CAN Communication Line Check

WARNING: This page is about a different variant/trim than selected.

■ CAN Communication Circuit Inspection (ECM A.A.F)

Ignition "OFF"
Disconnect A.A.F connector and ECM connector.
Measure the resistance between CAN-HIGH Terminal of A.A.F harness connector and CAN-HIGH terminal of ECM harness connector.
Measure the resistance between CAN-LOW Terminal of A.A.F harness connector and CAN-LOW terminal of ECM harness connector.
Specification : below 1 Ω

Fig 1: A.A.F Connector Circuit Diagram
Courtesy of HYUNDAI MOTOR AMERICA

Fig 2: BMS Connector Terminals
Courtesy of HYUNDAI MOTOR AMERICA
Is the measured resistance within specification?
YES
- Check ECM, 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.

■ Check Short to Ground in CAN Communication Line

IG KEY OFF.
Measure resistance between CAN High Terminal (# 3) of diagnostic connector and chassis ground.
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
Is the measured value within specification?
YES
- Check ECM, 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
- Substitute with a known-good "PCM, BMS" and check for proper operation. If the problem is corrected, replace "PCM, BMS" and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.