DTC C1446 [DSC/RSC]


id0402b3803400

DTC
C1446
Brake switch system
DETECTION CONDITION
•  Brake switch ON signal is not input when the brake fluid pressure sensor signal reaches the specified value.
•  Brake switch ON signal is input even if the signal from the brake fluid pressure sensor is less than the specification.
POSSIBLE CAUSE
•  Open or short circuit in wiring harness between the brake switch and PCM 1T terminal (PCM CONNECTOR (2 TYPES))
•  Open or short circuit in wiring harness between the brake switch and PCM 1S terminal (PCM CONNECTOR (3 TYPES))
•  Brake switch malfunction
•  DSC/RSC HU/CM malfunction
•  Poor connection at connectors (female terminal)

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY OPEN OR SHORT CIRCUIT IN BRAKE SWITCH SIGNAL
•  Turn the ignition switch to the ON position.
•  Measure the voltage between the following PCM terminals and body ground when the brake pedal is depressed and released:
―  1T (PCM CONNECTOR (2 TYPES))
―  1S (PCM CONNECTOR (3 TYPES))
Voltage
Brake pedal depressed: B+
Brake pedal released: 1 V or less
•  Is the voltage normal?
Yes
Go to Step 5.
No
If it is B+ under any condition, then go to the next step.
If it is 1 V or less under any condition, then go to Step 3.
2
INSPECT BRAKE SWITCH SIGNAL FOR SHORT TO POWER SUPPLY CIRCUIT
•  Disconnect the brake switch connector.
•  Measure the voltage between the brake switch connector terminal D (vehicle harness-side) and body ground.
•  Is the voltage 1 V or less?
Yes
Go to Step 4.
No
Repair or replace the wiring harness between the PCM and brake switch, then go to Step 5
3
INSPECT BRAKE SWITCH SIGNAL FOR OPEN CIRCUIT
•  Disconnect the PCM connectors.
•  Disconnect the brake switch connector.
•  Inspect continuity between the following PCM connector terminal (vehicle harness-side) and brake switch terminal D:
―  1T (PCM CONNECTOR (2 TYPES))
―  1S (PCM CONNECTOR (3 TYPES))
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness between the PCM and brake switch, then go to Step 5.
4
INSPECT BRAKE SWITCH
•  Inspect the brake switch.
•  Is the brake switch normal?
Yes
Go to the next step.
No
Replace the brake switch, then go to the next step.
5
VERIFY THAT THE SAME DTC IS NOT PRESENT
•  Reconnect all disconnected connectors.
•  Clear the DTCs from the memory.
•  Are the same DTCs present?
Yes
Repeat the inspection from Step 1.
If the malfunction recurs, replace the DSC/RSC HU/CM, then go to the next step.
No
Go to the next step.
6
VERIFY THAT NO OTHER DTCS ARE PRESENT
•  Are any other DTCs output?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.