My 1998 Coupe got the gremlins today !! About 6 blocks from my house today, the Vette suddenly slowed down to 5mph. The dash DIC read "Reduced Power" tThe face of the dash had a picture of a Vette laying rubber, while next to it read, check and a picture of a engine. I turned towards home and at 5 mph I slowly made it home. I had tried pushing the Traction Control button, but it didn't do anything. So I got it home and turned it off. (I was afraid to turn it off, while I was not at home). The Traction Control picture was gone, but the Check engine was still there. I took it to a guy I know and he scanned it and got the 1518 code. He checked the throttle sensor, and determined it wasn't the throttle sensor. He then opened the passenger side cover for the electronics and the passenger wheel well one as well. The book he had didn't tell what to do so he couldn't determine what was wrong. I called the dealership, "Jack Cauley" and made an appointment for Thursday. About 3 hours later I had to move the Vette and when I started the car up, no check engine light. Turned it off again and restarted it, again no check engine light. I repeated this a few more times, no check engine light. What the heck is going on with this car. The code 1518, was the only one that would come up when it was scanned. Could anyone tell me, was this just a small glitch or should I take it to the dealer tomorrow. I am planning on a 800 mile trip to Kansas City, on Sunday, so I'm a little worried about taking the Vette. Should I take it to the dealer and let them have a shot or just go on the trip and don't worry about it???????? Any help or advice would be appreciated........

 

See if you have any codes in memory. Make sure you note the entire code for instance C1226HC is a complete code. You may also see it with only one suffix which would be an H.

Take a look at:
http://www.stengel.net/diccodes.htm
on how to obtain the codes. It is quite easy to pull the codes.

 

Hey Jim, I have a 98 MN6 and experienced the following. I sent an e-mail to a friend and his reply is included below. hope it helps:
I do not think that you are missing anything simple here.

The key to remember is that the TAC module is the most critical part of the engine acceleration. If the PCM cannot communicate, then the PCM will default and not allow acceleration because it has no idea how to respond to gas pedal inputs.

You could have a bad TAC module, which is somewhat common on the 97-00 models.

As for the c1278, this is a byproduct of the P1518.

C1278, C1288 are usually steering wheel position sensor problems. The steering column would have to be removed.

Please keep me posted, c4c5
I searched through the CAC tech section and found some but not all the answers I need. Maybe you can give me a minute of your time for help?
I stopped at a traffic l;ight, and got the DIC message for Service Traction Control and Reduced Engine power. 98 MN6, did not stall, but with the accelarator floored could barely make 1 mph to get to side of road. DIC retrieved codes, AFTER 3 starts (ignition cycles) are:
PCM: P1518H "PCM to TAC module serial data cricuit", TCS: C1278H "TCS Temporarily inhibited by PCM", C1281H "Steering Sensor uncorrelated malfunction" (I know what I nned to do for this, but haven't had time to perform service manual diagnostics and possible sensore recal or replacement), C1288H (can't find in any documents I have) and IPC: U1160H "Loss of communication with LDCM"
I know all the codes are H and not Current, but the Check Engine Light is still light, Vette 'seems' to be driving normally now.

 

The dealer (Jack Cauley) checked it out and it was the TAC module, cost was 1 hour time charge for labor and 1 hour diagnostic charge and the TAC module was $299.00. So far the replacement of the TAC has solved the problem. But it has only been driven for the 35 miles home from the dealership. I am going to KCMO on Monday (800 miles) so we'll se what happens......