Both cam and crank sensors can be tested, but cleaning isn't going to restore life to either if they're bad.

The Camshaft Position Sensor (CMP) on the 6-cylinder engine is bolted to the top of the oil pump drive shaft assembly. The sensor and drive shaft assembly is located on the right side of the engine near the oil filter.

The CMP sensor contains a hall effect device called a sync signal generator to generate a fuel sync signal. This sync signal generator detects a rotating pulse ring (shutter) on the oil pump drive shaft. The pulse ring rotates 180 degrees through the sync signal generator. Its signal is used in conjunction with the crankshaft position sensor to differentiate between fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders.

When the leading edge of the pulse ring (shutter) enters the sync signal generator, the following occurs: The interruption of magnetic field causes the voltage to switch high resulting in a sync signal of approximately 5 volts .

When the trailing edge of the pulse ring (shutter) leaves the sync signal generator, the following occurs: The change of the magnetic field causes the sync signal voltage to switch low to 0 volts .


Found this on another forum, gunna see what happens tonight

I pulled and replaced the Crank Position Sensor in 15 minutes. That $75 sensor fixed everything.

Well I got 5 volts from the cam sensor..... Can a dealership test a PCM?

Yes. Or just google how. I'd tell you how but I've never had to do it.

They could not have put it in a better spot, I think it's to guard against theft.

I agree. Before i knew where it was i was looking all over the front of the motor near the crank pulley for a sensor. (you know, the usual location of such a sensor)

Who the hell decided to mount it to the bell housing?

And who the hell decided to use a bus system for the ECU to get data?

And who the hell.....forget it, this could go on forever...

All that tells you is you have input voltage. To accurately test a cam sensor you must follow the procedure you can find in a service manual.

The XJ computer cannot be tested unless you have specialized equipment. Very specialized equipment.