The crankshaft position (CKP) sensor on the 1997-2010 4.6L and 5.4L V8 Ford F-Series pickups isn't difficult to test. The best part is you don't need any expensive diagnostic tools to do it -just a multimeter.
In this tutorial, I'll explain how to test it and where to buy a new one if needed. Let's get started!
Contents of this tutorial:
APPLIES TO: This tutorial applies to the following vehicles:
- 4.6L Ford F150: 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010.
- 5.4L Ford F250 Light Duty: 1997, 1998, 1999, 2000.
- 5.4L Ford F250 Super Duty: 1997, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010.
- 5.4L Ford F350 Super Duty: 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010.
E-Series Vans: You can find the CKP sensor test for the E-Series vans here:
- How To Test The CKP Sensor With A Multimeter (1997-2009 4.6L, 5.4L V8 Ford E150, E250, E350) (at: troubleshootmyvehicle.com).
Important Tips And Suggestions
TIP 1 -Battery Fully Charged: We'll be testing the CKP sensor while the engine is cranking. So it's important that the battery 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 2 -Use Jack Stands: You'll may need to jack up the vehicle to gain access to the CKP sensor. Use a jack stand to hold the pickup up in the air. Do not trust the jack! Use safety glasses also. Think safety all of the time!
TIP 3 -Wear Safety Glasses: Wear safety glasses to protect your eyes from dirt, debris, or any fluids that might leak while working underneath your vehicle.
TIP 4 -Keep Hands And Tools Clear Of Moving Parts: Be mindful of moving parts such as belts, pulleys, and fans. Keep your hands and tools away from these areas.
TIP 5 -Check For Spark: Before starting the CKP sensor test, it's super important that your first check couple of the spark plug wires (1997-1999 4.6L) or ignition coils for spark with a spark tester. If you get even just one spark plug cable with spark, you can conclude the CKP sensor is OK.
In other words, when the CKP sensor fails, the engine won't start due to a lack of spark to all cylinders. So, if you're getting spark, even if it's just from one spark plug wire or COP ignition coil, the CKP sensor is good and this test won't 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 packs (1997-1999 4.6L V8) or the COP ignition coils aren't going to fire spark to all eight spark plugs.
- No Fuel Injection: The fuel injection computer isn't 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.
I want to point out that the CKP sensor can malfunction intermittently. What I mean is that it'll work fine most of the time but occasionally fails to generate a signal.
This type of CKP sensor malfunction can cause the engine to run rough or not start at all, even though it usually runs fine most of the time.
When the CKP sensor fails to send a signal, the fuel injection computer should ideally register a CKP sensor diagnostic trouble code (DTC) and activate the check engine light the next time the engine starts. Unfortunately, it's rare for the fuel injection computer to actually set a CKP sensor DTC.
Should I Test The CKP Sensor Or Just Replace It?
Many folks, including professional techs and mechanics, choose to replace the CKP sensor immediately instead of testing it when faced with a CKP sensor DTC or symptoms of a faulty sensor (e.g., engine cranking but not starting). Here are the main reasons:
- The CKP Sensor Isn't Expensive: The affordability of a new CKP sensor makes replacing it more appealing than testing it.
- Time Savings: Testing the CKP sensor can be time-consuming, especially if the problem is intermittent and difficult to pinpoint.
- Access: Setting up test connections on the CKP sensor's connector wires can be challenging due to the sensor's location and wiring access difficulties.
For these three reasons many see replacing the CKP sensor as the faster fix.
Ultimately, the decision to replace without testing is influenced by factors like cost, time constraints, tool availability, and 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 pickup? 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.
Testing The CKP Sensor Signal With A Multimeter
The CKP sensor is a reluctance type sensor, which in plain English means that it generates an AC voltage signal as the pulse ring on the crankshaft passes by its tip (while the engine is cranking or running).
As long as the engine is turning over or running and the CKP sensor is functioning correctly, it'll generate an AC voltage signal that you and I can measure with a multimeter (in AC Volts mode).
To check the CKP sensor's functionality, we'll connect a multimeter to its wires and crank the engine (with the ignition system disabled to make sure the engine doesn't start).
If the CKP sensor is working correctly, the multimeter should show an AC voltage signal ranging between 0.5 and 1.2 Volts AC.
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 4.6L, 5.4L Ford F150, F250, And F350 Tutorials
There are quite a few 4.6L, 5.4L V8 F-Series pickup 'how to' tutorials and wiring diagrams you can find here:
F-Series Vans: You can find all of the available tutorials and wiring diagrams for the 4.6L and 5.4L V8 F-Series vans in this index:
- 4.6L, 5.4L Ford F150, E250, And E350 Index of Articles (at: troubleshootmyvehicle.com).
Crown Vic/Grand Marquis: You can find all of the available tutorials and wiring diagrams for the 4.6L V8 Ford Crown Vic and Mercury Grand Marquis in this index:
- 4.6L Crown Victoria And Grand Marquis Index of Articles (at: troubleshootmyvehicle.com).
If this info saved the day, buy me a beer!
