U0402

U0402

Diagnosis information - CAN

Fault entry in specified control module

NOTE:
- Internal function test completed.

Diagnostic conditions
The control module initially tests internal function sequences after wake-up. If they are OK, all diagnosable outputs are then tested and any faults are stored.

Control module wake-up through:
- event-induced CAN message
- wake-up signal via wake-up line
- key contact (terminal S)
- "Ignition on"

Possible fault causes
- Control module is incorrectly coded
- Periphery connected to specified control module is incorrect
- Control module faulty (in most cases the cause is not the control module but incorrect coding.)

Fault effects
- The specified control module sends only substitute values via the CAN.
- Other control modules detect these substitute values and set this fault code.