Diagnostic Test

WARNING: This page is about a different car, the 2010 Dodge Charger and 2010 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.

VERIFY DTC IS ACTIVE
NOTE: To help in the service of the ACC System, it is recommended speaking to the customer to find out what type of environment they were driving in when the cruise concern took place. Heavy rain, snow, ice, and fog can cause the ACC system to become unavailable. This should be considered normal operation and no repair is necessary.
1. Using a scan tool, read ACC DTCs.
  Is the DTC active at this time?
  
  Yes
  - Go to step 2
  No
  - No repair is necessary. Make sure the lens is free of dirt, damage, and other obstructions.
  - Perform ADAPTIVE CRUISE CONTROL VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Adaptive Cruise Control (ACC) - Standard Procedure .
CHECK FOR DTCs IN THE ECM/PCM
1. Using a scan tool, read ECM/PCM DTCs.
  Are there ECM/PCM DTCs present?
  
  Yes
  - Perform the appropriate diagnostic procedure. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Diagnosis and Testing for gasoline engine .
  No
  - The ACC Module has detected the ambient temperature above operating range. Once the temperature has decreased below 85°C (185°F), ACC operation will be restored.
  - Perform ADAPTIVE CRUISE CONTROL VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Adaptive Cruise Control (ACC) - Standard Procedure .