Absence of external bus CAN communication (CAN3 buffer overflow)
• Check connector for external CAN-bus on BCI (pin C14 and C15). • Check wiring for external CAN-bus: - Measure the resistance (with the battery disconnected) between CAN-high (pin C14) and CAN-low (pin C15). 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 C14) and CAN-high on any other unit on the external CAN-bus. It should be close to zero ohm. - Measure the resistance (with the battery disconnected) between CAN-low on BCI (pin C15) and CAN-low on any other unit on the external CAN-bus. It should be close to zero ohm. • Check wiring and connector for the ignition signal (pin A11) on the BCI.
What you'll see
No driver-visible symptom recorded.
System reaction
• Functions dependent on information on the external CAN-bus from BCI might be degraded.
Diagnostic depth
Communication error. External CAN-bus buffer overflow. The external CAN-bus has an open circuit.
• Defect connectors on BCI for external CAN-bus (pin C14 or C15). • Defect wiring for external CAN-bus, open circuit on CAN-high (pin C14) or CAN-low (pin C15). • Ignition signal (pin A11) on BCI is short circuit to supply.