DTC C0023:62/C0040:64 [DSC HU/CM]


id040262906400

DTC

C0023:62

Brake switch

C0040:64

DETECTION CONDITION
•  C0023:62
―  Brake light signal cannot be detected even though brake light signal is requested.
―  Error detected in signal from rear body control module via CAN communication.
•  C0040:64
―  Accelerator pedal is depressed and brake switch on condition continues for 30 to 60 s while vehicle is driven at 10.8 km/h {6.71 mph} or more.
―  A brake switch ON signal is not input when the brake fluid pressure sensor signal reaches the specified value.
FAIL-SAFE FUNCTION
•  Refer to “Fail-safe function table”. (See DTC TABLE [DSC HU/CM].)
POSSIBLE CAUSE
•  Brake switch malfunction
•  Open or short circuit in wiring harness between brake switch terminal D and brake light unit terminal I
•  Open or short circuit in wiring harness between brake light unit terminal H and DSC HU/CM terminal O
•  Brake light unit malfunction
•  Poor connection at each connector
•  DSC HU/CM malfunction

Diagnostic Procedure

Step

Inspection

Action

1
INSPECT BRAKE LIGHT UNIT VOLTAGE
•  Disconnect the brake light unit connector.
•  Measure the voltage between brake light unit terminal I (wiring harness-side) and body ground.
•  Is the voltage within followings?
―  Brake pedal depressed: B+
―  Brake pedal released: 1.0 V or less
Yes
Go to step 4.
No
•  If it is B+ under any condition, then go to the next step.
•  If it is 1.0 V or less under any condition, then go to Step 3.
2
INSPECT BRAKE SWITCH
•  Inspect brake switch.
•  Is the brake switch normal?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between brake switch terminal D and brake light unit terminal I.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power circuit.
Go to step 6.
No
Replace the brake switch, then go to step 6.
3
INSPECT BRAKE SWITCH
•  Inspect brake switch.
•  Is the brake switch normal?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between brake switch terminal D and brake light unit terminal I.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open or short to ground circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open or short to ground circuit.
Go to step 6.
No
Replace the brake switch, then go to step 6.
4
INSPECT WIRING HARNESS BETWEEN BRAKE LIGHT UNIT AND DSC HU/CM FOR OPEN OR SHORT CIRCUIT
•  Disconnect the DSC HU/CM connector.
•  Measure the voltage between DSC HU/CM terminal O (wiring harness-side) and body ground.
•  Is the voltage within followings?
―  Brake pedal depressed: B+
―  Brake pedal released: 1.0 V or less
Yes
Go to the next step.
No
•  If it is B+ under any condition, refer to the wiring diagram and verify whether or not there is a common connector between brake light unit terminal H and DSC HU/CM terminal O.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power circuit.
•  If it is 1.0 V or less under any condition, refer to the wiring diagram and verify whether or not there is a common connector between brake light unit terminal H and DSC HU/CM terminal O.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open or short to ground circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open or short to ground circuit.
•  Go to step 6.
5
INSPECT BRAKE LIGHT UNIT
•  Inspect the brake light unit.
•  Is the brake light unit normal?
Yes
Go to the next step.
No
Replace the brake light unit, then go to the next step.
6
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Using the M-MDS, clear the DTC from the DSC HU/CM.
•  Using the M-MDS, perform the DSC HU/CM DTC inspection.
•  Is the same DTC present?
Yes
If the malfunction recurs, replace the DSC HU/CM, then go to the next step.
No
Go to the next step.
7
VERIFY NO DTC IS PRESENT
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
DTC troubleshooting completed.