How To Test The Camshaft Position (CMP) Sensor (1997-2001 2.2L Toyota Camry)

Troubleshooting the camshaft position (CMP) sensor on the 1997-2001 2.2L Toyota Camry, to find out if it's good or bad can be easily done with a multimeter.

In this tutorial, I'll explain how to test it step-by-step. With your test results, you'll quickly and easily find out if it's good or bad.

APPLIES TO: This tutorial applies to the following vehicles:

• 2.2L Toyota Camry: 1997, 1998, 1999, 2000, 2001.

Ignition System Tests:

• How To Test The Ignition Coils (1997-2001 2.2L Toyota Camry).
• How To Test The Crankshaft Position (CKP) Sensor (1997-2001 2.2L Toyota Camry).

Wiring Diagrams:

• Ignition System Circuit Wiring Diagram (1997 2.2L Toyota Camry).
• Ignition System Circuit Wiring Diagram (1998-1999 2.2L Toyota Camry).
• Ignition System Circuit Wiring Diagram (2000-2001 2.2L Toyota Camry).

Camshaft Position (CMP) Sensor Basics

In the 1997–2001 2.2L Toyota Camry, the camshaft position (CMP) sensor is a magnetic reluctance sensor, also known as a variable reluctance sensor.

The sensor is located on the passenger side of the cylinder head, right between where the intake manifold bolts to the cylinder and the upper timing belt cover.

It monitors the camshaft's position and rotational speed and sends this important data to your Camry's fuel injection computer. With this info, the computer knows which cylinder is approaching its top dead center (TDC) position on its compression stroke.

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

• The camshaft starts to rotate.
• The CMP sensor detects the passing reluctor teeth and generates an alternating current (AC) signal.
• This signal, along with the CKP sensor's output, is sent to the fuel injection computer.
• The computer uses the data to enable and control ignition timing and fuel injection.
• The engine starts and runs.

Unlike Hall-effect sensors, which require an external power source and produce a digital square wave signal, variable reluctance sensors generate an AC voltage (sine wave) signal independently, without needing an external power source.

As variable reluctance sensor, the CMP sensor's frequency and amplitude signal varies with engine speed. This makes testing the output of the sensor (while cranking the engine) with a fully charged battery a must to achieve the best engine cranking speed and an accurate test result.

Symptoms Of A Bad CMP Sensor

When the camshaft position (CMP) sensor fails on your 1997-2001 2.2L Toyota Camry, it's gonna cause several noticeable symptoms.

The most common symptom is:

• Engine no-start: The engine cranks but fails to start when the CMP sensor has completely failed and no longer produces a signal.

Other common symptoms of a failing CMP sensor include:

• Check engine light: In most cases, a CMP sensor issue will trigger the check engine light, indicating a CMP sensor diagnostic trouble code (DTC) has been set.
• Engine stalling: If the CMP sensor fails intermittently, it can cause a loss of signal, leading to sudden engine stalling while driving or idling.
• Engine misfires or rough idle: Faulty readings from the CMP sensor can disrupt ignition timing, resulting in engine misfires and a rough-running engine.

Keep in mind, these symptoms can also be caused by other issues. That's why testing the CMP sensor's resistance and output (to confirm its condition) before replacing it is a smart way to save both time and money.

Where To Buy The CMP Sensor And Save

The following links will help you comparison shop for the CMP sensor of two well known automotive brands (Standard Motor Products and Delphi):

NOTE: Not sure if the CMP sensor fits your particular 2.2L Toyota Camry? Don't worry. Once you get to the site, they'll ask you for the specifics of your vehicle. If it doesn't fit, they'll find you the right one.

TEST 1: Measuring The Resistance Of The CMP Sensor

The first thing that we're gonna do is check the CMP sensor's internal resistance with a multimeter in Ohms mode.

This will let us know right off the bat if the sensor has an internal short-circuit or open-circuit problem.

If the CMP sensor is OK, its internal resistance should be within the following range:

• Cold: 985 to 1400 Ohms.
• Hot: 1,060 to 1645 Ohms.

NOTE: If you don't have a multimeter, check this one out (it's the one I use): Tekpower TP8268 AC/DC Auto/Manual Range Digital Multimeter with NCV Feature (at: amazon.com).

Let's get testing:

1. 1

   Disconnect the CMP sensor from its engine wiring harness connector.
   
   LOCATION: The CMP sensor's connector is located on the side of the cylinder head facing the engine compartment firewall. It's between where the intake manifold bolts to the cylinder head and the upper timing belt cover. The arrow in image 2 of 2 (in the image viewer above) points to the CMP sensor's location.

2. 2

   Set your multimeter to Ohms mode.

3. 3

   Probe the resistance across the male spade terminals with the multimeter test leads.

4. 4

   The multimeter should register an Ohms value in the indicated range.
   
   Cold: 985 to 1400 Ohms.
   
   Hot: 1,060 to 1645 Ohms.

Let's interpret your test result:

CASE 1: The multimeter registered the indicated Ohms value. This is the correct and expected test result.

Your next step is to test the CMP sensor in action. Go to TEST 2: Testing The CMP Sensor With The Engine Cranking.

CASE 2: The multimeter registered no continuity (infinite resistance). This tells you that the CMP sensor is bad (it has an internal open-circuit problem).

Replace the camshaft position sensor.

CASE 3: The multimeter registered 0 resistance. This indicates the CMP sensor has suffered a short-circuit problem. It needs to be replaced.

TEST 2: Testing The CMP Sensor With The Engine Cranking

With the engine cranking or running, the camshaft position (CMP) sensor generates an AC voltage.

To check for its output AC voltage signal, we'll connect a multimeter (set to Volts AC mode) to the CMP sensor and then crank the engine.

Here's what we can expect:

• Good CMP sensor: Your multimeter will register an AC voltage reading of around 0.4–1.2 Volts AC as the engine cranks.
• Bad CMP sensor: Your multimeter will show zero AC Volts while cranking then engine.

IMPORTANT: The CMP sensor connector is tucked away in the rear of the cylinder head, between where the intake manifold bolts to the cylinder head and the upper timing cover. To connect your test leads to the sensor terminals, I suggest you use some jumper wires with insulated alligator clips. This setup lets you safely read that AC voltage output while cranking the engine. You can see an example of this type of jumper wire (and you can buy them too) here: 10 Pc. And 5 Color Insulated Alligator Clips (at: amazon.com).

NOTE: For the most accurate results, make sure your Toyota Camry's battery is fully charged before running this test.

These are the test steps:

1. 1

   Disconnect the ignition coils from their electrical connectors.
   
   NOTE: This is a safety precaution to keep the engine from starting during the CMP sensor test.

2. 2

   Disconnect the CMP sensor from its electrical connector.

3. 3

   Place your multimeter in Volts AC mode.

4. 4

   Connect the multimeter test leads to the male spade terminals of the CMP sensor's connector with jumper wires with insulated alligator clips.
   
   IMPORTANT: You're probing the male spade terminals of the CMP sensor itself and not the female terminals of the engine wiring harness connector.

5. 5

   Have a helper crank the engine as you observe the multimeter.
   
   CAUTION: Be careful and stay alert as the engine is cranking.

6. 6

   The multimeter should report an AC voltage that will oscillate somewhere around 0.4 to 1.2 Volts AC.

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

CASE 1: The multimeter reported the indicated AC voltage. This test result confirms that the CMP sensor is functioning correctly.

CASE 2: The multimeter reported 0 AC voltage. This test result confirms that the CMP sensor is bad and needs replacement.

More 2.2L Toyota Camry Tutorials

You can find a complete list of 2.2L Toyota Camry tutorials in this index:

• 2.2L Toyota Camry Index Of Articles.

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

• How To Test For A Blown Head Gasket (1990-2001 2.2L Toyota Camry, Celica).
• How To Test Engine Compression (1990-2001 2.2L Toyota Camry, Celica).
• How To Test The Fuel Pump (1996-2001 2.2L Toyota Camry).
• How To Test The TPS With A Multimeter (1997-2001 2.2L Toyota Camry).