How To Test The Camshaft Position Sensor (1992-1997 3.9L Dodge Dakota)

TEST 2: Making Sure The CMP Sensor Has Power

If the camshaft position sensor is stuck producing a single voltage value as you turn the engine (TEST 1), then the next step is to make sure it's getting power from the fuel injection computer.

On the 1992-1995 3.9L Dodge Dakota, power is in the form of 8 Volts DC and are supplied by the orange (ORG) wire of the connector.

On the 1996-1997 3.9L Dodge Dakota, power is in the form of 5 Volts DC and are supplied by the violet with white (VIO/WHT) wire of the connector.

NOTE: Avoid probing the front of the female terminal with your multimeter test lead or you run the risk of damaging the terminal. Use a back-probe on the back of the connector or use a wire-piercing probe on the wire.

These are the test steps:

1. 1

   Disconnect the CMP sensor from its connector.

2. 2

   Place your multimeter in Volts DC mode.

3. 3

   Turn the key on but don't crank or start the engine.

4. 4

   Connect the red multimeter test lead (using the appropriate tool) to the power wire identified with the number 1 in the photo above.
   
   On the 1992-1995 3.9L Dodge Dakota this is an ORG wire.
   
   On the 1996-1997 3.9L Dodge Dakota this is a VIO/WHT wire.

5. 5

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

6. 6

   Your multimeter should read:
   
   7 to 8 Volts DC (1994-1995 3.9L Dodge Dakota).
   
   4 to 5 Volts DC (1996 3.9L Dodge Dakota).

Let's examine your test result:

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

The next and last test is to make sure that the BLK/LT BLU wire is feeding the CMP sensor with Ground. Go to: TEST 3: Making Sure The CMP Sensor Has Ground.

CASE 2: The CMP sensor is not getting power. Without this voltage the camshaft position sensor will not produce a CMP voltage signal.

The most likely cause of these missing 8 or 5 Volts is an open-circuit problem in the ORG or VIO/WHT wire between the CMP sensor's connector and the fuel injection computer's connector.

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.

TEST 3: Making Sure The CMP Sensor Has Ground

If you've reached this point, the results of TEST 1 and TEST 2 have confirmed that:

• The camshaft position sensor is not creating an ON/OFF signal (TEST 1).
• The camshaft position sensor is getting 8 or 5 Volts DC (TEST 2).

In this test section, we're now gonna' make sure that the CMP sensor is getting Ground from the black with light blue stripe (BLK/LT BLU) wire.

In the photo above, the black with light blue stripe (BLK/LT BLU) wire is labeled with the number 2.

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

NOTE: Avoid probing the front of the female terminal with your multimeter test lead or you run the risk of damaging the terminal. Use a back-probe on the back of the connector or use a wire-piercing probe on the wire.

These are the test steps:

1. 1

   Disconnect the CMP sensor from its connector.

2. 2

   Place your multimeter in Volts DC mode.

3. 3

   Turn the key on but don't crank or start the engine.

4. 4

   Connect the black multimeter test lead (using the appropriate tool) to the Ground wire identified with the number 2 in the photo above.
   
   This wire is the BLK/LT BLU wire of the connector.

5. 5

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

6. 6

   Your multimeter should read 10 to 12 Volts DC if the BLK/LT BLU wire is providing Ground.

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

CASE 1: Ground is present in the BLK/LT BLU wire. This is the correct and expected test result.

You can now conclude that the camshaft position sensor is bad and needs to be replaced if you have:

• Confirmed the ON/OFF voltage signal IS NOT present in the tan with yellow stripe (TAN/YEL) wire as you manually turned the engine (TEST 1).
• Confirmed that the camshaft position sensor is getting power (TEST 2).
• Confirmed that the camshaft position sensor is getting Ground (this test section).

CASE 2: Ground is NOT present in the BLK/LT BLU wire. Without Ground the camshaft position sensor will not produce a CMP voltage signal.

The most likely cause of this missing Ground is an open-circuit problem in the BLK/LT BLU wire between the CMP sensor's connector and the fuel injection computer's connector.

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.

More 3.9L Dodge Dakota Tutorials

You can find a complete list of 3.9L Chrysler and Dodge tutorials in this index:

• Chrysler 3.9L Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

• How To Test The Starter Motor (1991-1995 3.9L Dodge Dakota).
• How To Test Engine Compression (1993-2003 3.9L Dodge Dakota).
• How To Test For A Blown Head Gasket (1993-2003 3.9L Dodge Dakota).
• Engine Management Sensor Circuit Diagram (1994-1995 3.9L V6 Dodge Dakota).