Code No. B1353: DC/DC Converter (Control System) Control Circuit




OPERATION




FUNCTION




TROUBLE JUDGMENT


Check Condition
Judgement Criterion
or

or


FAIL-SAFE AND BACKUP FUNCTION




PROBABLE CAUSES




DIAGNOSIS PROCEDURE


STEP 1. Perform voltage measurement at AS&G-ECU connector.



  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal DCCP and earth.
OK: System voltage

Q. Is the check result normal?

Go to Step 3.
Go to Step 2.

STEP 2. Check of short to earth and open circuit in DCCP line between DC/DC converter (control system) connector and AS&G-ECU connector.



  • Check output line for open/short circuit.

Q. Is the check result normal?

Replace the DC/DC converter (control system).
Repair the connector(s) or wiring harness.

STEP 3. Perform voltage measurement at AS&G-ECU connector.



  • Measure the voltage AS&G-ECU connector terminal.
  • Ignition switch: ON
  • Voltage between terminal DCCP and earth.
OK: Voltage is 25% of the battery voltage or less.

Q. Is the check result normal?

Go to Step 5.
Go to Step 4.

STEP 4. M.U.T.-III diagnosis code



  • Reconfirmation of the diagnosis code.

Q. Is the diagnosis code set?

Replace the AS&G-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions).

STEP 5. Check of harness damage in DCCP line between DC/DC converter (control system) connector and AS&G-ECU connector



  • Check output line for damage.

Q. Is the check result normal?

Go to Step 6.
Repair the connector(s) or wiring harness.

STEP 6. M.U.T.-III diagnosis code



  • Reconfirmation of the diagnosis code.

Q. Is the diagnosis code set?

Replace the AS&G-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions).