The DTCs 1586-00 and 1586-04 are for detected circuit faults for the RH park brake actuator circuit.
The park brake system on the Gen2 volt is completely different from the Gen1 as instead of a single motor that operates the park brakes with a pair of cables to the calipers (a lot of GMs use this system) the Gen2 use motorized actuators at each rear caliper and controlled directly by the Electronic Brake Control Module (EBCM).
The bulletin listed 17-NA-146 basically recognizes that there has been some intermittent connection issues triggering these codes (or possibly those for the LH side, or both sides) and discusses inspecting the EBCM (NOT ECM as the work order states) connector and harness for a chafing against the drive unit/transaxle mount and to reroute as required.
The same bulletin also state to inspect the connection at the park brake actuator/s and to add dielectric grease for a possible fretting issue. Fretting is when a high frequency vibration or resonance causes an electrical connection to be disturbed, potentially triggering a DTC.
This bulletin specifically applies to EBCM DTCs C1138 , C1148 , C114C , C1586 , C1587 , C1588 with ANY symptom suffix (-00 -04 -0B -0C -0F )
So for now, it appears they have simply followed the bulletin process to the letter.
Hopefully you will not get any further park brake messages or ABS warnings in the future.
HTH
WopOnTour
The park brake system on the Gen2 volt is completely different from the Gen1 as instead of a single motor that operates the park brakes with a pair of cables to the calipers (a lot of GMs use this system) the Gen2 use motorized actuators at each rear caliper and controlled directly by the Electronic Brake Control Module (EBCM).
The bulletin listed 17-NA-146 basically recognizes that there has been some intermittent connection issues triggering these codes (or possibly those for the LH side, or both sides) and discusses inspecting the EBCM (NOT ECM as the work order states) connector and harness for a chafing against the drive unit/transaxle mount and to reroute as required.
The same bulletin also state to inspect the connection at the park brake actuator/s and to add dielectric grease for a possible fretting issue. Fretting is when a high frequency vibration or resonance causes an electrical connection to be disturbed, potentially triggering a DTC.
This bulletin specifically applies to EBCM DTCs C1138 , C1148 , C114C , C1586 , C1587 , C1588 with ANY symptom suffix (-00 -04 -0B -0C -0F )
So for now, it appears they have simply followed the bulletin process to the letter.
Hopefully you will not get any further park brake messages or ABS warnings in the future.
HTH
WopOnTour
