On the 2003 Mazda Protégé, the crankshaft position sensor detects crankshaft angle every 10 degrees of rotation. It then relays this information back to the power train control module so it knows when to fire each spark plug. Failure of the sensor may result in several symptoms; the most severe of these is a complete cutting of the fuel and spark, which keeps your Protégé from starting. Replacing the crankshaft position sensor on the 2003 Protégé is a straightforward task, whether you have the economical DX model or the turbo-charged Mazdaspeed model.
Loosen the right-front lug nuts with a ratchet and socket. Raise the front of the Protégé with a floor jack, and slide jack stands under its subframe. Lower the vehicle onto the floor jacks. Remove the lug nuts and pull the wheel from the front hub.
Remove the bolts securing the passenger-side wheel well liner, using a ratchet and socket, and pull the wheel well liner from the vehicle, exposing the crankshaft pulley behind it.
Find the crankshaft sensor next to the crankshaft pulley, toward the front of the vehicle. Press and hold the unlocking button on the crankshaft sensor’s wiring harness, and pull the Protégé’s wiring harness from the sensor’s harness.
Grab the crankshaft position sensor’s wiring harness and pull it away from the engine block firmly to disengage its retaining clip.
Remove the two bolts securing the crankshaft position sensor, using a ratchet and socket, and remove the crankshaft position sensor from the engine.
Position a new crankshaft on the engine, aligning the bolt holes on the sensor with those on the sensor. Hand-thread the two crankshaft position sensor bolts, then tighten them to 7 foot-pounds with a torque wrench and socket.
Route the crankshaft position sensor’s wiring so it is out of the way of all of the belts, then line up the clip on the wiring harness with its hole in the engine. Press the harness toward the engine to engage the retaining clip, securing the harness in place. Plug the Protégé’s wiring harness into the sensor’s harness.
Reposition the wheel well liner into the right-front wheel well, and hand thread its bolts. Tighten the wheel well bolts with a ratchet and socket.
Set the wheel back on the Protégé’s hub and hand thread the lug nuts. Raise the vehicle off the jack stands with a floor jack, and remove the jack stands. Lower the Protégé to the ground. Tighten the lug nuts, in a crisscross pattern, to between 65 and 87 foot-pounds with a torque wrench and socket.
