Antilock Braking System (ABS)

Circuit Description

A DTC 81 relates to the BPMV not seeing the brake switch signal from start up until 10 seconds after the vehicle reaches speeds over 35 mph An indication of an open brake switch circuit is the ANTILOCK lamp will turn on during acceleration at 15 mph and turn off during deceleration at 15 mph. A faulty brake switch or circuit condition in CKT 420 can cause this DTC. Do not replace the BPMV for this DTC. A faulty BPMV will not cause this DTC to set.

Test Description

- Check for a blown BRAKE fuse
- Check brake switch status using the Tech 1.
- Check CKT 420 for looseness or corrosion.

Diagnostic Aids

Do not replace the BPMV for this DIC. A faulty BPMV will not cause this DTC to set.

This DTC could be caused by the driver riding the brake pedal.

This DTC is a soft fault. The ANTILOCK lamp will not come on until the vehicle reaches 15 mph.

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.