How to Change a Crankshaft Position Sensor

A crankshaft position sensor is a common feature of the modern engine. It is a small instrument that measures and tracks the crankshaft position and speed. The information it gathers is utilized by the car’s computer control system to maintain ignition times and engine function. When the crankshaft position sensor begins to weaken, it results in engine stalling and backfiring of the ignition. In such a case, you will need to change the crankshaft position sensor.

Step 1 – Prevent Shocks and Other Accidents

The first step is to take care of the car battery. Disconnect the negative battery ground cable before you begin the install process. This is an important safety measure that ensures there will be no accidental shocks that could injure you and damage the car’s electronic panel.

Step 2 – Locate the Crankshaft Position Sensor

The second step is to find the crankshaft position sensor itself. The location of the sensor varies according to the make of the car, so it is best to refer to the vehicle’s manual to save time and to determine the exact location. Usually it is placed in front of the engine, by the main pulley. In some cars, the sensor may be placed at the side of the engine or at the rear instead.

Step 3 – Remove the Crankshaft Sensor

Once you’ve found the sensor, it’s time to remove and replace it. You’ll notice that the crankshaft position sensor is bound in place by a bolt and wires. First, remove the wire harness (it is generally comprised of three wires) from the sensor. Pay attention to the wire connections as you will have to reattach them in the same order once you install the new one. Take a picture with your cell phone if needed.

When the wires have been disconnected, pry out the bolt with a socket wrench. You can remove then the failing sensor and replace it with the new piece.

Step 4 – Install the New Crankshaft Sensor

Once you remove the old sensor, place the new one in exactly the same slot. This part is a little tricky. The sensor is sealed to the interface with a mechanical gasket better known as an O-ring. When you change the crankshaft position sensor, you also need to reinstall a fresh O-ring, as the old one can’t be reused. Place the O-ring around the sensor as you put in into place. When you are done, reconnect the wire harness in the same order as they were prior to the install. Usually, the unit will lock into place and you won’t have to put in any additional work beyond this stage, but if the sensor does not lock into place and requires manual adjustment, use a paper spacer to achieve the proper result.

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