The crankshaft position (CKP) sensor on the 1997-2010 4.6L Crown Vic or Grand Marquis isn't difficult to test. The best part is you don't need any expensive diagnostic tools to do it.
While a scan tool is a must-have tool, you don't need one to test the CKP sensor. All we'll use is a simple multimeter.
In this tutorial, I'll explain how to test it with step-by-step instructions. I'm also gonna show you where to buy a new one if you need one. Let's get started!
Contents of this tutorial:
APPLIES TO: This tutorial applies to the following vehicles:
- 4.6L Ford Crown Victoria: 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011.
- 4.6L Mercury Grand Marquis: 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011.
E-Series Vans: You can find the CKP sensor test for the E-Series vans here:
F-Series Pickups: You can find the CKP sensor test for the F-Series pickups here:
- How To Test The CKP Sensor With A Multimeter (1997-2010 4.6L, 5.4L V8 Ford F150, F250, F350) (at: easyautodiagnostics.com).
Important Tips And Suggestions
TIP 1 -Battery Fully Charged: Testing the CKP sensor requires cranking the engine with the starter motor (without starting it). So a fully charged battery is super important for the test. A weak battery can slow down the engine cranking, which can lead to inaccurate CKP sensor test results on the multimeter.
TIP 2 -Use Jack Stands: You'll need to lift the vehicle to access the CKP sensor and test it. Safety first! Use jack stands to support the vehicle, never rely solely on the jack.
TIP 3 -Wear Safety Glasses: Protect your eyes from debris, dirt, or fluids that could leak while working under your car.
TIP 4 -Keep Hands And Tools Clear Of Moving Parts: Be aware of belts, pulleys, and fans that are spinning as the engine is cranked (to perform the CKP sensor test). Keep your hands and tools away from these moving parts to avoid injury.
TIP 5 -Check For Spark: Before testing the CKP sensor, check for spark in a couple of spark plug wires (1995-1997 engines) or ignition coils (COP) using a spark tester.
If there's spark in even one spark plug wire or ignition coil, you can conclude the CKP sensor is likely functioning properly.
Here's why: A faulty CKP sensor can cause a no-spark problem from the ignition system, causing the engine not to start. If there's spark, the CKP sensor is likely not the culprit of the engine's no-start problem.
Symptoms Of A Bad CKP Sensor
A bad crankshaft position sensor will prevent the engine from starting. Even though the engine cranks, it won't fire up because there's no spark and fuel injection.
Here are some of the specific symptoms you'll see of a bad CKP sensor:
- No Spark: The ignition system isn't creating nor delivering spark to the spark plugs.
- No Fuel Injection: The fuel injectors aren't activated.
- Diagnostic Trouble Codes (DTCs): In some cases, the engine computer might store specific trouble codes related to the CKP sensor.
- P0315: CKP Sensor Relearn Problem.
- P1309: Misfire Monitor Disabled.
- Check Engine Light (CEL): The CEL may come on to warn you about a faulty CKP sensor next time the engine starts if the PCM detects the CKP sensor malfunction.
It's important to note that the crankshaft position (CKP) sensor can fail intermittently. In other words, it might work most of the time, but occasionally stops sending a signal to the fuel injection computer.
An intermittent CKP sensor failure can cause the engine to suddenly run rough, stall unexpectedly or even fail to start entirely, even though the engine will usually run fine most of the time.
Ideally, the fuel injection computer would detect the missing CKP sensor signal and trigger a diagnostic trouble code (DTC) and illuminate the CEL. However, in these cases, the DTC isn't registered and the CEL doesn't come on despite the CKP sensor issue.
Should I Test The CKP Sensor Or Just Replace It?
Replacing the CKP sensor is a common approach for most folks, even for professional technicians/mechanics (despite the possibility of testing it first).
These are the main reasons for replacing it instead of testing it:
- Cost: The CKP sensor is inexpensive, making its outright replacement seem like a pretty good option.
- Time: Testing the CKP sensor, especially for intermittent issues, can be a time-consuming and frustrating process.
- Accessibility: Due to its location, reaching the sensor and its wires (to set up the test) can be a challenge.
- Lack of Diagnostic Expertise: Those unfamiliar with the CKP sensor testing procedures or interpreting its test results may feel more comfortable replacing the sensor as the go-to solution.
So in summary, replacing the CKP sensor from the get-go can be the faster solution considering factors like cost, time, access to tools, and troubleshooting skills. 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 want to test it, I'll show you how using a simple multimeter. Go to: Testing The CKP Sensor Signal With A Multimeter.
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 Crown Vic or Mercury Grand Marquis? 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 works like a magnet since it's a reluctance type sensor. As such, it creates a small AC voltage signal when a metal object (the crankshaft's pulse ring) gets close to it (like a magnet attracting something).
A good working CKP sensor will produce a measurable AC voltage signal that can be checked with a multimeter in AC Volts mode.
To test the CKP sensor, we need to crank the engine (without starting it) while having our multimeter connected to the CKP sensor's wires, and look for an AC voltage reading.
If the sensor is functioning properly, the multimeter should show an AC voltage between 0.5 and 1.2 Volts.
NOTE: The ignition system must be disabled to prevent the engine from starting during the test.
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 Crown Vic And Grand Marquis Tutorials
There are quite a few 4.6L Ford Crown Victoria (Mercury Grand Marquis) 'how to' tutorials and wiring diagrams in this index:
E-Series Vans: You can find all of the available tutorials and wiring diagrams for the 4.6L and 5.4L V8 E-Series vans in this index:
F-Series Pickups: You can find all of the available tutorials and wiring diagrams for the 4.6L And 5.4L V8 F-Series pickups in this index:
- 4.6L, 5.4L Ford F150, F250, And F350 Index of Articles (at: easyautodiagnostics.com.com).
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