Pinpoint Test Aw: Brake Lining Wear Sensor Faults
- Refer to Horn/Cigar Lighter
for schematic and connector information.
Normal Operation and Fault Conditions
The ABS module uses 2 normally-open switches, connected in series, to monitor the wear of the brake pads. As the brake pads wear, the switches close. Once fully closed, the ABS sends a message to the IPC to display a warning in the message center.
DTC Fault Trigger Conditions
DTC Description Fault Trigger Condition ABS C004A:13 Brake Lining Wear Sensor: Circuit Open This DTC sets when the ABS detects an open circuit condition in the brake lining wear indicator circuit. Possible Sources
- Wiring, terminals or connectors
- Brake pad wear indicator
NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector. - AW1 CHECK THE ABS (ANTI-LOCK BRAKE SYSTEM) BRAKE LINING WEAR SENSOR CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect ABS connector, C135 .
- Disconnect Left Front Brake Pad Wear Indicator Switch connector, C1687 .
- Disconnect Left Rear Brake Pad Wear Indicator Switch connector, C4427 .
Is the resistance less than 3 Ohm?
Yes GO to AW2 No REPAIR the affected connectors or terminals. Refer to Wiring Diagrams for schematic and connector information. - AW2 CHECK THE REAR SENSOR TO FRONT SENSOR CIRCUIT FOR AN OPEN
Is the resistance less than 3 Ohm?
Yes GO to AW3 No REPAIR the affected connectors or terminals. Refer to Wiring Diagrams for schematic and connector information. - AW3 CHECK THE FRONT SENSOR GROUND CIRCUIT FOR AN OPEN
- Measure the resistance between:
Positive Lead Measurement / Action Negative Lead C1687-2 Ground
Is the resistance less than 3 Ohm?
Yes GO to AW4 No REPAIR the affected connectors or terminals. Refer to Wiring Diagrams for schematic and connector information. - Measure the resistance between:
- AW4 CHECK THE BRAKE LINING WEAR SENSORS FOR AN OPEN
Is the resistance less than 3 Ohm?
Yes The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. INSPECT all disconnected electrical connectors for corrosion, spread terminals, pushed-out pins, damaged pins or bent pins. REPAIR as necessary. Refer to Connector Repair Procedures for schematic and connector information. No Install a new brake lining wear indicator or indicators as necessary. REFER to: Brake Pads - Electric Motor (C0) . REFER to: Brake Pads - Vehicles With: Electronic Parking Brake (EPB) . REFER to: Brake Pads - Vehicles With: 2-Piston Brake Caliper . REFER to: Brake Pads - 5 Ton Vehicle, Vehicles With: Drum-in-Hat .