BCM Signal Circuit Inspection

Check CAN high communication circuit
1. Ignition "ON" and Engine "OFF"
2. Connect scantool and select VEHICLE SCOPEMETER function.
3. Measure waveform between "CAN high" of BCM connector and chassis ground.
  Specification : If CAN high communication waveform is displayed, it is OK.
4. Is CAN high communication waveform displayed within specification?
  YES:
  - Go to " 2Check CAN low communication circuit" as below.
  NO:
  - Repair the short to ground or battery in the CAN communication circuit and go to "VERIFICATION OF VEHICLE REPAIR ".
Check CAN low communication circuit
1. Ignition "ON" and Engine "OFF"
2. Connect scantool and select VEHICLE SCOPEMETER function.
3. Measure waveform between "CAN Low" of BCM connector and chassis ground.
  Specification : If CAN low communication waveform is displayed, it is OK.
4. Is CAN communication waveform displayed within specification?
  YES:
  - Go to "COMPONENT INSPECTION " procedure.
  NO:
  - Repair the short to ground or battery or CAN high communication circuit and go to "VERIFICATION OF VEHICLE REPAIR ".