B1728, B1729 – Abnormal voltage at ETACS-ECU power supply MMC Colt

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COMMENTS ON TROUBLE SYMPTOM

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PROBABLE CAUSES

Malfunction of the ETACS-ECU

Malfunction of battery

Malfunction of alternator

Damaged the wiring harness or connectors

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DIAGNOSIS PROCEDURE

STEP 1. Power supply fuse check

Q. Is the fuse in good condition?

STEP 2. Battery check

Q. Is the battery in good condition?

STEP 3. Charging system check

Q. Is the charging system in good condition?

STEP 4. M.U.T.-III data list

Q. Is the check result normal?

STEP 5. Connector check: B-234 ETACS-ECU connector

Q. Is the check result normal?

STEP 6. Check the wiring harness between B-234 ETACS-ECU connector terminal No.20 and the fusible link (1).

Check the power supply line from the fusible link (1) for open circuit.

Q. Is the check result normal?

STEP 7. Connector check: B-233 ETACS-ECU connector

Q. Is the check result normal?

STEP 8. Check the wiring harness between B-233 ETACS-ECU connector terminal No.52 and the ignition switch (IG1).

Check the power supply line to the ignition switch (IG1) for open circuit.

Q. Is the check result normal?

STEP 9. Check whether the diagnosis code is reset.

Q. Is the diagnosis code set?