W/Harness Inspection

ABS/ESC(MGH-25)
C1616 CAN bus off - Inspection/Repair:_: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) Go to "Signal Circuit Inspection" procedure.

Signal Circuit Inspection

1. Ignition "OFF".
2. Disconnet the HECU harness connector.
3. Measure resistance between terminal "7" of the HECU harness connector and terminal "22" of the HECU harness connector.
A. Specification : Approx. 60Ohms




4. Is the measured resistance within specifications?
YES
1) Fault is intermittent caused by open or short in CAN signal harness or was repaired and HECU memory was not cleared. go to "CAN Bus Short (to ground) Inspection" procedure.
NO
1) Check for open or short in CAN signal harness between terminal "7" of the HECU harness connector and terminal "22" of the HECU harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure.

CAN Bus Short (to ground) Inspection

1. Ignition "OFF".
2. Disconnet the HECU harness connector.
3. Measure resistance between terminal "7,22" of the HECU harness connector and chassis ground.
A. Specification : Approx. Infinity Ohms




4. Is the measured resistance within specifications?
YES
1) Go to "CAN Bus Short (between HIGH and LOW) Inspection" procedure.
NO
1) Check for short to ground in CAN HIGH signal harness in case of abnormal resistance measured between terminal "7" of the HECU harness connector and chassis ground. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
2) Check for short to ground in CAN LOW signal harness in case of abnormal resistance measured between terminal "22" of the HECU harness connector and chassis ground. Repair as necessary and then go to "Verification of vehicle Repair" procedure.

CAN Bus Short (to battery) Inspection

1. Ignition "OFF".
2. Disconnet the HECU harness connector.
3. Measure voltage between terminal "7,22" of the HECU harness connector and chassis ground.
A. Specification : Below. 0.2 V




4. Is the measured resistance within specifications?
YES
1) Go to "CAN Bus Short (between HIGH and LOW) Inspection" procedure.
NO
1) Check for short to battery in CAN HIGH signal harness in case of abnormal resistance measured between terminal "7" of the HECU harness connector and chassis ground. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
2) Check for short to battery in CAN LOW signal harness in case of abnormal resistance measured between terminal "22" of the HECU harness connector and chassis ground. Repair as necessary and then go to "Verification of vehicle Repair" procedure.

CAN Bus Short (between HIGH and LOW) Inspection

1. Ignition "OFF".
2. Disconnet all the connetor related to CAN such as HECU, PCM, EPS, ECS harness connector.
3. Measure resistance between terminal "7,22" of the HECU harness.
A. Specification : Approx. 120 Ohms




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 short in CAN signal harness between terminal "7" of the HECU harness connector and terminal "22" of the HECU harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure.