Code No.C1422, C1423: Power Supply Voltage System












OPERATION



DIAGNOSIS CODE SET CONDITIONS



  • When power supply voltage drops to 9.5 V or less, the code No.C1422 is set as low voltage.
  • When power supply voltage rises to 18 V or more, the code No.C1423 is set as high voltage.

PROBABLE CAUSES



  • Malfunction of the ignition switch
  • Damaged harness wires and connectors
  • Malfunction of the transfer-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list
Item 20: Ignition voltage (Refer to data list reference table ).

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Go to Step 2.

STEP 2. Measure the voltage at transfer-ECU connector D-124.
(1)Disconnect the connector, and measure the voltage between terminal No.25 and earth at the wiring harness side.
(2)Turn the ignition switch to the ON position.
OK: System voltage

Q. Is the check result normal?
Go to Step 5.
Go to Step 3.

STEP 3. Connector check: D-401 J/B connector, D-225, D-229 intermediate connector, D-124 transfer-ECU connector.
Check for the contact with terminals.

Q. Is the check result normal
Go to Step 4.
Repair the defective connector.

STEP 4. Check the harness between J/B connector D-401 terminal No.12 and transfer-ECU connector D-124 terminal No.25.
Check the power supply line for short or open circuit.

Q. Is the check result normal?
Go to Step 6.
Repair the wiring harness.

STEP 5. Connector check: D-124 transfer-ECU connector.
Check for the contact with terminals.

Q. Is the check result normal?
Go to Step 6.
Repair the defective connector.

STEP 6. M.U.T.-III data list
Item 20: Ignition voltage (Refer to data list reference table ).

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
Replace the transfer-ECU.