BenC5

. . . here was my scare that happened to me tonight, about 1 1/2 hours ago. I was coming up an on-ramp, about 60 mph accelerating up to 70-75, all of a sudden, engine seems to die and ALL the warning lights go on and I'm decelerating on the highway. "service traction control" and "service active handling" come on along with the "reduced engine speed" so I limp off the highway as the engine won't rev over 1,200 rpm. ****!

I shut the car down and look through the owners manual. It says to wait at least 10 seconds and I wait a lot longer as I'm reading all there is on the check engine light which says that I might have left the gas cap off or did not screw it on tightly, it is not that as I never not put the gas cap on or put it on cocked. I did not drive through a big puddle so the wiring is not wet, reallly, it says that in the manual, and the 3rd thing is that I don't think I have bad gas in the tank, I could, but I doubt it.

So I fire the car up and it starts and I put it in gear and expect it to limp me home, thankfully I was not far from home and lo and behold, the car seems like it is running fine again, not all rough and limited in power. Only thing is the check-engine light is on but I get home. So I get on the computer, find out how to check the engine codes in the DIC, forums are awesome!, and I find all of the 12 codes that are all History codes in that there was an H at the end of all 12 and 4 of them have to do with the battery being disconnected, one is the RF tire sensor that went out on me sometime this past Friday.

I wrote them down then cleared all of them. I looked up all the codes and none of them seemed that serious. Here are a few more;

28 TCS C1278 H This has to do with the Traction Control, not sure exactly what though.

10 PCM P 1514 H I think this is a throttle body sensor or something.

Those 2 were the only ones that had/have me concerned.

I started the car and the check engine light went off which made me very happy. I have a 90-day/3750 warranty on the car from the used car dealer I bought it from, but what might/should/would you do? I'm hoping that when I drive tomorrow, I don't have any issues. I'll look forward to your replies. Thanks.

ColeTrain'sC5

if you have a warrenty, bring it in

Y2Kvert4me

Is your car stock or modified?

The P1514 is what set off the reduced power mode. What that code basically means, is that the PCM "saw" more airflow into the engine than expected at that given RPM and throttle position. It's basically a sanity check of the electronic throttle system.

The C1278 is a sympathy code that means the TC system was inhibited by the PCM, which can occur when the P1514 is set.

It sounds like you are a new owner to the car, so you may not know what's been done to it...but if it's a heads/cam, or blower car...it is possible this a tuning issue and something that a dealer won't be able to help you with.

More info about the car could help get you better answers.

freakshow_Z

Same thing happened to me. I don't remember the exact codes but a new TPS and EBCM fixed me right up. Thank goodness for my warranty!!! Don't take chances, it will most likely happen again.

BenC5

I was accelerating a bit faster than usual/normal when the whole kit and kaboodle shut down.

The car did come with a K&N intake and the filter along with a Borla Quad Stinger on the back. No blower or turbo.

All the codes that came up were History codes as they all ended in "H". I have been doing a lot of reading using the Search of "Check Engine Light". and hopefully I'll get no more. I'll see how things go in the morning. Up till tonight, the car has been pretty excellent.

Tech

I wouldn't have cleared the codes. You should take it back, document it, then clear the codes and see if it goes away. That way if the issue resurfaces in 4k miles, you'll have something to refer to when you have to fight the dealer.

DeeGee

If its any consolation I had a similar problem shortly after I bought the car (03). It was a one off and never occurred again.

Even so I'd write to the dealer and explain what happened. I'd just warn him that you won't follow up now as it cleared but that it occurred within the guarantee period and that if it becomes regular you'll expect him to work it under the guarantee. JMHO

capehorn3

Read the electrical sticky at top of forum and clean all your grounds & batt. connections. Hit any bumps/rumble strips on ramp?

XLR8BYU

Hit happened to me twice last year. It was a combination of a bad ground near the left front and also a very low battery from sitting w/o a battery tender while at the body shop getting painted. Once I changed the battery, it never happened again.

BenC5

Thankfully, on the drive in this morning, 25.2 miles, the car did not hiccup and as the traffic was very light compared to the usual M-Th traffic, I was able to duplicate the "acceleration" I was under last night when the car went to "reduced power". I was not able to get the car to get all the warning lights on again, thank goodness. I will;

1. Call the dealer and let them know that it happened. A very good piece of advice, so that they know what and when it happened as I still have a good 9-weeks of Warranty left.

2. I will go and find as many of the grounds as I can and clean/sand/dielectric grease- them and re-screw/re-bolt them.

3. I will hope and pray that I don't have any other issue(s) with the car as when I'm at 80-85 and the pavement is smooth, the car is just heavenly.

Thanks for all the advice, as always, it is truly appreciated.

dgrant3830

Sort of sounds like the throttle position sensor is failing...but please let us know once you find out from the dealer.

BenC5

Absolutely will let all know what I might find out. I'm hoping that between the drive back home tonight and the driving that I'll be doing this weekend that nothing untoward will happen. If anything does, I'll go to the dealer on Tuesday and have the car looked at.

RPMaddiction

I wish you had kept your promise to report back. I had this exact thing happen to me on the track 4 times today. They finally kicked me out for the day. Now I am left clueless. I noticed it happens primarily when turning hard left. Any ideas? Sorry for bringing up an old thread but this was a very bad day at the track.

REKCUF

I had the same experience as you on my last autocross event. Although it only happened once to me. I disconnected the battery for a few minutes & it hasn't happened since.

runner140*

Seven year old post and no conclusion....

BenC5

I do miss that 2001 C5.

Way back when, I had gone through and cleaned, sanded/di-electric greased all the grounds in the vehicle and the problem/issue never came back.

I had to trade the car for a sedan in 05/2011 on account of my second child having been born. She is 5 now.

RPMaddiction

The build is brand new and she ran perfect the first 5 sessions a month ago. Not this. I'm pulling all the codes and translating them today. There are a lot. I hope its the pedal assembly to be honest. Although a ground is cheaper to fix, the trouble of hunting it down is a nightmare.

BenC5

There is a thread somewhere, that will show where, I think, the 5 or so major ground points are. They are all easily accessible once you know where to look for them. Once you clean them all up and reattach them, I'll bet your codes will all go away. There is no reason why so many codes come up all at once and usually it is low voltage and/or, the bad grounds that trigger them all at once.

Search the forum for the thread on the grounds. It had solved my problem.

Chicago1

This first link is pretty awesome...https://www.corvetteforum.com/forums...re-report.html

Bill Curlee

RPM

Clear all of your DTCs. Other than being on a TRACK, can you replicate the issue??

When the issue happens, "WITHOUT TURNING OFF THE IGNITION" Press RESET to clear any urgent messages in the DIC and once all the messages are cleared, READ ALL the DTCs and post them.

Post the ones that show up during that current KEY ON engine run period.

Normally, a REDUCED ENGINE POWER event is caused by:

1. The PCM seeing a LOT more air flow than was expected.
2. The Throttle Circuit / Accelerator Peddle circuit is seeing an illogical condition.

Check all of the air ducting connections between the MAF and the throttle body. Make sure that they are secure and air tight. Any UNMETERED AIR is a bad thing.

Check all of the electrical connections, wiring and throttle system components. Make sure all the connections are tight and the wiring is in good shape.

GROUNDS. All of the ground connections on the chassis are NOT WEATHER TIGHT. So, that means water can and will get into the connectors and cause corrosion. Take off each ground connector. DISASSEMBLE the connectors G-xxx and examine the ground buss pins and the G-XXX Female pins for corrosion and damaged pins.







Some grounds are only an eyelet connected to the chassis by a stud and nut:



Some grounds terminate in a SPLICE PACK (SP-XXX) and one wire inside the splice pack goes to a common chassis ground:





Hope this helps

Bill


Both conditions will set a specific DTC. So, try to get the related DTCs posted.

Bill