How To Test The Crankshaft Position Sensor (1998-2003 5.2L, 5.9L V8 Dodge Ram Pickup)

TEST 2: Making Sure The CKP Sensor Has Power

The crankshaft position (CKP) sensor needs both power and Ground to work right. So, in this section, you'll grab your multimeter and make sure the sensor's actually getting the power it needs.

This power comes in as 5 Volts DC. The PCM sends this voltage when the key's in the ON position (and when the engine's cranking or running too).

An it's the purple with white stripe (PPL/WHT) wire, carrying these 5 Volts to the CKP sensor.

Here's how to run the test:

1. 1

   Disconnect the CKP sensor from the engine wiring harness connector.

2. 2

   Hook the black multimeter lead to the battery's negative (-) terminal.

3. 3

   Set your multimeter to Volts DC mode.

4. 4

   Probe female terminal 1 of the CKP connector with the red multimeter lead.
   
   Make sure this terminal connects to the PPL/WHT wire.
   
   NOTE: You're testing at the engine wiring harness connector —the one with the female terminals.

5. 5

   Turn the key to the ON position —no need to crank the engine.

6. 6

   Your multimeter should show between 4.5 and 5 Volts DC if the PCM's sending power like it should.

Here's how to interpret your test result:

CASE 1: You're getting 4.5 to 5 Volts DC. That means the CKP sensor's getting the power it needs from the PCM.

For our next test, we gotta check if the sensor has a good Ground. Head over here next: TEST 3: Making Sure The CKP Sensor Has Ground.

CASE 2: You're not seeing 4.5 to 5 Volts DC. Double-check your connections and run the test again just to be sure.

If you still don't see 5 Volts, then you've found the problem: the CKP sensor isn't dead —it's just not getting power. Swapping the sensor won't fix the engine no-start issue.

Finding out why the power's missing is outside the scope of this guide, but solving that will get your V8 Dodge Ram back to starting normally again.

TEST 3: Making Sure The CKP Sensor Has Ground

So far, all your CKP sensor tests have confirmed two things:

• TEST 1: The CKP sensor isn't putting out an ON/OFF voltage signal.
• TEST 2: The sensor is receiving 5 Volts DC.

Now, in this final step, you're gonna check if the sensor's getting Ground with a quick and safe voltage test using your multimeter.

The CKP sensor gets its Ground through the black with light blue stripe (BLK/LT BLU) wire, which comes straight from the PCM (the fuel injection computer).

IMPORTANT: The BLK/LT BLU wire connects directly to the PCM —if it touches battery voltage, you'll fry the PCM. So be careful! The test I'm outlining below is 100% safe and won't risk any damage to the circuit or PCM.

Here's what to do next:

1. 1

   Disconnect the CKP sensor from the harness connector.

2. 2

   Attach the red lead of your multimeter to the positive (+) battery terminal.

3. 3

   Switch your multimeter to Volts DC mode.

4. 4

   Touch the black multimeter lead to the female terminal marked number 2 at the CKP sensor connector.
   
   Make sure you're touching the terminal connected to the BLK/LT BLU wire.

5. 5

   Turn the ignition key to the ON position. No need to crank the engine.

6. 6

   Your multimeter should show a reading between 10 and 12 Volts DC if the Ground circuit's doing what it should.

Here's how to read your results:

CASE 1: You see 10 to 12 Volts DC. That confirms the BLK/LT BLU wire is providing Ground to the CKP sensor like it's supposed to.

If you've nailed down all three tests:

• TEST 1: The CKP sensor isn't sending an ON/OFF 5-Volt signal.
• TEST 2: It's getting proper power (5 or 8 Volts).
• This test: It's also getting good Ground.

Then there's no doubt —the CKP sensor's bad and needs to be swapped out.

CASE 2: You didn't get a reading of 10 to 12 Volts DC. Double-check your test connections and run it one more time to be sure.

If you still don't see 10 to 12 Volts, it means the BLK/LT BLU wire isn't providing Ground. That means the CKP sensor isn't the real problem —the missing Ground is. Fixing that Ground issue is the next step to getting your engine fired back up.

More 5.2L, 5.9L V8 Dodge Ram Pickup Tutorials

You can find a complete list of wiring diagrams and diagnostic tutorials for the V8 Dodge Ram pickup here:

• 5.2L, 5.9L V8 Dodge Ram Index Of Articles.

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

• How To Test The Intake Air Temp (IAT) Sensor (1998-2003 5.2L, 5.9L V8 Dodge Ram Pickup).
• How To Test The MAP Sensor -P0107, P0108 (1997-2003 5.2L, 5.9L V8 Dodge Ram Pickup).
• How To Test The Fuel Pump (1992-2003 5.2L, 5.9L V8 Dodge Ram Pickup).
• Testing The Oxygen Sensors (1996-2003 5.2L, 5.9L V8 Dodge Ram Pickup).