Electrical Error on canbus 4
• Measure the resistance (with the battery disconnected) between CAN-high (pin B5) and CAN-low (pin B14). It should be close to 60 ohm (one 120 ohm termination resistor in each end of the CAN-bus). • Measure the resistance (with the battery disconnected) between CAN-high (pin B5) and supply. It should be high ohmic (Mega ohm). • Measure the resistance (with the battery disconnected) between CAN-high (pin B5) and ground. It should be high ohmic (Mega ohm). • Measure the resistance (with the battery disconnected) between CAN-low (pin B14) and supply. It should be high ohmic (Mega ohm). • Measure the resistance (with the battery disconnected) between CAN-low (pin B14) and ground. It should be high ohmic (Mega ohm). • Disconnect one ECU unit at a time from the CAN bus and check if the fault disappears. • Check connector pins • Check cabling • Check connectors for all ECU:s on the indicated bus. Check for verdigris, broken, unconnected or shorted pins. Disconnect one ecu at a time.
What you'll see
No driver-visible symptom recorded.
System reaction
• Several warnings are active in the instrument cluster. • Functions dependent on information from CAN bus 4 are degraded, such as: - Adaptive Cruise Control - Lane Departure Warning - Blind Spot Warning
Diagnostic depth
The DTC is set to active if no messages are received according to the current configuration. Only messages with attached timeout error codes are tested. The DTC is set to inactive if a message is received. The DTC is not validated (stored) if: • the ignition is turned off • first 2 seconds after ignition on • the supply voltage is below 22 volt • the supply voltage is above 30 volt
Defect wiring of CAN-bus: - CAN-high wire open load - CAN-low wire open load - CAN-high and CAN-low open load at the same location - Loss of connection to termination network - Short circuit between CAN-high and CAN low. - Short circuit between CAN-high and supply voltage. - Short circuit between CAN-high and ground. - Short circuit between CAN-low and supply voltage. - Short circuit between CAN-low and ground. • Defect ECU unit(s)on the CAN-bus. • ECU unit(s) on the CAN-bus communicates with 250 kb/s.