How to Test a VVT Solenoid with a Multimeter

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By the early 1190s, nearly all automotive manufacturers had a thriving variable valve timing (VVT) system in production. These systems provide higher and greater performance at higher RPM. 

What is a VVT System?

A VVT helps to offer better power delivery, smoother idling for daily needs, enhanced fuel economy, and excellent emissions control. Your VVT system needs a series of various parts to accomplish all of such tasks, which includes the variable valve timing solenoid. 

In a standard engine, valve timing is always fixed when the valves open and close. However, with a modern VVT system, the position of the camshafts can be changed, adjusting valve timing. Having that capability can boost fuel economy, engine performance, or both. 

Numerous parts work together in a standard VVT system. Many cars employ a hydraulically operated actuated system seen at the camshaft’s end to adjust its position and advance or retard valve timing. On the other hand, the VVT solenoid uses oil pressure to trigger the actuator.

Take note that the PCM manages the VVT solenoids based on input from numerous sensors. Normally, there is a single VVT solenoid for every actuator. Other cars only have an actuator on the intake camshaft or the exhaust camshaft, while a few have actuators on both. 

It’s worth remembering that numerous auto manufacturers have diverse naming conventions for their VVT systems. For instance, BMW refers to its system as VANOS, and Ford calls its setup Twin Independent Variable Camshaft or Ti-VCT. 

What is a VVT Solenoid? 

In case you didn’t know yet, the VVT solenoid is in charge of adjusting the position of the engine’s camshafts. It functions on oil pressure and could either retard or advance cam position to offer the proper performance from the engine.

Every camshaft is geared with a VVT solenoid that can change the supply of oil pressure to the camshaft. However, it will still depend on the engine’s load and speed. What if the VVT solenoid suddenly stopped working? In that case, the check engine light will come on, and your engine will function worse. 

It’s worth mentioning that the most typical culprit for VVT solenoid issues is dirty oil, clogging the screen that sits between the VVT pressure switch and the solenoid. Once the solenoid stops working, the VVT system will continue being disengaged. That could significantly affect fuel economy, engine performance, and other things. 

Pay Attention to These Common Problems

What happens when a VVT solenoid starts wearing out or needs some repair? You will find some instances that could lead to total engine failure, but the more typical problems are other signs you need to be aware of. 

Below are the most typical signs and impacts of VVT solenoid problems that you can diagnose by partnering with an auto repair professional. 

  • Check engine light on

Keep in mind that any component is checked and tracked with an engine control computer to ensure everything goes perfectly. If such a crucial solenoid sensor is out of work, expect your computer to alert you by enabling the CEL.

Many of today’s modern cars are managed by an engine control unit or ECU. Also, nearly all of their components are monitored by that ECU. Imagine if one component begins to fail. The ECU will deliver a trouble code, informing the driver with a dashboard warning light.

Once the check engine light appears, that could suggest a failure of a VVT solenoid. Bear in mind that each vehicle manufacturer utilizes numerous codes. That’s why you should call a qualified mechanic to check your car, download the code and identify the root of the issue. 

  • Bad fuel efficiency

Exhaust and intake valves work in time to save fuel consumption with VVT and OCV cooperation. VVT helps guarantee valves open and close at the proper times to improve engine performance and fuel efficiency.

Thus, a bad VVT solenoid tends to lead to lowered fuel economy, as the exhaust and intake valves are not closing and opening at the right times. 

  • The engine is idling rough, and there’s a fluctuation in RPM

VVT might get stuck to function if the OCV is failing to produce enough oil pressure. The engine then begins to idle rough as the VVT fails to start high power at higher RPM. Take note that the VVT system normally doesn’t start until the engine reaches a higher RPM or is introduced to scenarios like driving uphill.

Nevertheless, there’s a possibility it could introduce added engine oil to the VVT gears, particularly if the VVT solenoid malfunctions. That could cause the engine’s rough idling with regard to the RPM fluctuating of the engine. That could lead to engine components wearing down much faster. 

  • Dirty engine oil

VVT solenoids work most efficiently and best when the engine oil is clear and clean of debris or when it has lost some of its lubricity or viscosity. What happens if the engine oils start to clog up with debris or dirt particles? It will likely lead to clogging the passage which runs from the solenoid to the VVT chain and gear.

Have you not been keeping up with your engine oil changes? Your VVT solenoid, gear drive, and chain could all sustain damages. Hence, ensure you always keep up with your oil changes based on the recommendations of your car manufacturer. 

How Do You Test a VVT Solenoid for Its Functionality?

Here’s how you can test your VVT solenoid with a digital multimeter.

  1. First, make sure you unplug the electrical connection connected to it
  1. Turn the ignition key to the on position. Always remember not to start your vehicle. 
  1. Grab your digital multimeter and set it to DC volts. Touch the two test leads to the two electrical connections. 
  1. Do you see voltage? If you didn’t see any voltage, it means you will need to check for shorts and the wiring.

Final Thoughts

Is your car geared with a variable valve timing system? Then it’s essential that it operates as designed for proper fuel efficiency and performance. If your car’s VVT solenoid is malfunctioning or faulty, have it changed as quickly as possible to regain your lost performance!

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