The 2005 Toyota Corolla was offered with the 1.8-liter four-cylinder engine with an automatic transmission or a five-speed manual transmission for the XRS trim level. The electronic control module or ECM is located under the dashboard and behind the glove compartment drawer. To access the ECM, the glove compartment drawer will have to be removed. When replacing the ECM, the replacement unit must be flashed by a Toyota dealership or a parts store that has ECM flashing equipment.
Document the VIN number that is viewable at the bottom of the windshield on the driver side of the vehicle. Turn the ignition key to the On position and document the mileage on the odometer. Turn the ignition key off.2
Lift the vehicle hood and support it with the hood prop rod. Loosen the negative battery terminal with the socket and ratchet. Disconnect the negative battery cable from the negative battery terminal.3
Enter the passenger side of the vehicle and open the glove compartment drawer. Locate the drawer stoppers -- there is one on each side of the drawer. Remove the screw for each door stopper. Carefully squeeze on the sides of the drawer at the very back while pulling out on the drawer to release the upper drawer stoppers. Lift the drawer up to remove it from the dashboard.4
Remove the two clips for the ECM cover with the flat-head screwdriver. Remove the cover from under the dashboard. Pop open the ECM wiring harness clamp with the flat-head screwdriver and disconnect all four ECM wiring harness connectors from the ECM.5
Remove both bolts that secure the ECM brackets to the underside of the dashboard with the socket and ratchet. Locate the rear mounting clip. Squeeze the tongs on the back of the clip and push the clip through the mounting hole. Unfasten the mounting claw at the front of the ECM and lower the ECM and bracket assembly from under the dashboard.6
Remove the screws for the ECM brackets with the socket and ratchet. Remove the brackets from the ECM. Compare the ECM that has been removed from the vehicle with the replacement. If the original ECM was manufactured by DENSO it must be replaced with a DENSO unit. If the original unit was manufactured by DELCO, it must be replaced with DELCO.7
Take the replacement ECM to a Toyota dealership or local parts store along with the VIN number and mileage for flashing.
Install the ECM brackets onto the replacement ECM and tighten the mounting screws to 28 inch-pounds with the inch-pounds torque wrench.9
Lift the ECM into position under the dashboard and push the rear mounting clip through the mounting hole. Fasten the front mounting claw connector. Install the ECM bracket to dash mounting bolts and tighten to 27 inch-pounds with the inch-pounds torque wrench.10
Plug each plug into its terminal on the ECM; they will click when properly installed. Set the wiring harness into the harness clamp and lock the clamp closed to secure the harness.11
Lift the ECM protective cover into position and install the retaining clips. Set the glove box drawer into position. Squeeze the upper sides of the drawer so that the upper stops will clear the opening in the dashboard and push the drawer back into the hole. Line up the lower stops to the mounting holes on each side of the drawer and install the lower stop mounting screws. Close the glove box drawer.12
Install the negative battery cable to the negative post on the battery. Tighten the negative battery terminal with the socket and ratchet. Shut the hood.