so, owned this our 1st vette since the start of summer - no problems which was cool (02 w/45K). last week took it out for a cruise as it was sunny, which is amazing for october here in washington where its usually 47 and cloudy! came onto the freeway around a slow turn on-ramp and gave it some throttle and got the "reduce engine power, service traction control system" message. So, after getting passed by a prius or 2 while i was doing 45 on the freeway, managed to get it home to check the codes. PCM 1221 and TSC 1278. Took it out for another drive-accelerated hard around a corner and same thing. After looking through tons of threads, looks like a throttle position sensor then? I read that the first thing to do is to clean the throttle body, as the blades may be getting hung up, and check the wiring for water/corrosion. If that doesn't do it, then the next step is replacing the throttle position sensor. Does that seem reasonable? FWIW i did take it out for a drive a 3rd time and romped on it pretty hard going down a straight and it was fine, which i thought was a bit weird but may just be a coincidence? So, i'm a corvette newb coming from vintage mustangs, so its a little intimidating all the electronics in this thing-very cool, but very intimidating! so be gentle-just trying to learn. Any help/advice if im on the right track would be greatly appreciated
jp

 

Moving this to C5 Tech.

 

Bump for the weekend. Weather looks like crap so i'll keep it in the garage and clean the throttle body. pulled off the throttle position sensor plug and no corrosion at all. I did notice that a few weeks before i had the problem that i got the "Active Handling Warming Up" message on the DIC a few times when i would first start driving, but everything i've read said that is normal-just interesting that i hadn't seen that all summer. Any suggestions would be appreciated and thanks all!
jp

 

The 1278 is causing the reduced engine power I believe. I was just doing a quick research and read a few things that may help and you could try..

tcs 1278 gets stored because of something going on with the pcm. possibly a failed tac module.

You can pull engine fuse box fuses 52 and 5 to disable the EBCM. If this stops the issue then you know where the issue is coming from.

 

the 1221 code will trip the 1278 tcs code... I had the same thing happen in my car oddly enough after doing a drivetrain swap which had absolutely nothing to do with it and nothing even remotely close was disconnected... it would run fine and the code would randomly pop up and then go into rep and run like dog crap... I replaced the tp sensor and it has been fine since... check the wires and make sure none are loose and make sure the pins are tight and making a good connection before replacing the sensor

 

Thanks guys for the responses. yep, read that the 1221 code would trip the tsc code. I will double check the connection as well like you suggested neutron. If it throws the codes again after i clean the TB up and check the connections, at least the TP sensor is an easy and relatively cheap fix ... and with all the electronic stuff that ive read about on this car, easy AND cheap i can live with