Why is my Cadillac Check Engine Light ON?
Updated 2 weeks ago
Does your Cadillac Check Engine Light (CEL) stay on or is flashing? In this guide, you will find instructions on how to diagnose Cadillac check engine light yourself. Cadillac check engine light can turn on for various reasons including something as simple as a loose gas cap.
Reading fault codes to find out why your Cadillac check engine light is ON should be the first troubleshooting step. Do not ignore CEL and always pull the fault codes even if your Cadillac runs and drives fine.
If you are subscribed to OnStar, press the button to connect to an Advisor. They can run a diagnostic check and retrieve the trouble code(s) from the Engine Control Unit (ECU).
If you are not subscribed to OnStar you can find a repair shop or auto parts stores that can read the codes for free. Or if you are a DIYer follow the instructions below to read the fault codes yourself. This procedure is very easy and takes less than five minutes.
Symptoms of a check engine light can vary depending on the fault code that triggered the light. Possible symptoms include:
- Poor throttle response
- A decrease in fuel economy
- Engine misfire
- Difficult to accelerate or going uphill
- Engine shakes or excessive vibrations
- Car won't stay running
The check engine light may be on, with no symptoms. Even if there are no symptoms it is important to read the fault codes to find out why CEL is on.Back to top
What you will needBack to top
Reading Cadillac check engine light codes and resetting it once you fix the problem is very easy. Any Cadillac owner can read and clear Cadillac check engine light at home. This procedure works on Cadillac ATS, CTS, XTS, CT6, XT5, Escalade, SRX, DTS, STS, BLS, XLR and other models.
Locate OBD-II Port
Locate OBD-2 port under the dashboard of your Cadillac on the driver's side. This is a 16-pin port and all 1996 and newer Cadillac vehicles have this port.
Plug in your scanner or Bluetooth adapter into the OBD2 port.
Turn On Ignition
Turn ignition ON, key in position II. All Cadillac dashboard lights will turn on but do not start the engine. If your Cadillac has Start/Stop button you will need to press the START button without pressing the brakes.
Turn on scanner
Allow your OBD2 scanner to turn on and connect to your Cadillac Engine Control Unit (ECU). This step can take up to one minute.
Read Cadillac check engine light codes from the Engine Control Unit (ECU)
Once you have read the codes and fixed the underlying problem, you can come back to clear Cadillac CEL codes. Go to Erase Codes menu. Select YES to clear Cadillac check engine light.