How to Repair a Wiring Harness & Throttle Position Sensorby Cayden Conor
The wiring harness on a vehicle seldom malfunctions unless the wires rub against something or an animal chews through the wires. The wiring harness for the throttle position sensor is contained in the main wiring harness and is well protected, except for the short part of the harness that leads from the main harness to the throttle position sensor --- its pigtail. The throttle position sensor and its pigtail are easy to reach on most vehicles, and is usually on the top of the intake manifold or on the throttle body, depending on the type of fuel injection on your vehicle.
Unplug the wiring harness connector on the throttle position sensor. Unbolt the sensor from the intake or throttle body, using the appropriate socket. Install the new throttle position sensor and tighten the bolts firmly. Plug in the wiring harness connector if you are not going to change it.
Cut the wires on the pigtail about 1 inch away from where they enter the main wiring harness. Strip about 1/2 inch of the insulation off the wires at the main wiring harness connector.
Insert each one of the bare wires into a separate butt connector. Crimp the butt connectors onto the wires, using the crimping tool or pliers.
Strip about 1/2 inch of the insulation off the new pigtail. Matching the wire colors, insert the wires into the ends of the proper butt connectors on the main wiring harness. If you do not match the wiring harness colors, the throttle position sensor is not going to work, and depending on the vehicle, you could cause more damage to the wiring harness.
Crimp the butt connectors onto the pigtail with the crimping tool or pliers. Gently tug the wires to ensure they are crimped into the butt connectors. Wrap the butt connectors, including 1 inch of wire on each side of the butt connectors, with electrical tape.
Plug the code scanner into the data link port on your vehicle. Turn the key to the "On" position, then press "Erase" on the code scanner. Test drive the vehicle to ensure it drives correctly and that the engine light does not come on again.