1. Turn the key to the "On" position, but do not start the engine.
2. Press and hold the "Off" button on the climate control panel for 5 seconds.
3. The display will show "Diagnostics".
4. Press the "Up" or "Down" buttons to scroll through the diagnostic codes.
5. The codes will be displayed in two-digit format. The first digit is the main category, and the second digit is the specific code.
6. Refer to the Cadillac Deville owner's manual for a description of the diagnostic codes.
Main Categories
* 10 - Body Control Module (BCM)
* 20 - Engine Control Module (ECM)
* 30 - Transmission Control Module (TCM)
* 40 - Anti-lock Braking System (ABS) Module
* 50 - Air Bag Control Module (ABCM)
* 60 - Climate Control Module (CCM)
* 70 - Radio Control Module (RCM)
* 80 - Security Control Module (SCM)
Specific Codes
* 51 - Low coolant level
* 52 - Engine overheating
* 61 - Transmission slippage
* 71 - ABS malfunction
* 81 - Air bag deployment failure
Clearing Diagnostic Codes
Diagnostic codes can be cleared by disconnecting the battery for at least 10 minutes.
