DTC C1446 [APPLIED VIN (ASSUMED): JM0 DY10Y100 100001-108401, JM6 DY10*100 100001-109000]

id0402a3803400

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 T 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 T (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 T, then go to Step 4.
2
INSPECT BRAKE LIGHT SWITCH SIGNAL CIRCUIT FOR SHORT TO POWER CIRCUIT
• Measure voltage between ABS HU/CM terminal T (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 T, then go to Step 4.
No
Go to next step.
3
INSPECT BRAKE LIGHT SWITCH
• Inspect brake light switch.
• Is it okay?
Yes
Go to next step.
No
Replace brake light switch, then go to next step.
4
VERIFY TROUBLESHOOTING COMPLETED
• Clear DTC from memory.
• 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.