1. Gather your tools. You will need a 10mm wrench and a jumper wire or safety pin.
2. Locate the diagnostic port. The diagnostic port on the 1998 Land Rover Discovery Series 1 is located under the hood, near the battery.
3. Locate the pins A and B. The diagnostic port has 16 pins, labeled A through P. Pins A and B are located in the second row from the bottom, on the left side of the port.
4. Insert the jumper wire. Insert one end of the jumper wire into pin A and the other end into pin B.
5. Turn on the ignition. Turn the ignition key to the "II" position, but do not start the engine.
6. Wait for the check engine light to turn off. The check engine light will remain on for a few seconds, then it will turn off.
7. Disconnect the jumper wire. Once the check engine light has turned off, disconnect the jumper wire from the diagnostic port.
8. Start the engine. Start the engine and let it run for a few minutes. The check engine light should remain off.
If the check engine light returns after following these steps, it means that there is still a problem with your car that needs to be addressed. You should take your car to a qualified mechanic to have it diagnosed and repaired.
