went on a road trip today and the service traction system message came up on the DIC

can anyone help me please!!!


have any of you ran into this problem before?


what is usually the solution? besides put it in the shop


thanks for any help

 

It could be a lot of things. What codes show up on the DIC?

 

I dont know how do I check?

 

Here ya go:

http://corvetteforum.shelor.net/Docs...d_Diagnostics/

 

thank you kind sir

the code was C1277

now how do I find out what that code means?

 

There is a sticky on top of C5 tech section - check it out.

I am getting this code randomly as well, and have not been able to diagnose it

 

What year car do you have? A description of the problem from the Service Manual.
DTC C1277 or P1571
Circuit Description
The EBCM and the PCM simultaneously control the traction control. The PCM reduces the amount of torque supplied to the drive wheels by retarding spark timing and selectively turning off fuel injectors. The EBCM actively applies the brakes to the front wheels in order to reduce torque.

The EBCM sends a requested torque message via a pulse width modulated (PWM) signal to the PCM. The duty cycle of the signal is used to determine how much engine torque the EBCM is requesting the PCM to deliver. Normal values are between 10 and 90 percent duty cycle. The signal should be at 90 percent when traction control is not active and at lower values during traction control activations. The PCM supplies a pull up voltage of 5 volts that the EBCM switches to ground to create the signal.

The PCM sends a delivered torque message via a pulse width modulated (PWM) signal to the EBCM. The duty cycle of the signal is used to determine how much engine torque the PCM is delivering. Normal values are between 10 and 90 percent duty cycle. The signal should be at low values (around 10 percent) at idle and higher values under driving conditions. The EBCM supplies a pull up voltage of 12 volts that the PCM switches to ground to create the signal.

When certain PCM DTCs are set, the PCM will not be able to perform the torque reduction portion of traction control. A serial data message is sent to the EBCM indicating that traction control is not allowed.

You need to check the EBCM and PCM grounds to make sure they are clean and making good contact. That means checking where they are fastened to the frame and in the splice packs as well. For front mounted EBCMs the ground is at G108 for rear mounted EBCMs the ground is located at G402. The PCM ground is located at G106. If those are OK then you need to check the requested torque signal wiring between the two modules and the voltage level of the signal. If the problem isn't in the grounds or the wiring then its either the PCM or the EBCM.

Since you don't mention a Service Active Handling message I am assuming your car may not have Active Handling and is either a 97 or 98 with rear mounted EBTCM or a 98 through 00 with front mounted EBTCM.

Bill

 

I know that you are running 22" wheels in back - what size tires are you running front and back? If the front tire overall diameter is taller than the rear - regardless of the wheel size, you might encounter issues with the traction control system.

 

Did you ever figure out this problem?

 

I am struggling with this issue currently also.

 

 

I am too. I have the same size tire front and rear.

245/40/18. I just shut off traction control but it is still irritating.

 

Did the problem occur around the time you got that wheel/tire combo? It is my understanding that the front/rear have to be different sizes or you will have problems.

 

 

Yes it happened at the same time. What is the deal with having to run a larger tire in the rear? Can I just shut off the traction control and not affect anything or will this eventually cause a problem?

 

I had this problem too - every few weeks, I'd receive both the Service Traction Control message and Service ABS one at the same time. The only time I'd receive them was when I started the engine.

Replaced my battery and all is happiness once again.

 

The traction control system expects the rear tire/rim combination to be larger than the front. I don't know of any long term problems, except that you will be without your active handling and traction control.

That isn't the safest thing to do IMO.

 

I've been running 19x35s all the way around on my car for 2.5 years and have not had this problem?

 

running 20s on all 4 no problems!

 

In my 99 FRC I had a battery problem (bad cell - no leakage) and these two codes P1571 and 1277 popped up. I have replaced the battery but they are still there and will not reset....

Any suggestions?