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Ron Z.
Ron Z., - Cadillac Tech -
Category: Cadillac
Satisfied Customers: 18966
Experience:  18+yrs experience. State Inspector and Cadillac Diagnostics
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How do I turn off the check engine light?

Resolved Question:

How do I turn off the check engine light?
Submitted: 6 years ago.
Category: Cadillac
Expert:  Ron Z. replied 6 years ago.

You can "reset" the Check Engine light by removing the "NEG" cable from the battery for 15min. Keep in mind: if the reason the engine light is on was not repaired properly, the light WILL return within 50-75 miles of normal driving, sooner if in a constantly mionitored system. If you did not make any repairs and would like to know why the engine light is on, AutoZone will read the "p-codes" for you for FREE.


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Customer: replied 6 years ago.
Is that the only way to remedy the check engine light. I thought there might be a switch button somewhere that you press. My STS also have adaptive cruise control I'm trying to get an answer for. I am for now, changing the brakes, oil and air filter, and bleeding the brake line, plus checking my transmission there a software to maybe check my car
Expert:  Ron Z. replied 6 years ago.

The only way to clear a check engine light is with the use of a scan-tool or to "reboot" the on-board computer by removing the "NEG" cable. No "reset switch".


When the Check Engine light comes on, it's the on-board computers way of telling you it sees a problem in one of the monitored systems. If you are not experiencing drivability issues (surging, stalling, rough idle, shifting issues, etc...), then more than likely it is a problem in the EVAP (emissions control) System. Unfortunately, there are litterally dozens of parts/sensors monitored by the PCM (on-board computer) in the EVAP System, and to take a "guess" would just be inefficient and a waste of time and money. A very common fail item is the Fuel Cap. Make sure it is tight and that the o-ring "gasket" on the underside is in good shape and free of visible defects (gaps, cracks, missing, etc). Fueling the vehicle while it is running can also set check engine light.. If the cap checks good, and you've done nothing out of the ordinary, then you need to start the disgnostic process. A good place to start is at your local parts store (ie. NAPA, AutoZone, Advanced). Most of these "big chain" stores will read the "p-codes" from the on-board computer for Free! Once you have these p-codes, it will tell you which system is faulting, and usually which sensor/part is the culprit (some testing is required), and then you can more accurately and efficiently make the repair.

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Customer: replied 6 years ago.
Thank you the check engine light is off. I have a feeling that the tire pressure sensor might be the problem. Anyway thanks again