DTC C1446 [DSC (MZ-CD 1.6 (Y6))]


B3E040200000W01

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: 317-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 voltage between the brake switch connector terminal B (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 B:
- PCM: 317
• 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 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.
(See DTC Table.)
No
DTC troubleshooting completed.