I had my 2008 Vert back for just a week after they replaced a brake module and it did it again. This time just 2 miles from my house and it never got over 40 mph that morning at 7AM. The service department said that it has "thrown several codes" but they have not found a problem. The owner of the dealership is driving it now. I was told that they are trying to get it to act up while they are driving it.

I asked where they will go from here and was told that they may call "TAC" for assistance. The service rep seemed uncertain about what they plan to do. They have had it for 2 days now and seem no closer to the answer.

This is the 4th time that it has been in the shop for the same thing this year. I bought a new battery from them once when they told me that it was the problem.

Generally when it happens, if at cruising speed, it has a disconnect between the engine and the transmission--i.e. engine freely revs but no power to the wheels. It then has all gauges acting up and the car has even shut off on its own (though this generally does not happen). When restarted the car, an A6, will not go above 2nd gear.

It has not been raced and is an only a Daily Driver.

Does anyone have any thoughts?

 

obone,

Could you send me your information (name, number, address, VIN, current mileage, and involved dealership) so I can check into this situation?

Evan, Chevrolet Customer Service

 

Done. Thanks

 

It has been in the shop for a week and still no answers. This rental/loaner is starting to get old. I miss my Vette!

 

I had the same issue with my 08, in the shop for 2 days. The tech read the codes and said he did not know what the problem was. He said he needed to see it happen himself but after the car was towed in it would not start for him and they had to push the car by hand into the shop he read the codes and could not do anything except reset the codes. I took my car back, stupid people, I will never return to this dealership for anything period. I checked the connections on my front wheels and the connections on the black sensor on my transmission on the passengers side of the car. I think that is the TCM. It has bee good for 2 days now, keeping my fingers crossed. If I have trouble again I will go to Bill Black Chevy and give them a shot. Would like to know how you make ot.

 

They have checked all of the connections and now they are looking at changing modules out.

 

Evan, I was told that I would hear from Matt with an update within 48 hours but still no call. I have been in a rental for over a week, again, and the local dealer still tells me that they are checking the connections. Do you have any advice?

 

[QUOTE=obone;1582620885]Evan, I was told that I would hear from Matt with an update within 48 hours but still no call. I have been in a rental for over a week, again, and the local dealer still tells me that they are checking the connections. Do you have any advice?[/

Go to another Dealer.

 

Have they told you which codes have shown up? The EBCM can send a torque reduction request to to the ECM and it could call for it to reduce torque to zero. If that doesn't stop what it senses as the rear wheels from spinning it will then apply the rear brakes. I tested this on my C5 by swapping the front and rear wheels and the car wouldn't coast down hill in neutral without me turning off traction control. As my C5 exhibited this usually comes about due to a wheel diameter issue but it can happen if there is something that is affecting one or both rear wheel speed signals. That could be interference from an ignition source such as a bad wire, arcing at the spark plug, or some other electrical noise transmission coming from some other part of the high voltage part of the ignition system. Wheel diameter issues will not cause codes because the system thinks it is operating correctly. Electrical interference may not cause codes for the same reason. In these cases the problem should go away if you turn off traction control. Another way to eliminate the ABS system (EBCM) is to pull the fuses to the EBCM. Without electrical power it is dead and can't do anything so the power train should work properly.

Revving the engine in neutral doesn't cause torque reduction since there is almost no torque being produced but once your are in gear you can get it and the car may not be producing enough torque to go above 2nd gear.

Bill

 

They say that it just shows loss of communication along several circuits.

 

OH, do I know that light, I've been living with it for a couple of years now. Good luck seems like most dealers can only trouble shoot by replacing parts any more. Seams like GM could have done more to help the technicians trouble shoot these modules than the tech 2 seams to be providing.

 

The EBCM, ECM, TCM, VCIM and BCM are all part of the GM High Speed LAN. Debugging that can be a little tricky. Issue could be a problem in be wiring, connectors, a single module that is causing problems with the other modules. Not sure what capabilities the Tech 2 has but I suspect troubleshooting LAN problems is on the edge of most mechanics capabilities. They really aren't network technicians who have been extensively trained in how networks actually work and spend a lot of their time solving network issues. It is the difference between a Generalist Vs a Specialist and one of the reasons they probably need to involve the TAC.

I attached a LAN schematic so you could see what they may be dealing with.

Bill

 

obone,

You're district specialist should be contacting you today.

Evan, Chevrolet Customer Service

 

Evan:

Do you have a district specialist in the Savannah GA area????

 

I never got that call. But I have my Vette back with a gadget for recording any events if it happens again. They never found anything.

 

05C6GAC,
District specialists are generally dependent on the location of your dealer. Are you currently experiencing a concern? Feel free to contact me via email at tricia_marie@gmexpert.com if you need additional assistance. Thank you.

Tricia, GM Customer Service.

 

It did it again. Two days after picking it up. They left me a large recorder sitting in the cup holder but you have to turn it on every time you start the Vette. My wife was driving it and failed to turn it own when she started up but did turn it on after getting the service light- I doubt that this helps. It is very frustrating. They have stated that it could be caused by my Valentine 1 but I sent it back for the upgrade and it was not even in the state.

Does anyone have any suggestions. Apparently TAC has told them to just check all of the connections. Which they tell me they have done.

 

Old Thread but the problem has resurfaced. The last time I road around with the Chevy event recorder filling my cup holder for nearly 2 years. Eventually someone listened to me. I was telling them that it would act up when I forgot to turn on the recorder but never when it was on. For those that have never had to use this, it is so large that if it is in the cup holder it blocks the second holder. It also must be turned on each time you start the car and then a button must be pushed to record the event. This past May 2014 I was finally able to convience the dealership that there must be a bad body motion sensor, which they confirmed and replaced. I have had no further problems until this week when it did it again. I scheduled an appt to get it in this week but within one day everything went crazy and my dash looked like I was flying through the Bermuda triangle with every light and gauge going haywire. I have within the past 3-4 months had a throttle issue where I thought that it was loosing power at idle. I was told that I needed a new "lifetime" alternator==total service charge $1000. 2 weeks later I was having the throttle issue again and was told that it was a plug wire==$300+. Now that it is in the shop I'm told that with 30+ codes that my battery is bad. I have had no problems with it cranking and had the battery checked with the alternator replacement was done by 2 different places and was great at the time. I do not know if this dealership is taking me for a ride but they are the only dealer in the area. I have moved since my last post and live in southwest Missouri. I know that I'm venting but I have not read about any consistent problem that seems to fix this. Any ideas would be great. I bet the service rep that replacing the battery would not be the fix for the 30+ codes and 12 sensor that were abnormal--I bought the battery.

 

two places to look are the battery cables, make sure the ends are clean and tight, next check the ground cable on the block (passenger side) and the connection on the starter from the battery, this is known to come loose.
HTH

 

I had that problem and after a few times of changing the steering sensor the brake module and other things the tech said it runs to cold that he let it idle and it never warmed up, that it has to hit a predetermined temp within a certain cycle time, me driving it would run cool, so I started letting it warm up to 167 degrees before driving, and it never happened again, so i tried it a couple more times not warming up, and the symptoms returned, so now I always let warm and hasn't happened in years