Electrical error on CAN-bus 1 (CAN1 BusOff).
• Measure the resistance (with the battery disconnected) between CAN-high (pin B1) and CAN-low (pin B10). 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 B1) and supply. It should be high ohmic (Mega ohm). • Measure the resistance (with the battery disconnected) between CAN-high (pin B1) and ground. It should be high ohmic (Mega ohm). • Measure the resistance (with the battery disconnected) between CAN-low (pin B10) and supply. It should be high ohmic (Mega ohm). • Measure the resistance (with the battery disconnected) between CAN-low (pin B10) 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 other ECUs on this CAN bus, one at a time, and see if status of DTC changes.
What you'll see
No driver-visible symptom recorded.
System reaction
• Several warnings are active in the instrument cluster. • Functions dependent on information on CAN bus 1 are degraded.
Diagnostic depth
The DTC is set to active if CAN controller of the bus is in the state bus-off. The DTC is set to inactive if the CAN-controller is not in state bus-off for 1100 ms. 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 32 volt
• Defect wiring of CAN-bus 1: - CAN-high interrupted - CAN-low interrupted - CAN-high and CAN-low interrupted 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(s) on the CAN-bus. • ECU on the CAN-bus communicates with 500 kbps. • These causes might not be detectable by the CAN controller. Instead timouts will occur for involved ECUs.