Diagnostic Test

1) BRAKE FLUID LEVEL SENSOR SIGNAL VOLTAGE BELOW 0.10 VOLTS
NOTE: This DTC must be active for the results of this test to be valid.

Turn the ignition on.

With the scan tool, read Brake Fluid Level Sensor Signal voltage.

Is the voltage below 0.10 volt?

Yes
1. Go To Step 2).
No
1. Refer to the INTERMITTENT CONDITION diagnostic procedure. (Refer to BRAKES - DIAGNOSIS AND TESTING - ABS-INTERMITTENT CONDITION) .
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
2) CHECK BRAKE FLUID LEVEL
NOTE: Visually inspect for worn brake linings or undersized rotors.

Was low brake fluid level found?

Yes
1. Repair as needed.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
No
1. Go To Step 3).
3) BRAKE FLUID LEVEL SENSOR INTERNAL FAILURE
Turn the ignition off.

Disconnect the Brake Fluid Level Sensor harness connector

Turn the ignition on.

With the scan tool, read the Brake Fluid Level Sensor voltage

Is the voltage approximately 5 volts?

Yes
1. Replace the Brake Fluid Level Sensor in accordance with the Service Information.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
No
1. Go To Step 4).
4) CHECK THE (B20) BRAKE FLUID LEVEL SENSOR SIGNAL CIRCUIT FOR SHORT TO GROUND

Fig 1: Checking (B20) Brake Fluid Level Sensor Signal Circuit For Short To Ground
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the Totally Integrated Power Module harness connector.

Disconnect the Brake Fluid Level Sensor harness connector.

Measure the resistance of the (B20) Brake Fluid Level circuit in the Brake Fluid Level Sensor harness connector to ground.

Is the resistance below 100 ohms?

Yes
1. Repair the (B20) Brake Fluid Level circuit for a short to ground.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .
No
1. Replace and program the Totally Integrated Power Module in accordance with the Service Information.
2. Perform ABS VERIFICATION TEST. (Refer to BRAKES - STANDARD PROCEDURE - ABS VERIFICATION TEST) .