Instruments - Adaptive Cruise Control Inop. and DTC C110BF0
91 ACC and braking guard warning message (DTC C110BF0)91 13 78
2033355/1
March 15, 2013
Vehicle Information
Condition
^ Adaptive Cruise Control (ACC) does not work.
^ The message "ACC and braking guard: unavailable at this time. No sensor vision" appears in the instrument cluster.
^ The following DTC is logged in the distance regulation control module, J428 (address word 13):
C110BF0 (Adaptive cruise control sensor Restricted view)
Technical Background
ACC is deactivated when either of the two radar sensors does not detect any objects for an extended duration. The most common cause for this type of deactivation is that the field of vision of the radar sensor(s) is blocked; however, any of the following conditions could cause the ACC to temporarily switch off:
^ Leaves, snow, strong water spray, or dirt in the field of vision of either of the radar sensors. This is mainly related to poor weather conditions. The ACC can also be switched off in dry weather conditions if the radar sensor is covered by salt, dirt, or other debris.
^ The radar sensors can be pulled out of their plastic mounting clips in a minor collision which produces no visible external damage. This type of impact may distort the sensor viewing angle enough to create a limited view condition.
^ When the vehicle is driven through a long tunnel, the reflection off the walls to the radar sensors can lead to ACC deactivation.
^ When the vehicle is driven on desolate roads, the sensors do not receive reflected signals for an extended time (other vehicle traffic is not detected in the sensor field of vision) which can lead to ACC deactivation.
Production Solution
Not applicable.
Service
^ An ACC shutdown because of dirt or debris is unavoidable and should not be claimed under warranty. Clean the sensors and the system can be reactivated.
^ Minor collisions with no visible exterior damage can damage the plastic mounting clips. Use the available repair kit to replace the mounting clips (see ETKA for part information) and recalibrate the ACC system. Repairs due to outside influence cannot be claimed under warranty.
^ If the ACC system is deactivated during a drive in a long tunnel or when traveling for an extended time without other vehicle traffic in the field of view of the sensors, the system is performing as designed. Please explain to the customer this condition and ensure the customer understands the system is operating as designed.
Avoid any unnecessary replacement of the radar sensors.
Warranty
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.