What does it mean?
C1185 is a Chassis (ABS, traction control, steering) fault code. It indicates: ICC Unit .
Symptoms
- Cruise control cannot be switched on, or it switches itself off shortly after being set
- A cruise control or driver assistance warning lamp and a text message appear on the display
- ABS or stability control lamps may come on alongside the assistance warning
- Forward collision warning, automatic braking and distance keeping functions become unavailable
- The system often works normally in clear weather and fails in heavy rain, fog or snow, which points at the sensor face rather than the unit
Likely causes
- Internal fault in the ICC unit itself
- Radar or laser sensor face blocked by dirt, snow, ice, a badge, a plate frame or a bumper repair
- Sensor knocked out of alignment after a minor front end impact, towing eye use or bumper removal
- Radar alignment not carried out after the unit, bumper or front panel was replaced
- Damaged or corroded connector at the unit, or chafed wiring behind the front bumper
- Communication fault between the ICC unit and the ABS, stability or engine control modules on the data bus
- Blown fuse or low system voltage causing the unit to drop offline
How to fix it
- Clean the sensor face and the bumper area in front of it, and remove any added badge, plate frame, film or spoiler that sits in the beam path
- Scan every module and note communication and stability control codes; a bus fault will disable the assistance system without the unit being faulty
- Check the fuses for the driver assistance system and measure supply voltage and ground at the unit
- Inspect the connector and the harness behind the bumper for water, corrosion, chafe and damage from previous body repair
- Ask about any recent front end repair, bumper removal or windscreen replacement, then check that the unit sits square on its mounts
- Perform the radar or camera alignment procedure with the correct targets and a level surface
- Replace the ICC unit only after alignment, wiring and communication checks have all been completed, and align it again afterwards