TEST 1: Testing The Crankshaft Position Signal

 Testing The Crankshaft Position Signal. How To Test The Crankshaft Position Sensor (1996 2.5L OHV Dodge Dakota)

As the engine turns, the crankshaft position (CKP) sensor creates an ON/OFF voltage signal. For the sake of our testing purposes, ON is when the sensor produces 5 Volts DC and OFF is when the sensor produces 0 Volts DC on its signal wire.

When the CKP sensor fails, it will usually stay stuck producing 5 Volts DC or 0 Volts DC as the engine turns.

So, what we're gonna' do is connect the multimeter to the crankshaft position signal wire and see if these ON/OFF pulses are present (as we manually turn the engine).

NOTE: To get the most accurate test result, you must turn the engine by hand (for example: using a ratchet wrench and appropriate socket on the crankshaft pulley). If you use the starter motor to turn the engine, your multimeter will not be able to read the ON/OFF voltage pulses.

IMPORTANT: The crankshaft position sensor must be connected to its engine harness connector for this test to work. You'll need to connect your multimeter test lead to a back probe or a wire piercing probe to read the crank signal. You can see an example of a wire piercing probe here: Wire Piercing Probe Review (Power Probe PWPPPPP01).

These are the test steps:

  1. 1

    Place your multimeter in Volts DC mode.

  2. 2

    With the red multimeter lead, probe the GRY/BLK wire of the crank sensor connector (on the engine wiring harness).

    The gray with black stripe (GRY/BLK) wire connects to the male terminal labeled with the number 3 in the illustration above.

  3. 3

    Connect the black multimeter lead directly on the battery negative (-) terminal.

  4. 4

    Turn the ignition key to the ON position and turn the engine by hand using the 1/2" ratchet wrench and appropriate socket on the crankshaft pulley. For the accuracy of the test, do not use the starter motor.

  5. 5

    Your multimeter will read an ON/OFF voltage of 5 Volts and 0 Volts (if the crankshaft position sensor is functioning correctly).

    ON is when the multimeter reads 5 Volts DC and OFF is when it reads 0 Volts DC.

Let's take a look at what your crank sensor test result means:

CASE 1: The ON/OFF DC voltage signal is present. This is the correct and expected test result and tells you that the crankshaft position sensor is functioning correctly.

If you have a P0320 trouble code or the engine stalls intermittently (while you're on the road), you could still have a defective crankshaft position sensor on your hands (even though it tested OK at this moment). I suggest taking a look at the following section: Intermittent Failure Of The Crankshaft Position Sensor.

CASE 2: The ON/OFF DC voltage signal IS NOT present. This test result tells you that the crank sensor is defective.

Before you replace it, make sure it's getting power and Ground. For this test go to: TEST 2: Making Sure The Crank Sensor Has Power And Ground.

TEST 2: Making Sure The Crank Sensor Has Power And Ground

How To Test The Crankshaft Position Sensor (1996 2.5L OHV Dodge Dakota)

Before we condemn the crankshaft position sensor as defective, we need to make sure it's getting power and Ground.

Both power and Ground are provided by your 1996 Dodge Dakota's fuel injection computer.

Ground is provided by the black with light blue stripe (BLK/LT BLU) wire of the CKP sensor's engine wiring harness connector. Power is provided by the purple with white stripe (PPL/WHT) wire of the CKP sensor's engine wiring harness connector.

NOTE: The power and Ground tests are done on the engine wiring harness crank sensor connector. This connector has round female terminals. Avoid probing the front of the female terminal.

IMPORTANT: Be careful and don't short the Ground wire to battery power or you'll fry the fuel injection computer. The multimeter voltage test suggested below (for testing the Ground circuit) is a safe and accurate test.

OK, these are the test steps:

  1. 1

    Verify that the PPL/WHT wire that connects to terminal #1 of the connector has 5 Volts DC with the key on but engine off.

    Connect the red multimeter test lead (using the appropriate tool) to the PPL/WHT wire of the engine wiring harness crank sensor harness connector.

    Connect the black multimeter test lead to the negative (-) battery terminal.

    Your multimeter should read 4.5 to 5 Volts DC.

  2. 2

    Verify that the BLK/LT BLU wire that connects to terminal #2 of the connector has Ground with the key on but engine off.

    Connect the black multimeter test lead (using the appropriate tool) to the BLK/LT BLU wire of the engine wiring harness crank sensor harness connector.

    Connect the red multimeter test lead to the positive (+) battery terminal.

    Your multimeter should read 10 to 12 Volts DC.

Let's take a look at what your test results mean:

CASE 1: The crank sensor is getting power and Ground. This is the correct and expected test result.

You can now conclude that the crankshaft position sensor is defective if you have:

  1. Verified that it is NOT producing its ON/OFF signal (TEST 1).
  2. Verified that IT IS getting power and Ground.

If your test results match, then replacing the CKP sensor will solve the no start problem and/or the P0320 trouble code.

CASE 2: The crank sensor IS NOT getting power. This lack of power will stop the crankshaft position sensor from functioning.

Although it's beyond the scope of this tutorial to check for this missing power, your next step is to find out why it's missing and restore it. This should solve the no start problem and/or the P0320 trouble code.

CASE 3: The crank sensor IS NOT getting Ground. This lack of Ground will stop the crankshaft position sensor from functioning.

Although it's beyond the scope of this tutorial to check for this missing Ground, your next step is to find out why it's missing and restore it. This should solve the no start problem and/or the P0320 trouble code.