DTC C1446 [DSC]

id040220803400

DTC

C1446

Brake switch

DETECTION CONDITION

• Brake switch ON signal is input for 6 min or more when driving at a vehicle speed of 20 km/h {12.4 mph} or more.
• Brake switch ON signal is not input even though the DSC HU/CM determines vehicle deceleration.

POSSIBLE CAUSE

• Open or short circuit in the wiring harness between brake switch and the terminal on the PJB
• Open or short circuit in the wiring harness between the terminals on the PJB and PCM
• Brake switch 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:
- PCM (ZY): 1V-Body ground

Voltage

Brake pedal depressed: B+

Brake pedal released:

1 V or less

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 terminals (vehicle harness-side) and brake switch terminal D:
- PCM (ZY): 1V
• 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.
• Start the engine and drive the vehicle at 20 km/h {12.4 mph} or more.
• Are the same DTCs present?
Yes
Repeat the inspection from Step 1.
If the malfunction recurs, replace the DSC 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.
(See DTC Table.)
No
DTC troubleshooting completed.