Will turning off the traction control stop the Limp Mode function? I have a 99 and have been told my tractional control module can not be rebuilt like others. I have priced used ones and they are very expensive.

 

Limp mode may be the result of low battery voltage.

 

I do not think that is an issue as I put a new battery and alternator on it this spring. The Limp Mode has progressively gotten more prevalent each summer I drive it.

 

Low battery voltage is not the only thing that causes limp mode

 

The answer is no. Turning off your traction control will not stop this. Limp mode can be caused by many different things. Start with the easy stuff.

Did you pull codes to see which ones are populating? Have you cleaned your grounds? Have you tried opening your doors and wiggling the wire looms between the door and the car to see if the code goes away following this test? (Wires in the loom fray and cause a short in the system that throws car into limp. Happened to my 99).

Not enough info to really help you but first and foremost I would NOT immediately jump to the EBCM failing being the cause.

 

Yes, all grounds were pulled apart and cleaned last summer since I had an issue with the engine cutting out due to a bad ground. I will pull the codes tomorrow and see what I find, Thanks or the trick on the wire loom in the doors and next time I will try that and let you know.

 

I hunted the cause of this issue many years ago myself. I cleaned the grounds, replaced battery and alternator. Checked TBW connector, all was good, but still got the error.

I then paid close attention to what specifically took place every time it went into limp mode. It was not raining, streets were smooth, and it never happened when I had the car out alone. It only occured when I had a passenger. Then one day I pulled over on the side of the street to drop my wife off at an appointment. She closed the passenger door, I pulled away and car went into limp mode. I pulled over, open and closed the passenger door again and error message went away.

Got home did some reasearch and found that wires in the door looms wear through the casing and can cause a short. I popped the loom and inspected wires in the harness. Sure enough a very slight bit of wire exposed on (if memory serves) an orange wire. Teeny tiny rub mark where metal wire was exposed. I taped it all up and it didn't work. So I taped up just the single little wire with a very small piece of electrical tape. Just a small sliver wrapped once, is all I could get my fingers on. Then I wrapped the whole loom in more tape. 16 years later and the problem has yet to reccur.

Good luck!

 

Johnny,
Thank you for the info great insight! I have the limp happen while in my care by myself and also with a passenger in the car. I have noticed that it has been happening while I slow down to a stop and then when I try and pull off it kicks in and I have to pull off and turn the care off and it resets. Frustrating to say the least!

 

Next time it throws the code, instead of pulling over to restart pullover while keeping it running and try wiggling the looms between both doors. See if that has any impact. It could be the same issue I experienced.

 

Moved to C5 Tech.

 

Okay so it happened again today just warming it up in my garage. I backed it up to keep the fumes out of the garage and checked all the lights including hazards When I got back in the service traction control was on, so I checked the codes. The only codes for the traction control were 1278 and 1279. These came up under the 28TCS group.
I tried wiggling the wires in both doors while running and after a re-start with no change. Any help would be greatly appreciated!

 

Dang it. Was hoping you'd get "lucky" and it was the wires in the door looms. You said you did a full cleaning of your grounds. So it's likely not that.
It could be the EBCM. Which would suck.

 

Have you had the seats or the center console out recently? C1279 has to do with the yaw rate sensor and the parts associated with this code are located in those 2 areas..
Yaw-Rate Sensor: This solid-state device utilizes a tiny pair of ceramic tuning forks to measure the actual rate that the car is turning or yawing from the center line. This data is continuously fed into the Corvette's computer where the yaw rate is compared to the steering angle. Any variation beyond a pre-programmed set of values will result in activation of the Active Handling system's assist features. The yaw-rate sensor on the Corvette is located inside the center console.
Lateral Accelerometer: The lateral acceleration sensor measures the centrifugal force created in a turn. The data it provides is weighed against all of the other inputs and is used to calculate whether or not the car's limits are being exceeded for the speed and traction conditions that exist. This sensor is located beneath the passenger seat.

Just something to think about if you have done any work in those areas
Maybe Johnny Harcore will have somemore insight on these ideas

 

It could be the YAW sensor. It could be a few things. Good advice to trace steps and confirm if any recent work was done or if passenger seat was recently removed of maybe something got under there and disrupted the connection plug. Wedged water bottle etc .


I believe the 1278 is usually accompanied by other codes that actually cause the 1278. You cleaned grounds so I would retrace my steps and check for frayed wires or poor connections at the grounds, EBCM, YAW sensor under passenger seat, TAC module under cover panel in passenger wheel well. Some have found water in their TAC. Some have had the connection to the TB or a vacuum leak cause this error. Although the battery seems good and is somewhat new I would still have it tested.

Chasing this issues can be a pain in the butt. It was for me anyway. And it ended up being the wire looms. Which it doesn't seem to be the issue in this case.

 

Might be time to separate the star connectors and only connect the PCM and BCM together and see what happens. Maybe the cluster too so you can use it. If it drives right after that, add the other modules one by one and see which one causes it to act up.