I have all these three lights coming on simultaneously, if I shut the car off and restart, they all go out and stay out. When I shut the car off and come back to restart, they are all on again, but if I shut the car off and restart, they all go off and stay off again, very puzzling, the car is showing code C0550. Has anybody else had this issue?

 

There should be two more numbers like 00 or something

 

Probably the electrical supply to the ABS computer.

 

C0550-00, very cold this morning, went out started and restarted this time and they all stayed on, I will see what happens when it warms up outside, I'm beginning to think there may be a temperature component to this issue?

 

Tighten those 4 bolts


These 4 , 7 mm bolts

 

Tightened bolts, same issue, ran scan when lights out, no codes, when lights on, code C0550-00, simple restart clears the lights and code, I'm guessing either wire or something internal to ABS or ECM module? This is one of those gremlins, cleaned ground terminal and removed cleaned and reconnected computer plugs.

 

You don't happen to have the pinout on the plug to the ABS computer so I can check the voltage?

 

Hope this helps

 

See post #4

https://www.chevyhhr.net/forums/prob...on-ebcm-64754/

 

Link in my sig to FREE shop manuals.