| Subject: | Service Stabilitrak Indicator Illuminated DTC C0131 |
| Models: | 2007 Buick Rainier |
| 2007-2008 Chevrolet Trailblazer models |
| 2007-2008 GMC Envoy models |
This PI was superseded to update Recommendation/Instructions. Please discard PIT4576B.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
A customer complaint of a Service Stability Indicator illuminated at times and the EBCM DTC C0131 stored. The DTC may set a plausibility correlation fault if the Master Cylinder Pressure sensor senses hydraulic brake pressure with no brake switch input
to the EBCM. The driving conditions to induce this DTC are "Parade" type driving or as if the customer is at a "Drive Thru" window. These are typically light brake applications with slow vehicle movements.
Recommendation/Instructions:
- Using the Tech II, navigate to the EBCM's Data Display. Identify the parameter that displays Master Cylinder Pressure readings in Voltage and PSI. Does the Master Cylinder Pressure reading dynamically change output based on applying and releasing
the brake pedal? If yes, proceed to step 2. Otherwise, replace BPMV.
- Replace the brake booster with current SPO parts. After booster installation is complete, drive the vehicle on a few parade laps (with light brake apply) around the dealership lot verifying DTC C0131 does not return.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
