DngrZne

Of course the car decided to do this 45 minutes from home, although it's better than the 150 miles away I was yesterday. It's a 98. The story is I was driving to school today and it snowed/rained last night so the roads are a slushy/salty mess. I made it about 14 miles, went over a small speed bump and all of the sudden check engine light and reduced power/service traction control.

I was able to get into a parking lot right there where I could watch a bit more closely and found out the car won't idle and stalls without revving the engine. I let the car sit about an hour and it seemed ok, so I figured I would head the rest of the way to school. About 2 minutes later it started up again, but I was able to limp the rest of the way, revving and occasionally restarting the engine.

From doing some reading I have found it could be either a bad TPS, bad TAC module or dirty/wet connections. Is there any way I can narrow it down better than this? Unfortunately I have somewhat limited tools here, and until I can attempt to get the car 16 miles home will be somewhat limited to what I am able to do.

Is it possible to get to the TAC module through the battery compartment without removing the inner wheel well? I'd like to see that the plug isn't wet or corroded. I'm not sure I will be able to get it open without jacking up the car otherwise, which I can't do here too easily.

Also, are there any grounds specifically related to those systems I should be checking and if so what would the location be?

Thanks in advance,
Chris

lucky131969

Can you see it...yes. Can you access/inspect the connector....no. That access panel needs to come off. Do the simple inspection first, of the wiring to the throttle body/TPS sensor, etc.

DngrZne

Ok, thanks. I'll start at the top and work my way down. From what I could see the TPS wires are dry and relatively clean. Of course my TPS is held on with the old security torx bits as well so I can't pull that apart too easily to check the sensor surfaces. I will check the grounds behind the headlights as well. Worst case I will have to just try to turn the wheel hard one direction and see if I can get that panel out. The wet and salty roads really make me think a bad connection is the culprit. Otherwise I will be trying to locate a new TPS and a new TAC module after limping the car home revving the whole way to keep it from stalling, haha.

dougbfresh

Pull the codes, bet you have a few.

tblu92

Sounds like the "bump" you drove over caused it to go into limp mode the 1st time---This happens to mine often easpcially when going over railroad tracks----The TAC and TPS codes could be a result of the wheel speed sensors losing contact after the bump---The traction control and the ABS brake system uses the same data from the wheel speed sensors--The tract control to keep the wheels from spinning and the ABS to keep the wheels from skidding ( under hard braking) To achieve control the ECM uses the throttle position to control or limit TQ---So a TPS TAC code may be a result of a foul with the wheel speed sensors---check the pigtails at each wheel--they get dirty from moisture,dirt or unplugged from bumps-
and the codes you list are simply a byproduct of a wheel sensor fault
Another issue associated with a TAC/TPS code is code P1514---This code is caused by something else---It also will limp the car-- This will set if the "predicted TPS airflow "is out of range --this can be corrected by adding like 25 % to the entire predicted airflow table
( EFILIVE table C6101)

PS: turning the key on/off 3 times will reset the limp mode temporarily in either case to get you home----

DngrZne

My buddy brought me some tools and a flashlight and we pulled apart the TAC plug and greased it, as well as the TPS plug and we removed the big ground junction block, pulled it apart and cleaned it, greased the pins and were able to get the car back here without any more issues. I will take everything apart and do a better job now that it is home again though. Thanks again for all the help everyone!

lucky131969

Dielectric grease is not appropriate for the connector pins, as it is an insulator. I would get that cleaned up. Nothing is better than metal to metal contact, between a pin and socket.