How can you test a camshaft position sensor?

There are different ways to test a camshaft position sensor, depending on the type and the tools available. The most common types of camshaft position sensors are magnetic (or inductive) and Hall effect sensors. Magnetic sensors have two wires, while Hall effect sensors have three wires. To test a camshaft position sensor, you will need a multimeter, a scanner, or an oscilloscope.

Check the electrical diagnosis errors with the crankshaft sensor. If you have any DTC related these errors. Check signal profile

Don’t t neglect checking of base timing or timing adjustment. If you have a circuit/range/performance fault it could be just that, out of position. If the ECU doesn’t differentiate between the two then it could be either issue. I have also seen a sensor rotate out of position and measure at an 11° angle from 0° leading to the assumption the engine was out of time. Check basics and then look at the less likely possibilities.

If I start checking a CMP sensor, I must assume that there is an issue related to engine running characteristics or a MIL. I would check these: 1. Check the wiring diagram and make sure no other fault present in the components who shares ground or supply. 2. Make sure the Vref & grounds are stable. 3. If scope is available, best way to check is to scope the signal and compare it with workshop manual reference or a known good car with respect to CKP. 4. For intermittent faults I would do a wiggle test with scope connected.

If I need to check the camshaft position sensor, I will start with: -Checking DTCs: The Diagnostic Trouble Codes (DTCs) will provide more specific information about the nature of the problem, helping the technician pinpoint issues with the camshaft position sensor or related components. -Checking Vbat and GND: The physical connection between the sensor and Vbat/GND needs to be good. If possible, check if these values are stable using an oscilloscope. -Checking the electric signals: The camshaft sensor can be either magnetic or Hall Effect, but both types provide an electric signal to the Engine Controller. These signals can be tested with an oscilloscope.

In my experience verify sensor is fully plugged in.Check pin tension. Use a graphing multimeter to initially check the sensor pattern.Then if needed utilize a multi channel lab scope to check sensor pattern.And always before you start use a wiring diagram to understand the circuit.

When possible, observe, running scan tool data, utilizing a high-quality scanner, preferably the OEM scan tool. Some provide waveform graphing. Modern scan data is fast and reliable and can help quickly rule out other possibilities.

Use an oscilloscope backprobing on the CMP signal wire and I backprobe at the PCM connector for the CMP signal wire. This way I can see if the signal is reaching the PCM and if it matches. Found a few wiring harness issues this way and also PCM issues too.

during the sensor inspection, make sure to check the connector's integrity by examining the pins for any signs of corrosion. Also, verify if the sensor's sealing gasket is in good condition to prevent water or contaminant infiltration. When examining the cable harness, carefully follow its path and look for any pinch points or abrasions that could compromise wire insulation. A thorough visual inspection of the sensor and its surroundings may reveal additional clues, such as oil traces, indicating potential leaks to address. Don't forget to consult the manufacturer's specifications to ensure the sensor is correctly positioned and oriented. All these checks will contribute to a more comprehensive assessment of the crankshaft position sensor.

One of the ways to know if the sensor works well even if we have a good diagnostic machine we can do the test with the diagnostic device to know if the sensor is working properly or not

With the ignition turned on (but the engine off), probe the sensor's terminals using the multimeter leads. There should be a voltage signal. The exact voltage will depend on your vehicle make and model, so consult the service manual for specifications.

Remove the spark plugs and insert a long rod through number 1 spark plug hole, with a socket and ratchet on the crankshaft pulley turn the engine by hand feeling for number 1 piston reaching top dead centre (rod will be pushed up and stop before moving down again), check the pulley timing mark and rotate to align it accurately. It's best to only turn the engine in its working direction, a little tweak backwards is ok.

The sensor should have at least 3 terminals. Measure the resistance of each combination of terminals. None of them should have a short circuit. Most cars have two sensors and usually, both of them don't go bad. You may compare the results of the two sensors.

Check the resistance drop & continuity across the terminals. If there is no continuity or no difference in resistance, then the sensor could be faulty. An OBD test may also confirm.

A pico scope can be used to measure the current or voltage produced. Most Pico scopes come with a characteristic graph for a particular sensor in the software of the instrument.

Use a multimeter to measure the voltage and resistance. Check for any physical damage or corrosion. Perform a visual inspection. Use an OBD-II scanner to retrieve any error codes related to the camshaft position sensor. Remove the sensor from the vehicle. Measure the resistance between the two connector terminals of the sensor, (terminals 1 and 2). If measured value is not within 1-4 kohms, replace the sensor.

Follow the diagnostic procedure(s) in the Service Manual I wrote for them. Understand the operation of the camshaft sensor detection system first, before inventing tests and checks “because they always work like this.”

I'd like to further add to the guidances by experts above. It all depends on the code thrown by the Engine ECU. Whether it's implausible, or voltage too high or too low, open circuit or short circuit etc Focusing on the type of code will reduce the time for diagnosis. Yes, replacing the sensor is the easiest and time saving way, but if it is not the sensor, apart from the wiring, other possibilities are 1) The air gap between the sensor tip and the toothed wheel 2) The toothed wheel itself, broken teeth or it's mounting 3) ECU itself I might have missed something, experts are welcome to add to it.

I fine monitoring the cams and cranked data on the scan tool or Use an oscilloscope to verify the timing. I feel the oscilloscope is the best way.

First of all I checked the DTCs relataed to the cam sensor. Then visually check is there loose connector, broken wires, or broken sockets. After that check the wire connections using wiring diagrams. If you use a scope you can diagnose the sensor wave form and can identify its bad or good. Some times timing issues causing to generate cam sensor DTCs. It's better to check timing as well.