9 replies to this topic

[MadeInJapan]

I posted this on MVS but still have persistent problems...maybe someone here can help. I'm including the dialogue there in its entirety. Title says Throttle Position- I meant to say TPS (throttle position sensor). Oh and this is on a '94 non-turbo 850 w/ EGR and 190+ miles..just acquired a few months ago.

Me: I had done a PCV replacement but used an aftermarket intake manifold gasket which leaked and therefore changed it out with an OEM gasket, essentially doing most of the PCV replacement over again. After getting the new intake manifold gasket back on the car and things running much better, initially the check engine light went out on its own- now it's back on with a vengeance. Could be that all of the air leak earlier from a bad gasket caused this, but now I'm getting a 2-1-3 code on socket A-1 (transmission) that translates to Throttle position (TPS) signal too high. Has anyone had this? Is it the Bosch sensor attached to the side of the throttle body that has lost it's stuff and I need a new one or is it possibly something else? I try to clear the code but it won't clear. Any ideas, please. I want that damn CEL off!



Reply: I would try first to reset Ecu with disconnecting negative battery cable for about an hour or left it disconnected over night,and then try to clear the code.
Maybe the ecu has blocked itself,it happens sometime,just like normal(desktop,laptop)computers do.
I think that's worth a try.



Me: Already done that...it was disconnected all last night but no change...

Bought a known good used TPS (throttle position sensor) from a guy on V.S. We'll see how it goes after that's in.



Me: (3 days later) Update: Part came, installed it and reset code...turned off check engine light...started car- Same 2-1-3 code reappears and this time the flashing up arrow on the dash...ughhhhhh file:///C:/DOCUME%7E1/DAVIDE%7E1/LOCALS%7E1/Temp/msohtml1/01/clip_image001.gif



Reply: Disconnect the TPS and start the car. You should get a code for signal to low. If not, pull the plug on the computer, get the ohm meter out, and start checking the wire harness out. Ground circuits would be what I would be looking at first. My own 97' had a wire harness fault so it's not that uncommon.



Me: Thanks for your reply- maybe pulling on things to get the throttle body out of the way, etc. when I did the PCV system (intake manifold off twice- long story) could have damaged the wires. My son drove the car today and the good news it the flashing arrow is gone- check engine light persists. Another good things is I was able to turn off the the 2-1-3 code on A-1 (TPS signal too high) but still the check engine light is on- now I get 4-1-1 out of both A-2 and A-6. Code decipherer says TPS signal- that's it...so I'm stumped- wouldn't I get a "low" code from this if the TPS wiring is bad?



Reply: Mij, it feels like it is electrical file:///C:/DOCUME%7E1/DAVIDE%7E1/LOCALS%7E1/Temp/msohtml1/01/clip_image002.gif. I am sure that you have done the wire jiggle, cleaned the connections, checked for frayed wires and loose battery terminal connections and corrosion on the ground lugs. As a last thought, the age of the wires seem to be a problem in my car, the insulation has cracked due to heat and age, it may be that you have a short and this is causing your fault. Look in wire bundles, you alluded to the fact that you may have done some harm when tackling the manifold.
All being said, with your encyclopedic knowledge of Volvos, I know you will accept my humble suggestions in the manner they they have been profered.



Me: Thanks for your reply.. The fact of the matter is, I am a Volvo enthusiast but I still get a bit queezy when I tackle something I've not run up against for the fist time on these things- this is one of them. I became a moderator which forced me to learn more so I'm just learning like so many here- Ozark, Bill and now Vegas I believe know a whole lot more than I do about these cars. I'll check into the wire bundle again- it's just in such a location (the wires going to the connector on the TPS) that it's very hard to get any further along on it without taking a ton of things out of the way including the battery and battery tray, etc. When I get some time and my son isn't driving it, I'll to at it!



Me: (2 days later): upadate: Thought I would tackle this today once and for all...got under the hood and found the restricting valve under the master cylinder leaking so I tackled and hopefully fixed that...went in for the TPS again- hoping that I could figure it out... long story short, I decided to put the old one back in and see what happens. The bolts that tighten it one wouldn't come out- ended up stripping one out and so had to use a dremel tool to slot it...finally came out...old sensor reads 2-1-3 on A-1 as well as 4-1-1 on A2 and A5, so there's a signal Missing- tried to follow the wires from the TPS connector but it disappears into a loom and meets up with other looms, so that's where it stopped. Took all 3 computer out and sprayed the connectors with contact cleaner but this didn't change a thing- Check engine light is still on... I guess I'm going to have to test resistance on the connector itself- anyone know how to do this?

[MadeInJapan]

hate to bump this but Does No One Know????

[AlvinL]

Probably not a fault in the sensor but a short in the signal wiring. Look for that.

Quote

Diagnostic trouble code (DTC) information 2–1–3

Condition

The throttle position TP signal is passed from the TP sensor via the transmission control module TCM. The signal tells the TCM how far the throttle damper has opened. The TCM uses the signal in its control functions, among them controlling gear–shifting and the system pressure. The signal normally varies between approx. 0.5 and approx. 4.2 V. Opening the throttle damper increases the signal voltage. If the TCM registers a signal above 4.8 V, DTC 2–1–3 is set.

Substitute value
Control Module GROUP I:
The transmission control module (TCM) "Emergency mode" program is initiated.
Control Module GROUP II:
The transmission control module (TCM) "Emergency mode I" program is initiated.

Possible source

-Short circuit to battery voltage in the signal wiring.
-Fault throttle position sensor circuit.

Fault symptom[s]
-Rough gear shifting due to maximum system pressure in the transmission
-No Lock–Up operational.
-Gear–shifting operation can change – irregular shifting.

[MadeInJapan]

Yes, right...I know that- it's just that the wiring disappears into loom after loom- what's visible I can tell is fine-
I hate to cut up all those looms- was hoping someone had experienced this and knew what to do.

[cn90]

During the PCV job, there is alot of tension on the throttle cable (if it is not removed). So make sure the throttle cable is properly adjusted.
Turn the TPS, you should hear a click.
At idle, it should be in the idle position.

[MadeInJapan]

Thanks!
Do you turn it on the car or off the car- I'm assuming you turn the inside portion that has a slotted plastic piece that is white.
Your information is very helpful...

[AlvinL]

I think you have the wiring diagram. If it is a short somewhere, bypass the harness between the ECU to the sensor. There are three wires to the sensor. Do it for one wire at a time until you find the culprit. It will mean you have to cut each wire going into ECU or terminating point(s) and at the TPS sensor to replace with your own.

That's what I would do.

[MadeInJapan]

I've looked and do not have the wiring diagram for the TPS (I'm horrible at reading these things anyway)...any help would be appreciated.

[MadeInJapan]

Well, on a fluke I tried to reset all of the codes again this evening and every one of them reset!
We'll see how long this lasts- the car drives fine otherwise so it was hard for me to believe that this was a real problem- we'll see.

[misa]

Glad you solved it!