CD8B

CD8B - U1139

Information saved in
DME

Fault code
CD8B - U1139

Fault text
Bus Off idel-controller CAN

Fault description
Idle-Speed Control Valve / AMT Communication Bus Off

Condition for fault identification
Test condition:
Bus-off from CAN driver
Terminal condition: Wakeup
Voltage condition:
UBatt, u_wakeup > 9V (k_smg_can_ed_ub_min)

Condition for fault memory entry
150 ms

Action in service
1. Clear fault memory, LLS idle actuator system test,
2. Check wiring harness at LLS1 and LLS2, check SMG
ECU and DME,
3. Disconnect SMG ECU, clear fault memory, perform LLS
idle actuator system test
4. Disconnect LLS individually and clear fault memory,
perform LLS system test

Fault effect and breakdown warning
DSC lamp/ CC message/power reduction/high
idle/displayed rpm limit at 2500 rpm/poor throttle response/
MIL after engine runs 2x

Driver information
Warning light:
MIL, EML, CC message, backup program

Service instruction
none