Diablosport Forums

I have a U7135 for my wifes '05 300C AWD. When I plugged it in the first time, it required that I flash the PCM with a calibration update, which I did. I then flashed it with the 91 octane canned tune. I changed the cooling fan settings, and firmed up the shifts.

Now, the speed control only works above 70 MPH. When you first start, you can turn the speed control on, and the light will illuminate. As soon as the car goes above 10 - 15 MPH, the light goes out, and cannot be turned back on until the car comes to a complete stop, or the car is over 70 MPH. Once the car goes below 70, the light goes out, and will not turn back on until you go over 70, or come to a complete stop.

I have returned to stock, but the problem is still there. I've downgraded the Predator to the 9R12 from the 9R27, still no luck. The speed control worked perfectly prior to this.

Thoughts?

I just got back from a road test with a scan tool connected. The PID for speed control denied status changes to "S/C Switch DTC" when the speed control stops working. I can find no Speed Control Switch DTC's in any modules. There are no SRS DTC's, either; hoping to eliminate the clock spring as a possible concern. There were a couple of module configuration DTC's (VIN Mismatch, and Implausible configuration) in the ABS module, but clearing them made no difference, and they have not returned.

Good luck with this issue.
Many of us have had similar issues with U7137 and no response
from diablo.
Mine works up to 60mph then kicks off.
At least it is somewhat useable.

I have a friend that is an instructor at a Chrysler Training Facility. I ran this issue past him, and he found a service message pertaining to speed control issues after a PCM reflash. The fix is a PCM reset with a scan tool; not just disconnecting the battery. I own an inexpensive Mac Tools scan tool, and this does not have the capabilities. However, where I work, we have a Launch scan tool, and it does. Resetting the PCM fixed my issue.