Code No. C1102: Starter interlock circuit


OPERATION



  • At the auto stop, the ASC-ECU connector terminal TXEG sends brake hold signal to the AS&G-ECU connector terminal TXEG by turning "ON" the power transistor in the unit.

FUNCTION



  • The AS&G-ECU monitors the status of the CAN communication brake hold signal.

TROUBLE JUDGMENT


Check Condition
  • More than 2 seconds have passed since the ignition is switched "ON" or more than 2 seconds have passed since engine starting sequence was completed.
  • Battery voltage is 9 V or more.
  • Code No. U0121: ASC-ECU time-out is not detected.
Judgement Criterion
  • For 2 seconds, the brake hold signal (CAN) value is "ON" and the brake hold signal (signal line) is "OFF".


  • For 2 seconds, the brake hold signal (CAN) value is "OFF" and the brake hold signal (signal line) is "ON".

FAIL-SAFE AND BACKUP FUNCTION



  • In the normal operation, the auto stop is prohibited.
  • If the malfunction is detected during the auto stop, the auto start is prohibited.

PROBABLE CAUSES



  • Open/short circuit or damage in brake hold signal circuit or loose connector contact
  • Failed ASC-ECU
  • Failed AS&G-ECU

DIAGNOSIS PROCEDURE

STEP 1. Perform voltage measurement at ASC-ECU connector.

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

Q. Is the check result normal?
Go to Step 4.
Go to Step 2.

STEP 2. Check of short to earth and open circuit in TXEG line between ASC-ECU connector and AS&G-ECU connector


Q. Is the check result normal?
Go to Step 3.
Repair the connector(s) or wiring harness.

STEP 3. 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 4. Check of harness damage in TXEG line between ASC-ECU connector and AS&G-ECU connector


Q. Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.

STEP 5. M.U.T.-III data list



  • Disconnect A-58 ASC-ECU connector.
  • Ignition switch: ON
  • Item 28: Brake hold signal (H/W)
OK: OFF

Q. Is the check result normal?
Go to Step 6.
Go to Step 3.

STEP 6. M.U.T.-III data list



  • Ignition switch: ON
  • Item 28: Brake hold signal (H/W)
OK: OFF

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions).
Replace the ASC-ECU.