSM...

"The TPS can be tested with a digital voltmeter. The centre terminal of the TPS is the output terminal.
"With the ignition key in the ON position, check the PTS output voltage at the centre terminal wire of the connector. Check this at idle (throttle plate closed) and at wide open throttle (WOT.) At idle, TPS output voltage must be greater than .2VDC (200mV.) At WOT, TPS output voltage must be less than 4.8VDC. The output voltage should increase gradually as the throttle plate is slowly opened from idle to WOT."

NOTE - If you're going to check TPS function, there are a couple of small things to keep in mind...

1) The sensor must be connected. This means backprobe pins or piercing the harness insulation. I've successfully used both straight pins and straightened paper clips for backprobe pins.

2) You're checking a variable voltage, and most digital voltmeters/multimeters (DVM/DMM) have inbuilt buffer circuits - which means that respons will lag a bit - and be jumpy. This is one of those tests where you're better off having an analogue ("sweep") multimeter/voltmeter, since there're no buffer circuits, and you'll see the response more clearly. "Flat Spots" typically happen at cruise RPM, or "part-throttle," so run very slowly. You need not have the engine running - but you DO need to have the key turned ON for this to work.

PINOUT -
Terminal 1 (VIO/WHT) is the +5VDC supply to the TPS from PCM pin A17
Terminal 2 (ORG/DkBLU) is the TPS signal to PCM pin A23
Terminal 3 (BLK/LtBLU) is the TPS ground to the main sensor ground. This is spliced into the ground near the fuel rail, between injectors #3 and #4.

Terminal 2 (ORG/DkBLU) also gets spliced into the TCU pin D2, for automatics.

Looking into the harness connector from the "pin" end with the retaining latch held UP, the pins are 1 through 3 going from RIGHT to LEFT. Looking in from the "wire" end, therefore, they'll be 1 through 3 going from LEFT to RIGHT.

Again, an analogue ("sweep needle") voltmeter is preferred for this test, as it will give a more accurate and effective picture of TPS function and a smoother display.

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'87 is Renix, '96 is Chrysler, they may not be the same. '93 on 2.5 and 4.0 will be wired the same.

aardvark4x4 said:

'87 is Renix, '96 is Chrysler, they may not be the same. '93 on 2.5 and 4.0 will be wired the same.

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Ayuh - that's why I pulled my 1996 FSM off the shelf - they damn sure are different!

Recall - the RENIX system was actually designed by Renault and Bendix under the direction of AMC, and the system was built by Bendix/King under contract to Renault. I believe it's a revision of the old "FENIX" system found on some Volvos of the time.

The ChryCo system works different all around. There's a good reason I'm collecting FSMs...

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