Which Throttle Position Sensor?

[aliciaford]

So, my 94 Q45 has been having some issues when traveling uphill or at a higher altitude. It almost seems like its starving for fuel, but Ive done the fuel pump, new fuel lines, and new filter and everthing seems fine. However, the TCS and SLIP lights are on again and have stayed on and the TCS is non functional. I take it to my local guy and he says the code is for the Throttle Position Sensor, but cant tell which one and needs to do further testing. Ummm...thanks. Is there a simple way to tell which is causing the issue? Im having a hard time downloading the FSM. Thanks

[240RB1]

If you stand at the front of the car facing the engine the one closest to you is the tps sensor for the traction control.the on closest to the firewall determines air volume and shift points for the transmission

[ericthered]

I just replaced my Secondary TPS on my 94 q45t... I think it was code 13 on the controller module in the center of the dash. The secondary TPS is used only for TCS... do you mean the secondary TPS?

Also, the secondary TPS is the nearest component to the top of the front driver's side strut.

I pulled the connector off the TPS and tested resistance on it, it was not per the spec in the FSM
(FSM has a very specific test stated). And I used the ohm meter to figure out how to psotion the replacement part.

[aliciaford]

Eric, did you have other issues with the cars idle or anything besides the TCS lights? Im thinking if the secondary TPS sensor is bad and it doesnt have anything to do with the air/fuel then I may have other issues.

[ericthered]

The secondary TPS has nothing to do with idle, etc.
It only is used once it is indicated that traction control needs to reduce torque to a slipping wheel.
And it only is used in some special corner cases. - but it does cause the TCS and SLIP lights t come on if it is broken.

The error codes for TCS caome from the TCU in the trunk.
That error code can indicate a TCM problem, and then you look at the error code on the TCM in the dash... which for the secondary TPS us 13 (if I recollect correctly).
NONE of this affects your idle.

So you likely have other issues.
The ECU also throws error codes, but a bad idle likely does not.
You are then into the standard how to fic my idle/engine smoothness troubleshooting.

The usual subjects are the MAF, AIC, Injectors, and a few other things.
I think www.q45.org might be the easiest place to look for the standard problems to look for.
I think there was a thread on this subject about a month ago, too.

[aliciaford]

Thanks Eric. Thats what I suspected, but just wanted to verify. As far as I can tell, its a 13 code, so I will replace the secondary TPS and go from there. Weve already cleaned the throttle body and it has a new MAF and the injectors all checked out ok. Hmmm...more reading. Thanks for your help.

[LoxMurda]

I had the TCS SLIP light issue twice before. Check the TCS & TCM for codes. TCS in the truck and TCM under the dash next to steering column. Use a cell phone to record the flashes to save your some time. Your eyes might decieve you, then refer to FSM. TCS almost always guaranteed to to be blinking 13 times. TCM pulses will help narrow down the issue. Once I had code 13 on the TCS (secondary throttle signal was open or throttle curicuit open or TCM in fail safe mode) and code 22 on TCM (throttle motor circuit (short check)). Sure with the hood open I could hear a clacking sound from the throttle motor, replaced to with a used one and all was fine. About a year later TCS & slip lights came one. They would light up it seemed every time i hit a bump or took a corner to hard. I had code 13 on the TCS and 21 the TCM (throttle actuator (throttle motor circuit open). I change out both blue relays under the battery, now the lights came up right ater I started the car. (WTF). I decieded to do wiring check for later, I had to replace my valve cover gaskets. I sprayed and cleaned all connectors. After replacing the gaskets, I haven't seen the Slip and TCS lights come on. Now the Slip lights up like it should when the wheels slip. It's been over a month now. (knock on wood)