This article will help you to troubleshoot the Chrysler 2.7, 3.3L, 3.5L crank sensor (or code: P0320) with a simple but very accurate test using only a multimeter in Volts DC.
In case you're wondering if the crank sensor can be tested with a simple multimeter resistance test? The answer is No, since it's a Hall Effect type sensor. The good news is that the test you'll learn here is easy to do and you'll get an accurate result that will either condemn the crank sensor as the cause of the No Start or exonerate it.
Here are the contents of this article at a quick glance:
- CRANK SENSOR TEST 1: Verifying the Crank Sensor Signal with a Multimeter.
- CRANK SENSOR TEST 2: Verifying the crank sensor Has Power
- CRANK SENSOR TEST 3: Verifying the Crank Sensor's Ground.
- Crank Sensor Working Theory.
- Related Test Articles.
This article covers vehicles from Chrysler, Dodge, Eagle, and Plymouth. To see if this article applies to your specific vehicle, look for the box (on the column on the right) titled ‘Applies To:’, and click on the ‘next >>’ link to scroll.
CRANK SENSOR TEST 1: Verifying the Crank Sensor Signal with a Multimeter
The very first thing you'll do is to confirm that the crank sensor is creating a crank position signal.
Now, just to give you a little background info on how the crank sensor works: The PCM (Powertrain Control Module= Fuel Injection Computer) provides it with Power and Ground and also a 5 Volt feed on the crank signal circuit. The crank signal, if it's working correctly, will pull down this voltage (5 V) down to 0.3 Volts or so as the engine cranks (or runs).
It's this On (5 Volts) and Off (0.3 Volts) Signal that you'll be testing for with the help of the following test steps:
Disconnect the ignition coil pack from its electrical connector to disable the ignition system. This is important! Do not proceed with the test without first unplugging the ignition coil pack.
Locate the crank sensor's connector and unplug it from the crank sensor. Now, remove some of the plastic wire loom protector and/or the black electrical tape that shields the three wires of the crank sensor to gain comfortable access to the three wires it protects.
When done removing some of this black electrical tape, reconnect the connector back to the crank sensor.
Place the multimeter in Volts DC mode and with a wire-piercing probe or an appropriate tool, connect the RED multimeter test lead to the wire identified with the number 1 in the image viewer.
To see what a what wire piercing probe tool looks like, click here: Wire Piercing Probe.
Remember that the crank sensor must remain connected to its electrical connector.
Ground the BLACK lead of the multimeter to a good ground point on the engine (or preferably on the Battery Negative Terminal).
When everything is set up, turn the Key On and then turn the crankshaft pulley by hand (using the appropriate tools of course) in a clock-wise direction while you keep your eyes on the multimeter.
IMPORTANT: Do not use the starter motor to crank the engine, since this will defeat the accuracy of this test.
If the crank sensor is working correctly, the multimeter will register an On/Off voltage of 5 Volts DC. On is when the multimeter displays 5 Volts DC and off is 0.5 Volts DC. The key to seeing this voltage change is to turn the crankshaft pulley slowly and steadily.
OK, let's turn the page and read how to interpret the multimeter test results you just obtained...
continued from page 1 ...Alright, let's find out if you have a BAD crank sensor on your hands or not. Choose from the CASES below that best match your specific results:
CASE 1: The multimeter registered the On/Off 5 Volts DC as the crankshaft pulley was hand-turned: This result indicates that the crank sensor is creating a good crank signal and is working fine.
CASE 2: The multimeter DID NOT register the On/Off 5 Volts DC as the crankshaft pulley was hand-turned: This is not good. The sensor should have produced the indicated On/Off 5 Volt Signal. But before we condemn the crank sensor as BAD, you need to verify that it's getting power and ground.
The next step is to check that the crankshaft position sensor is getting power. This comes in the form of either 5 Volts or 8 Volts, depending on how old your specific Chrysler (or Dodge or Plymouth or etc.) is. The PCM (Powertrain Control Module=Fuel Injection Computer) is the one that provides these 8 Volts to power the crankshaft position sensor.