2011 Chevy Equinox Random Traction Control and Check Engine Light

[chevyguy]

I'm having an issue I can't seem to figure out. I have a scanner and was able to pull some codes but here's what' happening. 

Randomly, the car will loose power, traction control light and check engine light come on. Here''s what comes up:

 

U0100-71 Lost communication with transmission control module-invalid data (brake control module)

U0100-71 Lost communication with transmission control module-invalid data (brake control module)

P0300-00 Engine misfire detected (ECM)

P124B-00 Cylinder 4 injector high control circuit shorted to control circuit

Cleared the codes and the car ran normal for a day or so, then same thing happened and same codes. Took the plastic off the engine and inspected wiring, wiggled wires to see if I can get it to happen again thinking maybe there's a break somewhere with the loss of communication. But nothing.

Ran it again fine, but then started to misfire and lights came on. Codes this time were only:

U0100-71 Lost communication with transmission control module-invalid data (brake control module)

U0100-71 Lost communication with transmission control module-invalid data (brake control module)

P0300-00 Engine misfire detected (ECM)

 

I also recall a few months ago, a couple of times my radio would turn off and on by itself like it lost power for a second. This made me think I had some sort of communication or loose power somewhere. I did install a new alternator and battery like 6 months ago so I checked all connections and they are fine. It's random.

What could it be?

• Bad injector but intermittent? Don't they usually just go bad?
• Shorted wiring causing intermittent issue or loss of communication back to control module?
• Brake control module issue?
• ECM issue?

 

 

[chevyguy]

Replaced the #4 fuel injector and that seemed to have solved the issue.

[chevyguy]

Here the rail...I ended up removing the wrong injector. #4 is closer to the drivers side. I followed a wrong online diagram for firing order!