Braking Sensor/Switch: Service and Repair

Brake Master Cylinder Primary Piston Position Sensor Replacement

Removal Procedure

Note: The ignition must be in the OFF position, without pausing at ACCESSORY, and without applying the brake pedal to ensure the brake modulator and high pressure accumulator (HPA) pressure relief occurs. This process will take approximately 1 to 3 minutes.

1. Turn the ignition to OFF, without pausing at ACCESSORY, and without applying the brake pedal.
Remove the ignition key.
2. Wait approximately 1 to 3 minutes until the brake modulator and HPA pressure relief is complete.
3. Disconnect the brake master cylinder (BMC) primary piston position sensor electrical connector.




4. Remove the 2 BMC primary piston position sensor screws (1).
5. Remove the primary piston position sensor (2).
Tilt the rear of the position sensor downward and remove the sensor.

Installation Procedure




1. Install the BMC primary piston position sensor (2).

Caution: Refer to Fastener Caution Fastener Caution.

2. Install the 2 primary piston position sensor screws (1) and tighten to 10 Nm (89 lb in).
3. Connect the primary piston position sensor electrical connector.
4. Inspect the battery state of charge. Refer to Battery Inspection/Test Battery Inspection/Test.
5. If necessary, connect a battery charger to the 12V battery. Refer to Battery Charging Procedures.
6. Install a scan tool to the vehicle.

Note: The ignition switch must remain in the ON position with the engine OFF during this procedure.

7. Turn the ignition ON with the engine OFF.
8. Using the scan tool, perform the following steps:

1. Select Diagnostics
2. Select the appropriate vehicle information
3. Select Chassis
4. Select Electronic Brake Control Module (EBCM)
5. Select Module Setup
6. Select BMC Primary Piston Position Relearn and follow the instructions on the scan tool