The crank sensor on your 4.6L or 5.4L Ford pick up (SUV or car) is a two wire type crank sensor that you can easily and accurately test with a multimeter in Volts AC mode.
You don't need a scan tool to test the Ford 4.6L, 5.4L crankshaft position sensor (although a scan tool is a must have tool now-a-days).
This article will walk you thru' the whole thing step by step.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar El Sensor De La Posición Del Cigüeñal (Ford 4.6L, 5.4L) (at: autotecnico-online.com).
Important Tips And Suggestions
TIP 1: The crank sensor is located on the timing chain cover. More specifically, it's located to the right (passenger side) of the crank pulley and behind the A/C compressor.
TIP 2: It's very important that the battery on your Ford car (pick up or SUV) must be fully charged for this test. The battery must have enough reserve power to crank the engine easily for several seconds.
TIP 3: You'll need to jack up the vehicle to gain access to the crank sensor. Use a jack stand to hold the car up in the air. Do not trust the jack! Wear safety glasses to protect your eyes from falling debris. Think safety all of the time!
TIP 4: When the crank sensor goes bad, you'll get a no-spark no-start condition. So, if you're getting spark from the ignition coil pack or the Coil-On-Plug ignition coils.. the crank sensor is good and this test will not help you.
Since so many things can cause a ‘cranks but does not start’ condition, the following tutorial may give you some more diagnostic/troubleshooting insights:
How Does The Crank Sensor Work?
The crank sensor is one of the most critical components to get the engine in your Ford car (pick up, SUV, van) started. Since it provides the signal the PCM needs to start injecting fuel and start creating spark.
Here are some specifics of the crankshaft position sensor:
The 4.6L, 5.4L crank sensor is a two wire variable reluctance sensor. What this means is that:
- It doesn't need an external power source or a Ground source (like in a 3 wire type Hall Effect sensor).
- The crank sensor creates its own signal (AC Volt signal).
Coil Pack Ignition System: If your specific Ford vehicle has an ignition control module (4.6L coil pack vehicles):
- Once the engine starts to crank, the crank sensor produces a crank signal.
- The crank sensor signal is sent directly to the ignition control module.
- Once the ignition control module gets the crank sensor signal:
- The ignition module starts to activate both coil packs.
- Once the coil packs are activated, they start creating spark for each cylinder.
- The ignition module also creates a PIP signal which is sent to the PCM (Powertrain Control Module = Fuel Injection Computer).
- The PIP (Profile Ignition Pickup) signal is the one that the PCM uses to start activating the fuel injectors.
- And so, with the coil packs creating spark for each cylinder and the PCM activating the 8 fuel injectors, the engine in your Ford vehicle starts.
Coil-On-Plug (COP) Ignition System: If your specific Ford vehicle does not use an ignition control module and is the Coil-On-Plug ignition system type:
- The crank sensor signal is sent directly to the PCM.
- The PCM, once it gets the crank sensor signal:
- The PCM activates the Coil-On-Plug ignition coils to start sparking.
- The PCM activates the fuel injectors.
- So, with both fuel and spark being fed to each engine cylinder, the engine in your Ford car (or pick up, van, SUV) starts.
In the next section, I'll go into some of the symptoms of a bad crank sensor...