1 slow 97

My car has been giving me this probably lately. Check engine light comes on, service traction control message comes on, and reduced engine power comes on and the car wont go more than 5mph. I checked the computer and its giving me P1518 code meaning PCM TO TAC module serial Data Circuit. Any idea what this means? I called my chevy tec and he said that code means the the TAC module on the PCM needs to be replaced. It's $120 part, before I replaced it just wanted to know if anyone knew any more about this problem. Thanks!

WestCoastCorvette

The TAC module is located under the battery tray by the PCM. Hopefully you didnt have a leaky battery. :sad: :sad: :sad:


[Modified by WCC PAUL, 2:57 PM 1/22/2004]

mfrnka

I have this issue on my '98 a couple times a year. I think I've tied it to periods of letting the car sit and/or high humidity. I was told there are three throttle position sensors in the "fly-by-wire" system. If at least two of them don't have the same reading, you'll get this code.

Stopping the car and restarting usually clears it up for me. I've started pumping the pedal 15 - 20 times on occasion, while the car is off, before starting, and it seems to have helped greatly.

Perhaps you just need to use the full pedal travel more often. :jester


[Modified by mfrnka, 3:59 PM 1/22/2004]

0vetteshop

:cheers:

REDUCED ENG. POW. MESSAGE ALONG W/ PARTIC. PWRTRAIN #87-65-16 - (03/24/1998)
SUBJECT: REDUCED ENGINE POWER MESSAGE ALONG WITH PARTICULAR POWERTRAIN TROUBLE CODES (INSTALL NEW TAC-MODULE IF STRATEGY IN SERVICE MANUAL FAILS)

MODELS: 1997-98 CHEVROLET CORVETTE WITH 5.7L V8 ENGINE (VIN G - RPO LS1)

CONDITION #1: INTERMITTENT REDUCED ENGINE POWER EVENT, ACCOMPANIED BY P-1516, OR P1518 TROUBLE CODES.

IF A SITUATION ARISES WHERE A P-1516 TROUBLE CODE IS ACCOMPANIED BY A

P-1120 AND/OR P-1220 TROUBLE CODE, THIS SERVICE BULLETIN DOES NOT ----------------------------------------------------------------- APPLY. IN THESE CASES THE TECHNICIAN MUST USE THE NORMAL STRATEGY ------------------------------------------------------------------ BASED DIAGNOSTIC. -----------------

CONDITION #2: INTERMITTENT REDUCED ENGINE POWER ACCOMPANIED BY TROUBLE CODE P-1125 AND ANY OF THE FOLLOWING TROUBLE CODES:

P-1276 P-1281 P-1286

CAUSE:

CONDITION MAY BE DUE TO DIAGNOSTIC SOFTWARE AND CALIBRATION IN THE TAC-MODULE WERE NOT OPTIMALLY UTILIZED.

CORRECTION:

IF THE ABOVE CONDITIONS CANNOT BE CORRECTED USING THE NORMAL STRATEGY BASED DIAGNOSTICS LISTED IN THE SERVICE MANUAL, INSTALL THE NEW TAC- MODULE LISTED BELOW.

PART INFORMATION:

NEW TAC-MODULE PART # 25319443

PARTS ARE EXPECTED TO BE AVAILABLE ON APRIL 6, 1998 FROM GMSPO.

1 slow 97

Guys,

It only seems to happen when its raining out?? So it much be a moisture thing. Oh well it looks like I going to need to replace it. Any ideas on where to get one aside from the Dealer?? Thanks for the quick response. Again the forum comes through. :cheers:

Greg_E

Someone had a similar problem a while back. They replaced the TAC module andit didn't fix the problem. It turned out to be a bad ground. Apparently there are some ground connections near the fuse box under the hood. I'm not exactly sure where, as I haven't had a reason yet, to go looking for them. I would try cleaning and retightening those grounds before I started buying parts. If you search the archives, you might be able to find the thread.

01C5fan

I had the same codes and REDUCED ENGINE POWER problem. Happened several times this past summer. Usually during wot in 1st or 2nd gear. I did some searches (they actually worked then) in the archives and found a post that claimed to have cured it by cleaning the MAF sensors. Used Q-Tips and rubbing alcohol and swabbed the 3 sensors VERY gently. They were definitely dirty. Also cleaned my K&N filter which was overdue. This seems to have solved the problem. Haven't had it happen since. I mentioned it to the tech at my dealer and he just shrugged and said he didn't think that had anything to do with it, but he wasn't positive. Note that GM does not recommend cleaning the MAF sensors. Good luck.