Voluble

Hey all, we recently had an issue with the girlfriend's 08 Equinox AWD 3.4L. She was driving at highway speeds and the Stabilitrak, ABS, and Parking Brake lights started flashing and stayed on. I went out and got a code reader that could read ABS codes and pulled up C0550:00. Also in a different section of the code reader I was able to pull up P1779. Anything I should be looking for? I've been searching around the internet but haven't found much help. Looks like it could be a myriad of issues from wheel speed sensor to EGR valve.

Thanks

mountainmanjoe

Clear the codes and see what comes back. Hopefully it's just a glitch. Test your battery+alternator to make sure everything is OK (low voltage can cause weird electronic issues)
If it keeps coming back then may be looking at a failed control module unfortunately.

P1779: torque steady state signal to the ECM is invalid.

DTC C0550 00: Electronic Control Unit (ECU) Performance

Voluble

The C0550 code keeps coming back on immediately after clearing it. I played around with the scanner some more and also pulled up code C0561-71

mountainmanjoe

it's another electronic control module related fault

DTC C0561 71: System Disabled Information Stored Invalid Serial Data Received

mountainmanjoe

If the vehicle drives fine, I'd be inclined to ignore these. It's likely an expensive issue to diagnose and fix, and probably not worth it for a 15yo vehicle.

Voluble

As far as I can tell it runs and drives like normal. Thank you for the information

ruley73

Check your brake fluid level. It's not normal for the red brake light to come on in conjunction with the others.

Voluble

Brake fluid reservoir is full. I ordered a new parking brake switch to try swapping that out. It was 6$ so I figured why not. If that doesn't do it then I think we're going to take it in to see if anyone can diagnose it and then I'll do the repairs.

​​​​​​I guess I got the original story wrong, girlfriend was driving through a neighborhood and the abs and stabilitrak lights flashed then stayed on. The parking brake light did not come on until sometime after. We did take it on a 4 hour round trip yesterday and it drove totally normal.