CAN Signal Circuit Inspection

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

■ Short Check (to ground)

Ignition "OFF" & Engine "OFF".
Disconnect TPMS ECU, PCM and ABS ECU connector.
Measure resistance between CAN LOW terminal, CAN HIGH terminal of the TPMS ECU harness connector and chassis ground.
Specification :

Fig 1: Measuring Resistance Between CAN LOW Terminal And Chassis Ground
Courtesy of HYUNDAI MOTOR AMERICA

Fig 2: Data Link Connector Terminals
Courtesy of HYUNDAI MOTOR AMERICA
Is the measured resistance within specifications?
YES
- Go to next procedure.
NO
- If abnormal resistance is detected in CAN HIGH circuit, Repair short to ground in CAN HIGH circuit and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  If abnormal resistance is detected in CAN LOW circuit, Repair short to ground in CAN LOW circuit and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.

■ CAN BUS Resistance Check

Ignition "OFF" & Engine "OFF".
Disconnect TPMS ECU, PCM and ABS ECU connector.
Measure resistance between CAN LOW terminal and CAN HIGH terminal of the TPMS ECU harness connector.
Specification : Approx. 120

Fig 3: Measuring Resistance Between CAN Low And High Terminal Of TPMS ECU Harness Connector
Courtesy of HYUNDAI MOTOR AMERICA

Fig 4: Data Link Connector Terminals
Courtesy of HYUNDAI MOTOR AMERICA
Is the measured resistance within specifications?
YES
- Go to "COMPONENT INSPECTION " procedure.
NO
- In case of the resistance "approx. 1Ω": Repair mutual short in CAN signal circuit of the TPMS ECU and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  In case of the resistance "∞ Ω": Repair open in CAN signal circuit of the TPMS ECU and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  
  In case of the resistance "approx. 120Ω": Check the resistances (122Ω) in I/P junction box and ECM, repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.