B1476 – IG1 Power supply circuit system (Fuse No.40 circuit), B1477 – IG1 power supply circuit system (Fuse No.37 circuit) MMC Colt



OPERATION

  • The SRS-ECU is powered from the ignition switch (IG1).
  • The SRS-ECU power is supplied from two circuits. Even if one circuit is shut off, the air bag can inflate.

  • DIAGNOSIS CODE SET CONDITIONS


    PROBABLE CAUSES

  • Damaged wiring harnesses or connectors
  • Malfunction of the SRS-ECU

  • DIAGNOSIS PROCEDURE

    STEP 1. M.U.T.-III CAN bus diagnostics.

    Q. Is the CAN bus line found to be normal?

    STEP 2.Check whether the diagnosis code is reset.

    Q. Is the diagnosis code set?

    STEP 3. Check junction block fuse number 40 (diagnosis code B1476) or 37 (diagnosis code B1477).

    Q. Is the fuse burned out?

    STEP 4. Voltage measurement at the SRS-ECU connector B-109.

    Q. Is the check result normal?

    STEP 5. Check a burned-out fuse.

    Q. Is the fuse in good condition?

    STEP 6. Resistance measurement at the junction block connector B-231.

    Q. Is the check result normal?

    STEP 7. Check whether the diagnosis code is reset.

    Q. Is diagnosis code B1476 or diagnosis code B1477 set?



    OPERATION

  • The SRS-ECU is powered from the ignition switch (IG1).
  • The SRS-ECU power is supplied from two circuits. Even if one circuit is shut off, the air bag can inflate.

  • DIAGNOSIS CODE SET CONDITIONS


    PROBABLE CAUSES

  • Damaged wiring harnesses or connectors
  • Malfunction of the SRS-ECU

  • DIAGNOSIS PROCEDURE

    STEP 1. M.U.T.-III CAN bus diagnostics.

    Q. Is the CAN bus line found to be normal?

    STEP 2.Check whether the diagnosis code is reset.

    Q. Is the diagnosis code set?

    STEP 3. Check junction block fuse number 40 (diagnosis code B1476) or 37 (diagnosis code B1477).

    Q. Is the fuse burned out?

    STEP 4. Voltage measurement at the SRS-ECU connector B-109.

    Q. Is the check result normal?

    STEP 5. Check a burned-out fuse.

    Q. Is the fuse in good condition?

    STEP 6. Resistance measurement at the junction block connector B-231.

    Q. Is the check result normal?

    STEP 7. Check whether the diagnosis code is reset.

    Q. Is diagnosis code B1476 or diagnosis code B1477 set?

    Author: admin