The crankshaft position (CKP) sensor on the 1997-2003 4.2L V6 Ford E150/E250 van is a two-wire reluctance type sensor that's super easy to test.
In this tutorial, I'll explain how to test it and where you can buy a replacement. The really cool thing about this test is that it's done with a multimeter. You don't need any expensive diagnostic equipment—in fact, you don't even need a scan tool.
Contents of this tutorial:
APPLIES TO: This tutorial applies to the following vehicles:
- 4.2L V6 Ford E150: 1997, 1998, 1999, 2000, 2001, 2002, 2003.
- 4.2L V6 Ford E250: 1997, 1998, 1999, 2000, 2001, 2002, 2003.
Important Tips And Suggestions
TIP 1: The CKP sensor is located right behind the crankshaft pulley, since the CKP sensor's reluctor wheel is behind (and part of) the crankshaft pulley.
TIP 2: The CKP sensor's signal is measured while the engine is cranking. To get the most accurate test result, the battery should be fully charged. A low battery will cause the engine to crank slower than normal and you're not gonna see a good CKP sensor signal result on your multimeter.
TIP 3: You'll may need to jack up the vehicle to gain access to the CKP sensor. Use a jack stand to hold the van up in the air. Do not trust the jack! Use safety glasses also. Think safety all of the time!
TIP 4: The first thing you should do, before testing the CKP sensor is checking a couple of the spark plug wires (high tension cables) for spark with a spark tester. Why? Well if even just one spark plug cable has spark, this tells you that the CKP sensor is OK.
In other words, when the crankshaft position sensor goes bad, you'll get a no-spark no-start condition. So, if you're getting spark, even if in just from one spark plug wire, the CKP sensor is good and this test will not help you.
Symptoms Of A Bad CKP Sensor
The most obvious symptom of a bad crankshaft position sensor is an engine that won’t start. Specifically, the engine will crank but not start due to a lack of spark and fuel injection.
Specifically, you'll see:
- No Spark: The ignition coil pack is not going to fire spark to all six spark plugs.
- No Fuel Injection: The fuel injection computer is not going to activate the fuel injectors.
- Trouble Codes: On that rare occasion the PCM stores a CKP diagnostic trouble code (DTC), you'll see one of these:
- P0315: CKP Sensor Relearn Problem.
- P1309: Misfire Monitor Disabled.
- Check Engine Light (CEL): The computer often detects the CKP sensor malfunction, sets a CKP DTC and illuminates the CEL to alert you.
In some cases, it fails intermittently. As in the sensor works fine most of the time but every now and then fails to send a CKP signal to the fuel injection computer.
In such instances, the engine will start and run smoothly for the most part but will either run very rough or fail to start from time to time.
Whenever the CKP sensor fails to create and send its signal, the fuel injection computer should ideally set a CKP sensor diagnostic trouble code (DTC) and illuminate the check engine light the next time the engine starts.
However, even though the fuel injection computer is designed to alert you to a malfunctioning crankshaft position sensor, it doesn't always do so.
Should I Test The CKP Sensor Or Just Replace It?
Most folks, when faced with a CKP sensor diagnostic trouble code (DTC) and symptoms that suggest that the sensor is bad (for example: the engine cranks but does not start), generally choose to replace the sensor without testing it. There are two main reasons for this:
- The CKP Sensor Is Inexpensive: The CKP sensor is a pretty inexpensive component to buy. Its low cost makes it super appealing to simply replace it rather than spending the time and effort to test it.
- Saving Time: Performing the CKP sensor tests can be time-consuming, especially if the problem is intermittent or difficult to replicate. For this reason, for many (including shops), replacing the CKP sensor outright may seem like the quickest solution.
Ultimately, the decision to replace the CKP sensor without testing it depends on factors such as cost, time constraints, and your level of diagnostic expertise. If you want to simply replace the CKP sensor, you can find my recommendations here: Where To Buy The CKP Sensor And Save.
If you test it, then this guide will help you test it using a multimeter (to measure the sensor's output signal) and find out if it's good or bad without having to replace it.
Where To Buy The CKP Sensor And Save
The following links will help you comparison shop for the CKP sensor of known automotive brands -Delphi, Standard Motor Products, and Hitachi (no knockoffs):
NOTE: Not sure if the CKP sensor fits your particular Ford van? Don't worry, once you get to the site they'll make sure it fits by asking you the specifics of your particular vehicle. If it doesn't fit, they'll find you the right CKP sensor.
Is The CKP Sensor's Pulse Ring Damaged?
The CKP sensor is located at the front of the engine, right above the pulse ring behind the crankshaft's vibration damper (also known as the harmonic balancer). The crankshaft pulley, which drives the serpentine belt, is bolted to the dampener (see image above).
Even though the pulse ring is tucked behind the vibration dampener, it's still pretty much out in the open and exposed to the elements.
Since the pulse ring is exposed to the elements, it's not uncommon for its teeth to get damaged, which will cause the CKP sensor to report an erratic CKP signal to the fuel injection computer.
Also, as the engine ages and accumulates thousands of miles, the vibration damper will eventually start to wobble. This too will affect the pulse ring and may cause the CKP sensor to report an erratic CKP signal to the computer.
Before you begin the CKP sensor test in the next section, inspect the CKP sensor's pulse ring for any obvious damage (like missing or bent teeth).
Next, check the vibration dampener for wobble and if it's wobbling (as the engine runs), you've found a possible source of the CKP sensor malfunction.
Testing The CKP Sensor Signal With A Multimeter
As I mentioned at the beginning of this tutorial, the CKP sensor is a two-wire type sensor. This means you can easily test its output signal with a multimeter.
To access the CKP sensor, you'll have to jack up the vehicle (and place it on jack stands).
IMPORTANT: This test is done with the CKP sensor connected to its electrical connector.
OK, these are the test steps:
- 1
Unplug the CKP sensor from its electrical connector.
You may need to remove some of the plastic wire loom protector and/or the black electrical tape that shields/protects the two wires of the CKP sensor. - 2
Connect the red multimeter test lead to one of the two wires of the connector.
IMPORTANT: Make sure your multimeter test leads DO NOT interfere with the crankshaft pulley or the serpentine drive belt, since you'll be cranking the engine in one of the following steps. - 3
Connect the black multimeter test lead to the remaining wire of the connector.
IMPORTANT: Make sure your multimeter test leads DO NOT interfere with the crankshaft pulley or the serpentine drive belt, since you'll be cranking the engine in one of the following steps. - 4
Reconnect the connector to the CKP sensor.
- 5
Turn the multimeter's dial to Volts AC.
- 6
Have your helper crank the engine when the test is set up and you're standing a safe distance from the engine.
- 7
Your multimeter should register an AC voltage between 0.5 to 1.2 Volts AC while the engine is cranking.
When the engine is not cranking, you should see 0 Volts AC.
NOTE: Your multimeter will not register a steady AC voltage. Instead, the reading will fluctuate between 0.5 to 1.2 Volts AC continually as the engine is cranking and only when the engine is cranking.
OK, let's take a look at what your test results mean:
CASE 1: The multimeter registered the indicated AC voltage with the engine cranking. This test result indicates that the CKP sensor is good.
CASE 2: The multimeter DID NOT register the indicated AC voltage with the engine cranking. This test result confirms that the CKP sensor is fried. Replace the crankshaft position sensor.
More 4.2L Ford E150 And E250 Test Tutorials
If this tutorial was helpful, be sure and take a look at all of the 4.2L V6 E150 and E250 diagnostic tutorials in this index:
Here's a sample of the tutorials you'll find there:
- How To Test The Throttle Position Sensor (1997-2000 4.2L V6 Ford E150, E250).
- How To Test Engine Compression (1997-2003 4.2L V6 Ford E150, E250).
- How To Test The Fuel Pump (1997-2000 4.2L V6 Ford E150, E250).
- How To Test For A Blown Head Gasket (1997-2003 4.2L V6 Ford E150, E250).
If this info saved the day, buy me a beer!
