Absence of CAN communication or electrical error on Expansion CAN-bus.
• Check connector for expansion CAN-bus on BCI (pin C11 and C12). • Check wiring for expansion CAN-bus: - Measure the resistance (with the battery disconnected) between CAN-high (pin 32) and CAN-low (pin 35). 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 on BCI (pin C11) and CAN-high on any other unit on the expansion CAN-bus. It should be close to zero ohm. - Measure the resistance (with the battery disconnected) between CAN-low on BCI (pin C12) and CAN-low on any other unit on the expansion CAN-bus. It should be close to zero ohm. • Check wiring and connector for the ignition signal (pin 38).
What you'll see
No driver-visible symptom recorded.
System reaction
• Functions dependent on information on the expansion CAN-bus from BCI might be degraded.
Diagnostic depth
The fault is validated as present if the ECU tries to send CAN-messages on the expansion CAN-bus, but no acknowledge is received from other units, and thereby causing the internal send buffer (in the ECU) to overflow. The DTC is set to active if the buffer overflow has lasted for 50 ms. The DTC is set to inactive when the CAN-messages are sent properly again and the buffer no longer is overflowing for the last 1050 ms. The DTC is not validated (stored) if: • short circuit on expansion CAN-bus (separate DTC)
• Defect connectors on BCI for expansion CAN-bus. • Defect wiring for expansion CAN-bus, open circuit on CAN-high or CAN-low. • Ignition signal on BCI is short circuit to supply.