How To Test The CMP Sensor (1994-1997 3.3L V6 Chrysler, Dodge, And Plymouth Minivan)

Testing the camshaft position (CMP) sensor, on the 1994-1997 3.3L V6 minivan is actually easier than you might think.

Plus, there's no need for a scan tool or any other expensive diagnostic gear —just a multimeter and a little patience.

I've broken it all down into clear, easy-to-follow steps to help you figure out whether the sensor is good or faulty.

APPLIES TO: This tutorial applies to the following vehicles:

• 3.3L V6 Chrysler Town & Country: 1996, 1997.
• 3.3L V6 Dodge Caravan: 1996, 1997.
• 3.3L V6 Dodge Grand Caravan: 1996, 1997.
• 3.3L V6 Plymouth Voyager: 1994, 1995, 1996, 1997.
• 3.3L V6 Plymouth Grand Voyager: 1994, 1995, 1996, 1997.

OTHER CMP SENSOR TESTS:

• How To Test The CMP Sensor (1990-1993 3.3L V6 Chrysler, Dodge, And Plymouth Minivan).
• How To Test The CMP Sensor (1998-2000 3.3L V6 Chrysler, Dodge, And Plymouth Minivan).

Symptoms Of A Bad CMP Sensor

If the CMP sensor in your mid-'90s 3.3L V6 Chrysler, Dodge, or Plymouth minivan is acting up, you may see one or more of the following symptoms:

• No-start condition: The engine cranks normally but never actually fires up.
• Hard to start: Extended cranking before the engine finally catches and runs.
• Unexpected stalling: The engine may shut off randomly —at idle or while moving.
• Engine running rough: Misfires, vibrations, and uneven idle are common side effects when the sensor is failing but not completely dead yet.
• Poor throttle response: Acceleration may feel sluggish and unresponsive.
• Check engine light with Code 54 (OBD I) or P0340 (OBD II): The PCM logs this code when it doesn't receive CMP sensor signal.

How The CMP Sensor Works

The CMP sensor in this generation of 3.3L V6 minivans is a Hall-Effect type sensor that delivers crucial camshaft position data to the PCM. It has three wires: power, Ground, and signal.

In a nutshell, here's how it works when you crank and start the engine:

• The CMP sensor receives power from the PCM, which is in the form of 8 Volts DC through the orange (ORG) wire.
• Ground for the CMP sensor is supplied by the black with light blue stripe (BLK/LT BLU) wire, also from the PCM.
• As the engine spins, the sensor produces a square wave signal that rapidly switches between two voltage levels.
  • This ON/OFF signal is sent to the PCM via the tan with yellow stripe (TAN/YEL) wire.

This signal has two distinct voltage states:

• During the ON state, the voltage spikes to 5 Volts.
• In the OFF state, the voltage drops down to around 0.3 to 0.5 Volts.

This ON/OFF signal allows the PCM to calculate camshaft position in real time for proper fuel and spark control.

Should I Just Replace The CMP Sensor Without Testing It?

Truth is, a lot of mechanics and DIYers just replace the CMP sensor outright —and most of the time, that solves the issue.

There's nothing wrong with that, especially since the CMP sensor is affordable and easy to replace.

If you're thinking of skipping the testing and jumping straight to replacing it, take a look at the part links below to score a good deal.

But if you'd rather confirm the problem first, I'll walk you through all the tests step-by-step right here.

NOTE: If you're installing a new sensor or removing and reinstalling the same one, see: Installing The CMP Sensor: Air Gap Clearance.

Where To Buy The CMP Sensor And Save

The following links will help you comparison shop for the camshaft position sensor:

CMP Spacer: Air Gap Spacer

NOTE: If you're installing a new sensor or removing and reinstalling the same one, see: Installing The CMP Sensor: Air Gap Clearance.

Camshaft Position Sensor Connector Pinout

CMP Sensor Circuits
Terminal	Wire	Description
1	Orange (ORG)	8 Volts DC
2	Black with light blue stripe (BLK/LT BLU)	Ground
3	Tan with yellow stripe (TAN/YEL)	CMP Sensor Signal

TEST 1: Testing The CMP Signal With A Multimeter

We're going to begin by checking if the camshaft position sensor is alive and outputting the expected signal.

We'll do this by slowly turning the engine by hand and monitoring the sensor's voltage output with a multimeter.

I want to emphasize this because it's crucial for getting an accurate reading on your multimeter: you can't use the starter motor to turn the engine. You need to use a ratchet and socket on the crankshaft pulley so the voltage pulses from the CMP sensor can be seen clearly.

Also, this signal test is done with the CMP sensor still connected —you'll need to back probe the connector or use a wire-piercing tool to tap into the signal wire. You can see an example of this tool here:

• Wire Piercing Tool.

CAUTION: You may need to lift the front of your van to safely access the crankshaft pulley bolt. If you do, place the vehicle on jack stands. Don't trust the jack alone!

OK, let's get'er done:

1. 1

   Unplug the ignition coil from its electrical connector.
   
   It's a safety must —ensures the engine doesn't start during testing.

2. 2

   Put your multimeter in Volts DC mode.

3. 3

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

4. 4

   Tap into the signal wire with the red multimeter test lead.
   
   NOTE: The CMP sensor must remain connected to the engine wiring harness pigtail connector.
   
   Use a back probe or piercing probe on the CMP sensor's signal wire, and attach the red lead of the meter to it.

5. 5

   Switch the key to ON. Don't start the engine.
   
   This energizes the CMP sensor.

6. 6

   Turn the crankshaft by hand.
   
   Use a ratchet (and socket) and slowly rotate the crankshaft pulley clockwise —take it slow for an accurate reading.

7. 7

   The voltage reading should switch between 5 Volts and 0.3–0.5 Volts.

Let's take a closer look at what this test is telling us:

CASE 1: The ON/OFF voltage signal is present. Great news —your CMP sensor is doing its job.

Getting a repeating ON/OFF voltage (5V and ~0.3V) means the CMP sensor is alive and kicking. It's generating an usable signal, and that means it's also getting the power and Ground it needs from the PCM.

CASE 2: No signal appears. Something's not right.

Before moving on, verify that your test connection setup is solid —especially probe connections and wire contact.

Still nothing? We need confirm whether the CMP sensor is being powered with 8 Volts. Head over to: TEST 2: Making Sure The CMP Sensor Is Getting 8 Volts.