Here's why and what you should do:
* The Problem Still Exists: Disconnecting the battery might temporarily clear the light, but the underlying issue causing the CEL remains. Driving with a malfunctioning system can lead to further damage, reduced fuel economy, and even safety hazards.
* Diagnostic Trouble Codes (DTCs): The CEL is triggered by one or more DTCs stored in the PCM's memory. These codes identify the specific problem. You need to know the codes to fix the problem.
To properly address the Check Engine Light:
1. Obtain Diagnostic Trouble Codes (DTCs): You have several options:
* OBD-II Scanner: The most reliable method. Buy a relatively inexpensive OBD-II code reader from an auto parts store. Plug it into the OBD-II port (usually under the dashboard) and it will read the codes. Many scanners also allow you to clear the codes *after* the problem is fixed.
* Auto Parts Store: Most auto parts stores will scan your car's codes for free. They can often give you a preliminary diagnosis based on the codes.
* Mechanic: A mechanic can diagnose the problem accurately and provide a repair quote. This is the best option if you're not comfortable doing repairs yourself.
2. Repair the Problem: Once you know the DTCs, research the likely cause (plenty of online resources exist). If you're mechanically inclined, you might attempt the repair yourself. Otherwise, take it to a mechanic.
3. Clear the Codes (After Repair): *Only after you've addressed the underlying problem* should you clear the codes. Most OBD-II scanners have a "clear codes" function. After clearing the codes, drive the vehicle for a while; if the problem is truly fixed, the CEL won't return. If it does come back, you'll need to re-diagnose the issue.
In short: Don't just try to reset the light. Find out *why* the light is on and fix the problem. This is crucial for maintaining your vehicle's performance and safety.
