Absence of Yellow bus CAN communication (CAN1 buffer overflow)
• Check connector for yellow CAN-bus on BCI (pin A12 and A9). • Check wiring for yellow CAN-bus: - Measure the resistance (with the battery disconnected) between CAN-high (pin A12) and CAN-low (pin A9). 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 A12) and CAN-high on any other unit on the yellow CAN-bus. It should be close to zero ohm. - Measure the resistance (with the battery disconnected) between CAN-low on BCI (pin A9) and CAN-low on any other unit on the yellow 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 yellow CAN-bus from BCI might be degraded. Examples listed below. - brake lights (will be active continuously) - fuel level gauge in instrument cluster
Diagnostic depth
Communication error. Yellow CAN-bus buffer overflow. The yellow CAN-bus has an open circuit.
• Defect connectors on BCI for yellow CAN-bus (pin A12 or A9). • Defect wiring for yellow CAN-bus, open circuit on CAN-high (pin A12) or CAN-low (pin A9). • Ignition signal (pin A11) on BCI is short circuit to supply.