How to test a GM 3-wire crank sensor?

The tests shown in this video can be used for any 3-wire cam or crank sensor. The P0336 code was caused by the crank sensor connector being left unplugged. So rather than just plug the sensor back in and clear the codes, I decided to take this opportunity to show you how to test the crank sensor circuit on this car. (1996 GM 3100)

How do you test a two wire sensor?

Testing A Two-Wire Sensor In the two wire system – the magnetic type, you need to do the resistance test first. Take the multi meter and set it to AC volts. Check for the connector as well and make sure no dirt or mud is in there. Continuing to the crank position sensor test, ask someone to turn the ignition key on; do not start the engine.

How to test the cam sensor diagnostic trouble?

No scan tool required for the cam sensor test since a scan tool is not gonna’ be much help. Aslo a resistance test of the cam sensor will get you no-where since the camshaft position sensor is a Hall Effect type sensor that can not be Ohm-ed (resistance tested) with a multimeter.

How to test crankshaft and camshaft position sensors?

Here is how you can easily test both your crankshaft position sensor and camshaft position sensor. It’s very important to be able to test these sensor since because they control your ignition and fuel injector pulse and if they fail they could cause a Crank No start condition.

What should the voltage be on a crankshaft sensor?

Touch the DMM red lead to each of the sensor wires on the harness connector you just unplugged. One of the wires should produce around 1.5 volts; otherwise, the sensor is not receiving a reference voltage, and needs to be fixed. Disable the fuel system by removing the fuel pump fuse or relay.

What should the CKP sensor read on a crankshaft?

Touch the DMM red lead to the red (power) wire on the harness connector. You may need to check the wiring diagram for your particular model, if the CKP sensor uses wires of different color to identify the ground, power and signal wires. Turn the ignition key to the On position. Your meter should read between 5 and 13 volts.

What are the codes for the crankshaft position sensor?

A diagnostic scan tool could show any of the following codes: 1 P0335 Crankshaft Position Sensor A Circuit Malfunction 2 P0336 Crankshaft Position Sensor A Circuit Range/Performance 3 P0337 Crankshaft Position Sensor A Circuit Low Input 4 P0338 Crankshaft Position Sensor A Circuit High Input 5 P0339 Crankshaft Position Sensor A Circuit Intermittent

How to test the position of the camshaft?

Touch the black probe on your meter to ground and the other probe to the power wire. Compare your reading to the specification in your manual. Have your helper crank or start the engine. Touch the signal wire with the red probe from your meter and the ground wire with the black probe.

What to do if your camshaft has trouble code p0340?

Make any other repairs (if other codes are present) to make sure that other codes are not sources of the trouble code P0340. Check your camshaft position sensor’s voltage, ground, and signal readings with a multimeter. Check out this video for a visual reference on how to check it using your multimeter.