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DTC C1446 [APPLIED VIN (ASSUMED): JM0 DY10Y100 108402-, JM6 DY10*100 109001-]

id0402a4803400

DTC | C1446 | Brake light switch
DETECTION CONDITION | • ON signal is input from the brake switch for 6 min or more while the vehicle is driving at a vehicle speed of 20 km/h {12.4 mph} or more. • ON signal is not input from the brake switch though the ABS HU/CM determines that the vehicle is decelerating.
POSSIBLE CAUSE | • Malfunction of brake switch • Open or short circuit in harness between ABS HU/CM terminal V and brake light switch

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | INSPECT BRAKE LIGHT SWITCH SIGNAL CIRCUIT FOR OPEN CIRCUIT • Turn ignition key to OFF. • Disconnect ABS HU/CM connector. • Measure continuity between ABS HU/CM terminal V (harness side) and brake light switch. • Is there continuity? | Yes | Go to next step.
No | Repair or replace harness for open circuit between brake light switch and ABS HU/CM terminal V, then go to Step 4.
2 | INSPECT BRAKE LIGHT SWITCH SIGNAL CIRCUIT FOR SHORT TO POWER CIRCUIT • Measure voltage between ABS HU/CM terminal V (harness side) and ground. • Is voltage B+? | Yes | Repair or replace harness for short to power circuit between brake light switch and ABS HU/CM terminal V, then go to Step 4.
No | Go to next step.
3 | INSPECT BRAKE LIGHT SWITCH • Inspect brake light switch. • Is it normal? | Yes | Go to next step.
No | Replace brake light switch, then go to next step.
4 | VERIFY TROUBLESHOOTING COMPLETED • Clear DTC from memory. (See Clearing DTCs Procedures.) • Start engine and drive vehicle at 10 km/h {6.2 mph} or above. • Gradually slow down and stop vehicle. • Is same DTC present? | Yes | Replace ABS CM, then go to next step.
No | Go to next step.
5 | VERIFY AFTER REPAIR PROCEDURE • Is there any other DTC present? | Yes | Go to applicable DTC inspection.
No | Troubleshooting completed.