Timeout on messages from the engine control unit on CAN
Check CAN connections, connectors and cable harnesses. Also check the engine control unit.
What you'll see
No driver-visible symptom recorded.
System reaction
For vehicles with an automatic gearbox: The automatic gearbox function may be impaired. For vehicles with retarder: Depending on which CAN messages are missing, the retarder system will work with reduced functionality. The fault can result in: No brake blending (Bad comfort at gear change). That retarder braking via the lever is not cancelled when the driver accelerates. No exhaust brake in conjunction with retarder braking.
Diagnostic depth
Expected CAN messages from the engine control unit are missing.
If both fault codes 11040 and 11041 have been generated, there is probably an open circuit on the CAN connection to the engine control unit.If fault codes 11040, 11041, 11050, 11051 and 11060 have been generated, there is probably an open circuit on the CAN cable to the TMS control unit.