Check Engine Light Went Off After a Week

A car’s check engine light illuminates whenever the computer detects any error codes or malfunction in the system.

In minor cases, the computer resets the codes and deactivates the CEL, while the major issue takes time and physical inspection.

If your car’s check engine light went off after a week, solving the temporary fault code or intermittent problem may have taken time.

Tightening the loose gas cap or restoring the faulty sensor can deactivate the CEL after a week. However, it’s better to diagnose the car by an expert mechanic with an OBD-II scanner to prevent the CEL from triggering once again after weeks or months.

Why Does My Car’s Check Engine Light Went off After a Week?

Check engine light may turn on due to minor problems like emissions-related issues that may clear themselves. So, it isn’t uncommon to see a car’s CEL turn off after a week.

However, some serious problems like faulty sensors, damaged bumps, or other components can also trigger this issue. So if your car’s CEL keeps coming on and off, troubleshoot the vehicle keeping these reasons in mind:

1. Temporary Fault Code

The check engine light works because when you use the car, its computer checks for faults through the sensors. The ECU records a temporary fault code each time the sensor finds a fault.

If the ECU records the same fault over time or during using the vehicle for five consecutive times, the computer makes the error code permanent and triggers the check engine light.

So the check engine light can go off itself if the fault code recorded isn’t permanent and not present the next time you use the vehicle. It can even come back after a week unless you fix the fault.

2. Miss Detected

According to the owner’s manual for the 1996 Chevy Cruz, the check engine light may come on due to causing misdetection.

If you can start the vehicle three times without miss detection, the CEL should turn off automatically. Turning off the CEL can take a week, mainly if you don’t use the car regularly.

Miss detection occurs when the gas gauge needle touches the high side of the 5/8 tank mark during driving. To avoid this problem, refill the gas tank and drive the car normally or re-start the engine three times and wait a minute between cycles.

3. Intermittent Problem

Your car’s check engine light may stay on for days and turn off after a week due to intermittent problems.

If the car ECM senses problems like a faulty variable valve control system, a misfire from the coil, or a leak in the gas cap, it can trigger such an issue. The CEL may keep coming on and staying solid until you solve the issue.

4. Loose Gas Cap

A loose gas cap may also turn on the check engine light, which may deactivate if the cap tightens automatically. Attaching a new gas gap may also turn off the check engine light if activated due to a missing cap.

5. Faulty Sensor

A damaged sensor is also a potential source that can trigger a check engine light. If so, the CEL may turn off automatically after a week, and the computer will reset it.

If the problem is significant, you may need to replace the sensor to turn off the light. The electrical glitch can also cause CEL, which may be fixed automatically after resolving the glitch.

6. Burn Out Bulb

After starting a car, it checks the dash light and briefly illuminates the check engine light. The bulb may burn out if you don’t see this while starting the engine. The check engine light may turn on and off until it is completely damaged.

7. Drive Cycles Completed

The OBD system usually waits for a few cycles of driving (engine turns on and off) before finding the same problem and repairing a small malfunction. That is why the light can come on after driving for several days or a week.

8. Battery Voltage Fluctuations

Check engine light caused by a low or high battery voltage. The light might go out when the battery charges or settles.

9. Drive Cycles Completed

The OBD may delay for a few drives (so that the engine does not start and then restart) without picking up the same problem before it registers a small fault. That’s why the light can stop after a few days or weeks of driving.

Is It Normal If Check Engine Lights Went Off After a Week?

Turning off the check engine light after a week isn’t normal for a car. If the light illuminates for a few days and turns off, bring the car to a service centre for free code reading. CEL automatically turning off doesn’t mean that the problem triggered by this light is fixed.

Some codes activate the check engine light until it clears, regardless of whether it is a history or current code.

Some logic codes deactivate the CEL after three trips without any fault occurring. So if your car’s CEL deactivates itself after a week, the problem is most possibly intermittent and requires deep diagnosis by an expert technician.

If you keep driving the vehicle in this condition, it can trigger limp mode. So you’ll have limited access to your car and won’t be able to drive faster or more efficiently.

What To Do If Check Engine Lights Went Off After a Week?

If your car’s check engine light goes off after a week, the minor issue that triggers the light is most likely resolved.

It also saves you money that the mechanic may charge. But most of the time, bad sensors trigger the CEL. So, it can once again trip the CEL in a few weeks to a month. Burnout light may also cause the same issue.

To fix the issue, take the vehicle to an auto repair shop to look for hidden codes that may activate the check engine light.

Hidden codes are usually issued for the vehicle’s engine, which ECU can determine. These don’t turn on the check engine light unless certain criteria are met.

Depending on the underlying source of the problem, the mechanic will use an OBD-II scanner to get codes like P0171-P0175 or P0420 and P0430 to act accordingly.

Also Read: Check Engine Light Flashing When Accelerating

FAQs on Check Engine Lights Went Off After a Week

Final Words

If your car’s check engine light goes off after a week, don’t panic. Your car’s computer may reset the temporary faults code stored on the computer and deactivate the light. But if the light illuminates again, bring the car to an auto repair shop to diagnose the vehicle.

Whether it is an intermitted issue or hidden codes, the problem should be solved successfully. Leaving the problem untreated can cause safety hazards.