Service Stabilitrak Indicator Illuminated DTC C0131 - keywords booster brake drag DTC lamp light pedal shake stability vib vibration VSES wear

This PI was superseded to advise dealers to first order a booster from SPO and look at julian date. Please discard PIT4576A.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

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.

1. 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.



2. Replace the brake booster with current SPO parts. Once the part is received, inspect the julian date code that is located on the booster's bar code. Please refer to call out #1 in the illustration above that identifies the bar code sticker. Rotate the booster so the bar code is positioned as shown in call out #2 above and read the julian date code from left to right and document the number on the repair order. This date is difficult to read and cannot be easily identified with the booster in the vehicle. Prior to booster installation, be sure the julian date is 18058 or greater. If the julian date is lower than 18050, order a second booster. If the second booster is below 18058, contact Technical Assistance to create a TAC Case. Dealers will get a return call within 24-48 hours to discuss this concern.

Example Julian Date: 18058

1 = 1st shift

8 = 2007 Calendar Year

058 = Built on the 58th day of the year.

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.