How to Reset the Computer on a 2001 Ford Expedition After a Tune Up

Change your Expedition's spark plugs every 100,000 miles

Under normal circumstances, there is no need to reset the computer on a Ford Expedition after performing a routine tune up. However, if other related repairs were performed in conjunction with the tune up, due to codes stored in the power train control module, then those codes will need to be cleared, which is essentially all that is involved with resetting a computer. If the check engine light comes on after a tune up is performed, and it wasn't on prior to the tune up, recheck your work to make sure everything was done properly and nothing else was undone during the procedure.

Things You'll Need

• Scan tool
• Ignition key
• Paper and pen

Instructions

1. Get into the Expedition's driver's seat with the scan tool and find the diagnostic port, located under the driver side dash board. The port has a protective cap on it with the letters "DTC" on the cap.

2. Pull the protective cap off the port and plug datalink cable from your scan tool into the port. You can purchase a usable scan tool for around $100 at most auto parts stores. Better quality scan tools, with better features and abilities can be had for considerably more. Make sure the scan tool works with Ford vehicles before you purchase it.

3. Follow your scan tool's specific operating instructions for running a self test on the Expedition. You may need to insert the ignition key prior to the scan tool powering up and may be prompted to turn the key on or off during the test.

4. Run the self test in accordance with the instructions in Step 3. When prompted to do so, clear any codes that might exist. You might want to write down the codes on a piece of paper for future reference before you clear them out.

5. Finish the self test and disconnect the datalink cable after the test is complete. Don't forget to put the protective cap back in place over the diagnostic port to prevent damage to the pins and to keep dirt and dust out of the port.

Tips & Warnings

• Misfire codes are commonly stored in the computer when your Expedition needs a tune up. When the engine is misfiring, the check engine light may blink on and off to alert you to the misfire. Once the misfire has been corrected by installing new spark plugs and wires, the computer will turn the light off itself, if it detects no misfires during the next test. However, this may take several miles of driving before the test is run again.

• Oddly enough, platinum spark plugs can often run well long past their life expectancy before they begin to cause misfires. However, a plug worn beyond its limits will cost you fuel economy and engine performance. Ford Motor Company recommends you replace the plugs every 100,000 miles.

References

• Ford Service: scheduled maintenance guides