How To Check If Variable Valve Timing Solenoid Is Bad On Your Car


Do you want to know how to check if your variable valve timing solenoid is bad on your car? In this article, I am going to show you how to inspect a variable valve timing solenoid also referred to as a variable valve timing oil control valve, and how to know if it’s bad.

The variable valve timing solenoid sends information to the vehicle’s computer to determine ignition timing and adjust valve lifter operation. This part activates when the vehicle is pulling additional weight, traveling uphill, or when the gas pedal is quickly pushed down.

A bad variable valve timing solenoid will show error codes P0010 P0011 P0012 P0013 P0014 P0015 P0020 P0021 P0022 P0023 P0024 P0025 P0028 P1349 when scanned with a diagnostic scanner.

Here is a step-by-step guide on how to check if your variable valve timing solenoid needs replacement.

How To Check If Variable Valve Timing Solenoid Is Bad On Your Car

The variable valve timing solenoid becomes faulty over time. Sometimes, cleaning can be the solution. However, if the valve is too far gone, you will need to replace it.

In this article, I will provide you with a step-by-step guide on how to check if a variable valve timing solenoid is bad on your car.

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1. Required tools for the job

  • Gloves
  • Safety goggles
  • 10mm socket
  • Diagnostic tool
  • Digital voltmeter

2. Scan your vehicle for error codes

How To Check If Variable Valve Timing Solenoid Is Bad On Your Car

A faulty variable valve timing solenoid can cause a check engine light. To determine that indeed the VVTS is igniting the check engine, you will need to scan your vehicle with a diagnostic scanner.

A variable valve timing solenoid can be faulty due to not receiving the proper voltage, being worn out, being coated with varnish, dirty or low oil in the engine, or even from a dirty clogged variable valve timing solenoid filter screen.

When the variable valve timing solenoid goes bad, a series of error codes such as P0010 P0011 P0012 P0013 P0014 P0015 P0020 P0021 P0022 P0023 P0024 P0025 P0028 P1349 will show during the scanning.

If you do not have a diagnostic scanner, you can order one on amazon.com or take your vehicle to an auto parts store which will normally perform this service for free.

3. Locate the variable valve timing solenoid

How To Check If Variable Valve Timing Solenoid Is Bad On Your Car

The variable valve timing solenoid is usually located at the front of the engine on the pulley side somewhere below the valve cover. The location will depend on the car’s make and model.

4. Unplug the electrical connection

To inspect the operation of the variable valve timing solenoid, you will need to first unplug the electrical connection attached to it. The electrical connection is not secured with any bolts. You just need to pull it out.

5. Turn the ignition key

Next, get behind the wheel and turn the ignition key in the ON position without starting the vehicle. You will need to have electrical power running to the variable valve timing solenoid in order to check it.

6. Test the voltage

Take a digital voltmeter and set it to DC volts. Touch the two test leads to the two electrical connections. You can order a digital voltmeter on amazon.com. If there is no voltage during the testing, you will need to check for shorts and the wiring.

However, if there is a reading, that means that your variable valve timing solenoid is getting electrical power and you can move to the next step.

7. Remove the variable valve timing solenoid

How To Check If Variable Valve Timing Solenoid Is Bad On Your Car

You will need to remove the variable valve timing solenoid to further inspect its operation. It is usually held by one 10mm bolt. Once the bolt is removed, you can remove the VVTS by twisting it back and forth as you pull it straight out with your hand.

8. Test the operation using the car battery

8. Test the operation using the car battery

Next, we’re going to use the battery on the vehicle to test the variable valve timing solenoid.

Take two alligator clip test leads and attach them to the two electrical connections on the variable valve timing solenoid. Then, take the other ends of the alligator clips attach one to the negative battery connection, and touch and release the other one on the positive battery connection.

At this point, the variable valve timing solenoid should move freely back and forth. If it does not move back and forth freely then it might need to be replaced. However, if your VVTS is operating, move on to the next step.

9. Measure the coil resistance

To measure the coil resistance of your variable valve timing solenoid, you need to set your digital voltmeter on the 200 ohms setting and place your two probes on the two electrical connections.

In the owner’s manual, you will find the ohms range for your coil. If the reading is not within the acceptable range, you will need to replace the variable valve timing solenoid.

10. Manually check the movement of the VVTS

In the last step, you will need to check the variable valve timing solenoid manually. Just grab something like a knife and try to move the valve. Make sure that it feels smooth back and forth.

If the valve is heavily coated with varnish from not changing your oil regularly, then you can soak the front end of the valve in a cleaner. If the valve is still not moving freely after being clear, you will need to replace it.

Will a bad variable valve timing solenoid cause a misfire?

A faulty variable valve timing solenoid will cause the engine to misfire or appear to stumble when the vehicle is loaded with extra weight, climbing hills, or when you apply quick pressure to the gas pedal for instant acceleration. This is often caused by an electrical issue with the switch and not always the switch itself.

In Conclusion

A variable valve timing solenoid is an important part of the engine. If you suspect that your VVT solenoid has gone bad, you can follow the steps above and diagnose the condition of the part.

Before replacing your VVT solenoid, I suggest that you first try and clean it. If you are still experiencing some issues even after the cleaning, it is time to replace your VVT solenoid.

Car Care Hacks

Hi there. I am a certified Automotive Service Excellence (ASE) mechanic since 2018 and a car detailer for 10 years.

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