Fix It

Allow the vehicle to sit overnight without running to ensure the engine is cold. Hot oil can cause severe burns.

Remove the screws that attach the front cover of the oil pump to the front of the engine with a socket wrench. Disconnect the front cover from the engine.

Loosen the three bolts that connect the oil pump to the engine with a socket wrench. Remove the oil pump and its spacer from the engine.

Mount the oil pump spacer to the new oil pump. Fasten the new oil pump to the engine with the three mounting bolts. Tighten the mounting bolts with a socket wrench.

Connect the front cover for the oil pump to the engine with the retaining screws. Tighten the screws with a socket wrench. Start the engine and check for oil leaks.

Disconnect the cable on the negative terminal for the battery with a socket wrench to prevent the unintentional discharge of electricity. Open the door to the fuel tank filler, and disconnect the electrical connector for the fuel sending unit.

Remove the protective cap for the pressure fitting on the fuel line, and connect G.M. tool no. J-5420 to the pressure fitting. Wrap a shop rag around the pressure fitting, and slowly open the valve on the tool to relieve the pressure in the fuel system. Disconnect the tool from the pressure fitting, and replace the protective cap.

Siphon the fuel from the fuel tank into a gasoline container. Raise and support the rear of the vehicle with jack stands, and disconnect the ground wire for the fuel sending unit with a screwdriver. Detach the fuel lines from the fuel tank, and support the fuel tank with a wooden block on top of a jack. Remove the screws for the support straps of the fuel tank. Lower the fuel tank slightly, so you can disconnect the electrical connector for the fuel pump. Lower the fuel tank completely, and remove it from the vehicle.

Remove the nuts that fasten the fuel gauge unit to the fuel tank with a socket wrench. Turn the locking ring for the fuel pump counterclockwise with a brass punch and hammer. Remove the locking ring, and lift the fuel pump from the fuel tank.

Install the new fuel pump by performing steps 1 through 4 in reverse order. Tighten the screws for the fuel tank retaining strap to 25 ft. lbs. with a torque wrench. Start the engine, and check for fuel leaks.

Start the engine and let the 1993 DeVille warm up. On some GM cars, including the Cadillac line, once the engine has warmed up, the gearshift may be operable. Also, check to ensure the brake pedal is working by pressing down on it. If warming up the car doesnt resolve the problem, go on to the next step.

Manually trip the brake shift interlock solenoid. Start the car. Lift the rubber panel cover under the ashtray and open the under-dash compartment door.

Shine a flashlight into the under-dash compartment and look for an orange lever tab. Push orange lever tab toward the hood of the DeVille to override the automatic lock manually. Listen for a click that indicates the solenoid has been released.

Depress the brake pedal again and attempt to shift the Cadillac into gear.

Remove the cover that surrounds the license plate area and runs along the bottom of the light assembly. Use a small flat head screwdriver to start the removal, taking care to not scratch the paint on the cover.

Use the screwdriver to pop the light assembly out of its retaining clips. Be especially caul when loosening the light assembly, since it can crack if you apply too much force.

Press on the clip on the light assemblys plug that is joined with the wiring harness inside the trunk. Place the old light assembly to the side on a soft cloth.

Insert the plug on the new light assembly into the socket in the wiring harness. Line the tabs on the back of the light assembly with the retaining clips on the trunk lid.

Press the light assembly into place gently, listening for the retaining clips to snap. Make sure the light assembly does not jiggle at all; otherwise, remove it and install it again.

Press the cover that goes around the license plate area and underneath the light assembly back into place so its retaining clips snap into place. Make sure the cover does not jiggle when you press on it.

Pull down on the fuse panel cover from the top with your fingers. You can find it on the lower part of the drivers side dashboard. Plug the OBD scanner into the port.

Put the key into the ignition and turn it to the "On" position, but dont crank the engine.

Select the "Delete Codes" command on the scanner. Wait for the menu to indicate the task has been accomplished. Unplug the OBD scanner.

Turn on the engine and verify all service and warning lights have been turned off on the instrument panel.