Brake System Indicator Circuit Troubleshooting

Brake system indicator does not come on
1. Disconnect the multiplex control unit 13P (underdash fuse/relay box Y) connector and the ABS control unit 47P connector.





2. Check for continuity between the ABS control unit 47P connector terminal No. 13 and body ground.
Is there continuity?
YES - Repair short to body ground in the wire between the multiplex control unit and the ABS modulator-control unit.
NO - Do the multiplex control system troubleshooting.

Brake system indicator does not go off, and no DTCs are stored
1. Release the parking brake.
2. Turn the ignition switch ON (II).
Does the brake system indicator go off after several seconds?
YES - The system is OK at this time.
NO - Go to step 3.
3. Check the brake fluid level.
Is the level OK?
YES - Go to step 4.
NO - Refill the brake fluid, and recheck.
4. Check the ABS indicator.
Does the ABS indicator stay on?
YES - Read the ABS DTC, and do the applicable troubleshooting for the DTC.
NO - Go to step 5.
5. Turn the ignition switch OFF.
6. Disconnect the ABS control unit 47P connector.
7. Turn the ignition switch ON (II).





8. Connect the ABS control unit 47P connector terminal No. 13 and body ground with a jumper wire.
Does the brake system indicator go off?
YES - Check for loose terminal at the ABS control unit 47P connector and G202. If the terminals and ground are OK, replace the ABS modulator-control unit.
NO - Go to step 9.





9. Connect multiplex control unit 13P (under-dash fuse/relay box Y) connector terminal No. 1 and body ground with a jumper wire.
Does the brake system indicator go off?
YES - Repair open in the wire between the multiplex control unit and the ABS modulator control unit.
NO - Do the multiplex control system troubleshooting.