How do you reset the check engine light on a Chevy Cavalier?
The check engine light on a Chevy Cavalier can be reset by clearing the stored fault codes with an OBD-II scanner, or, if you don't have a scanner, by safely disconnecting the battery to reset the powertrain control module. This guide covers both methods, what to expect after resetting, and cautions about reoccurring issues.
Resetting with an OBD-II scanner
If you have access to a consumer OBD-II scanner, use it to read and clear fault codes stored in the engine control module (ECM). Clearing codes does not fix the underlying problems; you must address any faults that triggered the light.
What the tool does and what to know
An OBD-II scan tool reads diagnostic trouble codes (DTCs) stored in the ECM and can clear them once the underlying issue is addressed or when you simply want to turn the light off after repair. After clearing, the vehicle's readiness monitors will run during a drive cycle, and the light may come back if a fault is present.
- Locate the OBD-II port under the dash on the driver's side (usually near the knee area).
- Turn the ignition to ON with the engine off and connect the scanner to the port.
- Use the scanner to read the stored codes and note any faults.
- Choose the option to Clear Codes or Erase Codes, then confirm if prompted.
- Turn the ignition off, disconnect the scanner, then start the engine and drive normally for a few miles to re-check for codes.
Clearing codes should turn off the CEL only if there are no active faults; if a fault persists, the light will return and you should repair the issue before rechecking.
Resetting without a scan tool
If you don’t have an OBD-II scanner, you can attempt a reset by power-cycling the ECM. This method clears memory but does not diagnose or fix any fault; you may need to address the underlying issue if codes return.
- Ensure the car is in Park, the parking brake is set, and the ignition is off.
- Disconnect the negative battery cable (the black cable) using a wrench; leave it disconnected for 10–15 minutes to drain the ECM’s power.
- Reconnect the negative battery cable and tighten the connection securely.
- Turn the ignition to ON, start the engine, and take the car for a short drive to allow the ECM to relearn and to run its readiness monitors.
Note: This method will also reset other systems such as the radio, clock, and some memory settings. If your Cavalier has an anti-theft radio or requires a security code, have those codes handy.
Important notes for older Cavaliers
Most Cavaliers built after 1996 use OBD-II. Early models (roughly 1994–1995 in some markets) used OBD-I, which doesn’t always support consumer-friendly code clearing. In those cases, a dealer or professional shop with the correct tools may be needed to read and reset codes. Regardless of method, clearing the light does not fix the root cause; only addressing the fault will prevent the light from returning.
Summary
To reset the check engine light on a Chevy Cavalier, use an OBD-II scanner to read and clear codes, or power-cycle the ECM by disconnecting the battery if you lack a scanner. Always remember that the light will reappear if a fault remains, and some issues require professional diagnosis. After resetting, drive the vehicle to allow readiness monitors to complete and confirm the light is truly off.
