Absence of development bus CAN communication (CAN2 buffer overflow)
• Check connector for external CAN-bus on BCI (pin <TBD> and <TBD>). • Check wiring for external CAN-bus: - Measure the resistance (with the battery disconnected) between CAN-high (pin TBD) and CAN-low (pin TBD). 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 TBD) 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 TBD) 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 TBD) on the TBD.
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. Examples listed below. - TBD <--- DENNA MÅSTE SES ÖVER!!! - TBD <--- DENNA MÅSTE SES ÖVER!!!
Diagnostic depth
The fault is validated as present if the ECU tries to send CAN-messages on the external 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: • 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 • short circuit on external CAN-bus (separate DTC)
• Defect connectors on BCI for external CAN-bus (pin TBD or TBD). • Defect wiring for external CAN-bus, open circuit on CAN-high (pin TBD) or CAN-low (pin TBD). • Ignition signal (pin TBD) on BCI is short circuit to supply.