Description

Communication on the CAN bus is disturbed due to ´CAN warning´ conditions.

A ´CAN warning´ is caused by a CAN controller receiving too many invalid data. A CAN controller in warning condition can still read data from the CAN bus but it can no longer send data. The warning condition is automatically cancelled once the CAN controller has received a certain percentage of valid data.

Effects on the driving operation

Transmission shifts sporadically to neutral.

Lighting of the gear range selector becomes dark.

Possible causes

CAN bus incorrectly terminated (bus terminating resistor).

There is a cable break, loose contact or too high contact resistance in the CAN cabling.

Place of action

No description available.

Instruction

Check the cabling (cable break, loose contact, high contact resistance).

Measure between CAN-H and CAN-L: the resistance must be approx. 60 ohms - install / repair bus terminating resistor if necessary.

Setting conditions of the event

No description available.

Testing conditions of the event

No description available.

Final function check

If the defective component cannot be clearly identified, you should try to reproduce the fault:

• Reinstall the component in the vehicle.
• Test function.

After the fault has been eliminated, the following steps have to be carried out:

• Conduct a test drive with function check.
• Read the fault memory
• Check transmission for leaks.
• Perform a final visual inspection.

These steps are necessary to ensure the entire vehicle functions correctly.