Adaptive Cruise Control (ACC) Symptom Troubleshooting Index
NOTE: The ACC system is cancelled when the VSA system is activated.

Symptom
Diagnostic procedure
Also check for
Vehicle speed can be set, but there is no ACC indication on the MID
Do the gauge control module self-diagnostic function procedure.
  
ACC OFF is displayed on the MID unexpectedly
Check the ACC system auto stop control history.
  
Vehicle speed cannot be set when the SET switch is pressed between the 25 mph (40 km/h) and 90 mph (145 km/h)
An open in the wire
A short in the wire
The system is in service mode
Vehicle does not decelerate or accelerate accordingly when the SET or RES switch is pressed
Test the ACC combination switch.
An open in the wire
Set speed does not cancel when the brake pedal is pressed
Test the brake pedal position switch.
An open in the wire
Set speed does not cancel when the MAIN switch is turned off
Test the ACC combination switch.
An open in the wire
Set distance cannot be adjusted with the distance switch
Test the distance switch.
  
Vehicle speed can be set, but vehicle decelerates
Check for DTCs in the PGM-FI system with the HDS.
Faulty ETCS
ACC activation indicator (on the MID) does not come on
Symptom troubleshooting.
  
ACC activation indicator (on the MID) does not go off
Symptom troubleshooting.
  
ACC indicator (on the MID) does not come on
Symptom troubleshooting.
  
ACC indicator (on the MID) does not go off
Symptom troubleshooting.
  
Senses a vehicle driving in another lane
Symptom troubleshooting.
Incorrect millimeter wave radar installation
Wheel alignment
Does not sense the vehicle driving ahead
Symptom troubleshooting.
Out of the performance limits
Wheel alignment
Undetectable environment
Intermittently senses the vehicle driving ahead
Symptom troubleshooting.
Incorrect millimeter wave radar installation
Wheel alignment
Undetectable environment