W/Harness Inspection

Terminal and Connector Inspection

1. Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found ?
YES
1) Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
1) Verify presence of battery voltage codes in other ECUs (SRS, etc).
2) If battery voltage codes are not present in other ECUs, go to "Power Circuit Inspection" procedure.
3) If battery voltage codes are present in other ECUs, go to "Alternator Output Voltage Inspection" procedure.

Alternator Output Voltage Inspection

1. Engine "ON".
2. Measure voltage between the battery terminal (+) and the battery terminal (-) with maintaining ENG RPM 2,500 RPM
over 2 minutes.
A. Specification : Below. 17.0V




3. Is the measured voltage within specifications ?
YES
1) Go to "Power Circuit Inspection" procedure.
NO
1) Check that the tension of drive belt, ENG RPM, fuse, terminal of battery, all terminals of alternator are in good condition and Check for damaged harness and poor connection between alternator and battery.
If OK repair or replace alternator and then go to "Verification of vehicle Repair" procedure.

Power Supply Circuit Inspection

1. Engine "ON".
2. Measure voltage between the battery terminal (+) and terminal "4" of the HECU harness connector.
A. Specification : Approx. below 0.2V




3. Is the measured voltage within specifications ?
YES
1) Go to "Ground Circuit Inspection" procedure.
NO
1) Check for damaged harness and poor connection between the battery terminal (+) and terminal "4" of the HECU harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure.

Ground Circuit inspection

1. Ignition "OFF".
2. Disconnect HECU connector.
3. Measure resistance between terminal "8, 24" of the HECU harness connector and chassis ground.
A. Specification : Approx. below 1 ohm




4. Is the measured resistance within specifications ?
YES
1) Substitute with a known-good HECU and check for proper operation. If problem is corrected, replace HECU and then go to "Verification of Vehicle Repair" procedure.
NO
1) Check for damaged harness and poor connection between terminal "8, 24" of the HECU harness connector and chassis ground. Repair as necessary and then go to "Verification of vehicle Repair" procedure.