How do I reset the check engine light on a 1999 Honda Accord?

The check engine light can be reset by clearing the stored diagnostic trouble codes with an OBD-II scanner, or by temporarily disconnecting the battery for about 10 minutes. After clearing, drive the car to allow the onboard monitors to re-run. If the light returns, there is still an unresolved fault that needs repair.

What the check engine light means in a 1999 Honda Accord

On a 1999 Honda Accord, the check engine light (CEL) indicates a fault detected by the engine or emissions control system. The car’s computer stores diagnostic trouble codes (DTCs) that point to the area needing attention—ranging from a loose gas cap to faulty sensors or more serious drivetrain issues. Clearing the light without fixing the underlying problem can cause the vehicle to run poorly or fail an emissions test, and the codes may return once the monitors run again.

Two practical methods to reset the light

Using an OBD-II scanner to clear codes

Using a scan tool is the most reliable way to reset the CEL because it lets you read and then erase the exact stored fault codes, helping you verify whether the problem reappears after the reset.

1. Turn the ignition to the ON position with the engine off.


2. Connect the OBD-II scanner to the vehicle’s data link connector (DLC) located under the dash, usually near the steering column.


3. Follow the scanner prompts to read the stored DTCs and note any codes for reference.


4. Use the scanner’s option to clear or erase the codes from the memory.


5. Turn the ignition off, wait a moment, then start the engine to see if the CEL remains illuminated.


6. Drive the car for a short distance to allow the readiness monitors to run and complete.

Clearing with a scanner removes the stored codes; if a fault is present, the light may come back once the monitors complete their checks.

Resetting by disconnecting the battery

As a fallback or when a scanner isn’t available, you can reset the codes by briefly disconnecting the battery. Keep in mind this can reset other systems and may require re-entering a radio code on some vehicles.

1. Ensure the ignition is off and the keys are removed.


2. Use a wrench to disconnect the negative battery cable from the terminal, then wait 10 to 15 minutes.


3. Reconnect the negative battery terminal and snug things up securely.


4. Turn the ignition to ON (engine off), then start the engine to check if the CEL goes out.


5. Drive normally for a short drive to allow the onboard monitors to run and re-learn sensor data.

Note: On some Hondas, disconnecting the battery may prompt the radio to request a code; have the code handy if needed. If the light returns after a drive cycle, the underlying issue still needs repair.

What to do if the light stays on or returns

If the CEL remains illuminated after attempts to reset, you should diagnose with a scan tool to retrieve the DTCs and address the underlying problem. Common causes on a 1999 Accord include a loose or missing gas cap, faulty oxygen sensors, a failing mass airflow sensor, vacuum leaks, ignition faults, or issues in the catalytic converter. A professional inspection can help identify and fix the specific fault.

Additional considerations and best practices

Before attempting a reset, it’s wise to address the underlying fault indicated by the codes. Clearing codes without repair can mask continuing problems and may lead to failed emissions testing. After any repair, check that all monitors run to completion by driving the vehicle for a proper drive cycle and re-scanning to confirm the light stays off.

Summary

Resetting the check engine light on a 1999 Honda Accord can be done with an OBD-II scanner or by briefly disconnecting the battery. The scanner method is preferable because it allows you to read and verify codes before clearing them. If the light returns, or if you can’t determine the fault, consult a mechanic to diagnose and repair the root cause. Always drive the vehicle after a reset to ensure the onboard monitors complete their checks and to confirm the light does not reappear.

How do you manually clear the check engine light?

Turn off the ignition and open the hood, then use a wrench to disconnect the negative battery cable. Wait about 15 minutes, then reconnect the battery cable and tighten it securely. Start the car to see if the CEL has reset. The downside is this may erase radio presets, clock settings, and ECU memory.

Can I clear my check engine light myself?

Turn it to the on position. But don't start the engine. Then turn it off do this three times in a row on the fourth. Try turn the key and start the car.

How do I reset the check engine light on a Honda Accord?

Reset Your Check Engine Light Manually

1. Turn off the engine and pop the hood.
2. Take off any jewelry and put on safety gear, including gloves and glasses.
3. Look for the negative terminal on your car battery.
4. Loosen the terminal and disconnect the negative cable for 30 to 60 seconds.

How to reset check engine light on a 1999 Honda Accord?

How to Reset Honda Check Engine Light

1. Turn off the ignition.
2. Locate the negative terminal.
3. Loosen the nut on the negative terminal with a wrench.
4. Reconnect the negative cable and tighten it back up with your wrench.
5. This should reset the check engine light for your Honda car.