The crankshaft position (CKP) sensor, on the 1998-2011 4.0L V6 Ford Ranger (Mazda B4000), is a simple two-wire variable reluctance sensor. It can easily be tested with a multimeter and in this tutorial I'll show you how.
With your test results you'll be able to quickly and easily find out if it's good or bad.
NOTE: You can find the 1997-2010 4.0L Ford Explorer (Mercury Mountaineer) CKP sensor test here:
- How To Test The CKP Sensor (1997-2010 4.0L Ford Explorer And Mercury Mountaineer) (at: troubleshootmyvehicle.com).
Contents of this tutorial:
APPLIES TO: This tutorial applies to the following vehicles:
- 4.0L V6 Ford Ranger (OHV and SOHC): 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011.
- 4.0L OHV V6 Mazda B4000: 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009.
OHV: Over Head Valve.
SOHC: Single Over Head Camshaft.
The 1991-1997 4.0L Ford Ranger (Mazda B4000) CKP test tutorial is here:
Important Tips And Suggestions
TIP 1: The CKP sensor is located right behind the crankshaft pulley.
TIP 2: The battery in your Ford Ranger (Mazda B4000) must be fully charged before you begin the CKP sensor test.
TIP 3: You'll need to jack up the vehicle to access to the CKP sensor. Use jack stands to hold it up in the air. Don't trust a jack! Be careful and think safety all the time.
TIP 4: Before you start the CKP sensor test, check that all six spark plug wires are delivering spark to the spark plugs. 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 one cylinder, the CKP sensor is good, and this test will not help you.
If your 4.0L Ford Ranger (Mazda B4000) is experiencing an intermittent no-start problem, consult the next section (Symptoms Of A Bad CKP Sensor).
TIP 5: This tutorial does not cover any remove and replace instructions for accessing or replacing the CKP sensor. You'll need a repair manual for them (or Google).
Symptoms Of A Bad CKP Sensor
The crankshaft position sensor generally fails in one of two ways:
- A complete failure of the CKP sensor. In this scenario, the CKP sensor stops functioning (forever).
- An intermittent failure of the CKP sensor. In this scenario, the CKP sensor works fine most of the time but now and then it doesn't.
If you suspect that the CKP sensor is malfunctioning intermittently, and causing an intermittent no-start problem, you'll need to test it when the engine doesn't start.
If this isn't possible, I recommend that you replace it with a new one (without testing it). Especially since the CKP sensor isn't an expensive ignition system component.
If the problems get solved, awesome! If it doesn't, you've at least eliminated the CKP sensor as the cause of the intermittent no-start problem.
Where To Buy The CKP Sensor And Save
The crankshaft position sensor isn't an expensive component. The following links will help you to comparison shop and save a few bucks on known automotive brand CKP sensors:
Not sure if the CKP sensor fits your particular 4.0L Ford Ranger (Mazda B4000)? Don't worry, once you get to the site they'll make sure it fits by asking you the specifics of your particular Ford vehicle. If it doesn't fit, they'll find you the right CKP sensor.
Testing The CKP Sensor Signal With A Multimeter
The crankshaft position sensor produces an AC voltage as the engine is cranking or running.
When the engine is cranking, you'll see an AC voltage between 0.5 and 1.2 Volts AC.
If the CKP sensor is bad, it will not produce an AC voltage output.
IMPORTANT: This test is done with the CKP sensor connected to its electrical connector.
CAUTION: The engine has to be cranked to test the CKP sensor's AC voltage output. Be careful and take all necessary safety precautions.
Let's get started:
- 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.
Let's interpret your test results:
CASE 1: The multimeter registered the indicated AC voltage with the engine cranking. This test result indicates that the CKP sensor is good.
Since your Ford Ranger (Mazda B4000) cranks but does not start, take a look at the following tutorial for more testing suggestions:
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 4.0L Ford Ranger (Mazda B4000) Tutorials
You can find a complete list of 4.0L Ford Ranger (Mazda B4000) tutorials in this index:
Here's a small sample of the tutorials you'll find in the index:
- Fuel Pressure Specifications (1991-2011 4.0L Ford Ranger And Mazda B4000).
- How To Test Engine Compression (1991-2011 4.0L Ford Ranger And Mazda B4000).
- How To Test For A Blown Head Gasket (1991-2011 4.0L Ford Ranger And Mazda B4000).
If this info saved the day, buy me a beer!
