If the Engine Control Module (ECM) has malfunctioned in your Nissan Quest, then you may want to replace it yourself. Professional repair estimates for the ECM can range from $2,000 to $3,000, depending on the repair shop. The Nissan Quest is notorious for having ECM problems because of the location of the ECM. The device is located under the windshield cowl, thus all water and rain drains directly onto this electronic device, causing it to rust and malfunction. Warranties usually do not cover rust problems, so many Quest owners have to foot the bill for an ECM repair.
Detach the negative cable on your battery and release the latch and wiring clips on the old ECM connectors. Use work gloves if you are concerned about protecting your hands from heat and dirt.
Remove the bolts that hold the ECM in place. The bolts are 10 mm, so use a small wrench for this task.
Pull out the ECM and set it aside. You should be able to see the rust and damage to your old ECM.
Protect your new ECM by painting the top cover with the water-resistant, ceramic paint. Be careful not to paint over the contact points for the ECM connectors. If you do, your new ECM won't work.
Secure your new ECM in place with new 10 mm bolts.
Connect the ECM connectors to the battery and latch the security clip underneath the ECM.
Reinstall the battery. Make sure the negative connection of the battery is securely fastened in place.
Crank your Nissan's engine, and reset your radio and clock settings. The new module will not have this saved information. Drive at a moderate pace to allow the module to acclimate itself to your driving environment.
