Changing a Camshaft Position Sensor

The purpose of the camshaft position sensor is to sense the position of the camshaft relative to the opening of the intake on the number 1 cylinder prior to compression stroke. It sends this signal to the computer, which uses this information to adjust the on time for the fuel injectors. It is a hall effect sensor--a magnet in a fixed position very close to the camshaft, which has a reluctor (a round metal cup with graduations or cuts on the vertical sides evenly spaced) that passes in front of the sensor. A 5-volt electrical current runs through the sensor to ground. When the reluctor open-section passes in front of the sensor, there is voltage to ground. As the metal section passes in front, the ground is collapsed causing an on and off power pulse recognized by the computer.

You will need some basic tools:

Common screwdriver
Set of wrenches
¼-inch drive ratchet
Set of ¼-inch drive sockets

Locate the camshaft sensor. Location depends on the make, model and engine size. This being the case, let's talk about the common factors and it will be easier to find. First, of course it must be extremely close to the camshaft. In a V8 engine with a conventional camshaft, the sensor would need to be either directly above the water pump or in the top rear of the intake manifold. If the engine has overhead camshafts, the sensor will be located in the valve cover.

Foreign vehicles with a distributor have the camshaft sensor inside the distributor, and it is not serviceable. Some conventional V6 engines have the camshaft sensor in the side of the block, close to the firewall. It generally has three wires and is round. On Fords, for instance, the camshaft sensor is in the rear of the engine under the intake manifold and has a round cup-looking cover to protect it.

Pull the electrical connector off the sensor. Remove the 10 mm bolt in the bracket, holding the sensor to the block, using a socket. Twist the camshaft sensor in both directions as it is pulled out of the block.

Install a new O-ring on the new camshaft sensor and wipe a small amount of oil on the O-ring to help it seat in the block. Install the new cam sensor into the block and press it down until the O-ring pops into its cavity.

Install the hold down bracket and bolt and tighten. Plug in the electrical connector on the sensor.