How To Test The Camshaft Position Sensor (1992-1995 3.9L V6 Dodge Ram Pickup)

TEST 2: Making Sure The CMP Sensor Has 8 Volts

If in TEST 1 the camshaft position sensor is not creating an ON/OFF voltage signal, then there's a good chance that it's missing 8 Volts.

The wire that supplies 8 Volts to the camshaft position sensor is the orange (ORG) wire of the CMP sensor's 3-wire connector.

In my photo of the connector above, this wire is labeled with the number 1.

So, in this test section, we're going to make sure that the ORG wire has 8 Volts present with the key on engine off (KOEO).

NOTE: Be careful when probing the front of the female terminal with your multimeter test lead or you run the risk of damaging the terminal.

These are the test steps:

1. 1

   Disconnect the CMP sensor from its connector.

2. 2

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

3. 3

   Place your multimeter in Volts DC mode.

4. 4

   Probe the female terminal of the connector that connects to the ORG wire with the red multimeter test lead.
   
   The ORG wire is the one I've labeled with the number 1 in the photo above.
   
   NOTE: This test is done on the engine wiring harness connector that has female terminals.

5. 5

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

6. 6

   Your multimeter should read 7.5 to 8 Volts.

Let's analyze your test result:

CASE 1: The multimeter confirms that the ORG wire has 8 Volts DC. This is the correct and expected test result.

The next and last test is to make sure that Ground is present in the BLK/LT BLU wire of the connector. For this test go to: TEST 3: Making Sure The CMP Sensor Has Ground.

CASE 2: The ORG wire is not providing 8 Volts DC. Without this voltage the camshaft position sensor will not produce a CMP voltage signal.

What's usually behind this lack of 8 Volts is an open-circuit problem in the ORG wire between the CMP sensor connector and the PCM 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

The wire that feeds the CMP sensor with Ground is the black with light blue stripe BLK/LT BLU wire. In the photo above, this wire is labeled with the number 2.

We can easily confirm the presence of Ground in the BLK/LT BLU wire by doing a simple multimeter voltage test.

IMPORTANT: Be careful and don't short the BLK/LT BLU wire to battery power (12 Volts) or you'll fry the fuel injection computer. The multimeter voltage test I'm suggesting below (for testing the presence of Ground in this wire) is a safe and accurate test.

NOTE: Be careful when probing the front of the female terminal with your multimeter test lead or you run the risk of damaging the terminal.

Let's get testing:

1. 1

   Disconnect the CMP sensor from its connector.

2. 2

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

3. 3

   Place your multimeter in Volts DC mode.

4. 4

   Probe the female terminal of the connector that connects to the BLK/LT BLU wire with the black multimeter test lead.
   
   The BLK/LT BLU wire is the one I've labeled with the number 2 in the photo above.
   
   NOTE: This test is done on the engine wiring harness connector that has female terminals.

5. 5

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

6. 6

   Your multimeter should read 10 to 12 Volts.

Let's analyze your test result:

CASE 1: Ground is present in the BLK/LT BLU wire. This is the correct test result and let's you know that the camshaft position sensor is getting Ground.

The camshaft position sensor is bad and needs to be replaced if:

• The camshaft position sensor IS NOT creating an ON/OFF voltage signal (TEST 1).
• The ORG wire is providing the CMP sensor with 8 Volts DC (TEST 2).
• The BLK/LT BLU wire is feeding Ground to the CMP sensor.

CASE 2: Ground IS NOT present in the BLK/LT BLU wire. Without Ground, the camshaft position sensor will not produce an ON/OFF voltage signal.

What's usually behind this lack of Ground is an open-circuit problem in the BLK/LT BLU wire between the CMP sensor connector and the PCM 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 V6 Dodge Ram Pickup Tutorials

You can find a complete list of 3.9L V8 Dodge Ram pickup tutorials and wiring diagrams in this index:

• 3.9L V6 Dodge Ram Pickup Index Of Articles.

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

• How To Test The Fuel Pump (1992-2001 3.9L V6 Dodge Ram Pickup).
• How To Test The Intake Air Temp (IAT) Sensor (1992-1997 3.9L V6 Dodge Ram Pickup).
• How To Test The MAP Sensor (1992-1996 3.9L V6 Dodge Ram Pickup).
• How To Test For A Blown Head Gasket (1989-2001 3.9L V6 Dodge Ram Pickup).