Vehicle: 2013 Chevy Traverse, AWD, V6-3.6L, Automatic Transmission/Transaxle
Problem: The vehicle owner said that the hill start assist system would not release the brakes after stopping on a hill and trying to accelerate. Editor’s note: The hill start assist system is designed to temporarily hold the brakes on while stopped on a hill until the driver can release the brake pedal and push on the accelerator pedal.
Case Details: The technician connected a scan tool and found no diagnostic trouble codes. He also verified that the vehicle did have the hill start assist feature. The rear brake shoes were worn out, so he replaced them. He also replaced the electronic brake control module (EBCM). Unfortunately, that did not fix the problem. At this point he called ALLDATA Tech-Assist.
The Tech-Assist consultant asked the technician to verify brake switch input to the EBCM. He also advised him to open front and rear brake bleeder valves one at a time to see if the brakes released.
The technician verified there was brake switch input and that the brakes would release if a bleeder valve was opened. Testing pointed to an ABS hydraulic solenoid valve sticking in the ON position. It is part of the brake pressure modulator valve (BPMV), (ABS Hydraulic Unit).
Confirmed Repair: The BPMV was replaced, and the brake system was bled as per the procedures in ALLDATA Repair. After the repairs, the hill start assist feature operated normally. Fixed!