Code No. B1354: DC/DC converter (Entertainment System) Control Circuit




OPERATION




FUNCTION




TROUBLE JUDGMENT


Check Condition
Judgement Criterion
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 DCCT 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 DCCT line between DC/DC converter (entertainment system) connector and AS&G-ECU connector.


Q. Is the check result normal?

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

STEP 3. Perform voltage measurement at C-64 AS&G-ECU connector.



  • Measure the voltage AS&G-ECU connector terminal.
  • Ignition switch: ON
  • Voltage between terminal DCCT 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. Perform voltage measurement at AS&G-ECU connector



  • Measure the voltage AS&G-ECU connector terminal.

  • Perform auto start with the following procedures.

  1. Change vehicle status to auto stop status.
  2. Selector lever: D range → P range
  3. Release the brake pedal then depress it again (Auto Start carried out at this point).

  • Voltage between terminal DCCP and earth.
OK: Voltage is 75% of the battery voltage or more.

Q. Is the check result normal?

Go to Step 7.
Go to Step 6.

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).

STEP 7. Check of harness damage in DCCT line between AS&G-ECU connector and DC/DC converter (entertainment system) connector


Q. Is the check result normal?

Go to Step 8.
Repair the connector(s) or wiring harness.

STEP 8. 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).