Antilock Braking System (ABS) - Rear Wheel Antilock Brakes (RWAL)

Stop Lamp Switch Schematic:

Diagnostic Trouble Code (DTC) 10, Stop Lamp Circuit:

CIRCUIT DESCRIPTION
A Diagnostic Trouble Code (DTC) 10 relates to the 12 volt signal in the stop lamp switch circuit. The Electronic Brake Control Module (EBCM) uses this circuit to prepare for a possible anti lock stop. The stop lamp switch closes when the brake pedal is released sending 12 volts to terminal F of the EBCM. Applying the brake pedal causes this signal to drop to less than 1 volt. When the EBCM sees this drop it gets ready to control the anti lock pressure valve if necessary.

TEST DESCRIPTION
- Check if voltage is available at the stop lamp switch.
- Check if voltage is getting through the stop lamp switch with the brake pedal released.
- Check if voltage is reaching terminal F and ground potential is available at terminal A.
- Check the operation of the stop lamp switch during actual driving conditions. This helps determine if the DTC is intermittent.

DIAGNOSTIC AIDS
Do not replace the EBCM or Antilock Pressure Valve (APV) for this DTC. An EBCM or APV malfunction will not cause this DTC to set.

This DTC is set when the vehicle speed reaches 35 mph or greater and there is no 12 volt signal from the stop lamp switch.

This DTC is a soft fault that turns on the BRAKE lamp until 12 volts is received from the stop lamp switch.

CAUTION: Do not pierce the electrical connectors, wires, seals, or insulation during testing. Doing so will break the seal and lead to corrosion and failure of the wiring and terminals.