CAN Communication Line Inspection

■ CAN Communication Circuit Inspection (HCU ↔ A.A.F) 

1. Ignition "OFF"
2. Disconnect A.A.F connector and HCU connector.
3. Measure the resistance between CAN-HIGH Terminal of A.A.F harness connector and CAN-HIGH terminal of HCU harness connector.
4. Measure the resistance between CAN-LOW Terminal of A.A.F harness connector and CAN-LOW terminal of HCU harness connector.

   Specification  : below 1 Ω

   Fig 1: PCM Circuit Diagrams

   Courtesy of HYUNDAI MOTOR AMERICA
   Fig 2: PCM Connector Terminals

   Courtesy of HYUNDAI MOTOR AMERICA
5. Is the measured resistance within specification?

   YES 

   • Check HCU, A.A.F connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Check for open/short in harness.

     Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

■ Check Short to Ground in CAN Communication Line 

1. IG KEY OFF.
2. Measure resistance between CAN High Terminal (# 3) of diagnostic connector and chassis ground.
3. Measure resistance between CAN Low Terminal (# 11) of diagnostic connector and chassis ground.

   Specification  : ∞ Ω

   Fig 3: PCM Circuit Diagram

   Courtesy of HYUNDAI MOTOR AMERICA
   Fig 4: BMS Connector Terminals

   Courtesy of HYUNDAI MOTOR AMERICA
4. Is the measured value within specification?

   YES 

   • Check HCU, A.A.F connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO 

   • Check short to ground in communication line. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.