Subaru CVT Transmission Diagnostics for Noise and Repairs

Subaru CVT Transmission Diagnostics

If noise continues while FWD is active, the CVT assembly most likely needs replacement.

The Techline continues to receive calls from Technicians regarding CVT repairs. A lot of questions involve what is an applicable repair inside the CVT? This information can be found in Subaru Technical Information System. Other concerns include noises and a binding/shudder feeling. Whenever attempting to diagnose a CVT issue, the tires should be confirmed to be within specification. As little as a 1/4” difference in circumference can cause issues. Subaru recommends using a rope tape measure. If unavailable, you can use a piece of rope and standard tape measure. Wrap the rope around the center of the tread on each tire, mark it with a marker and measure the difference of markings.

After the tires are confirmed to be within specification, move on to confirming the condition with the CVT in Front-Wheel-Drive mode. In this mode, the duty solenoid for the All-Wheel-Drive is turned off.

This mode is achieved using a scan tool. Once activated, look for a change in the condition. For example, the customer may state the vehicle is binding on turns. Tires are within specification so, FWD mode is activated to diagnose further. This would indicate an issue in the AWD system transfer clutches, which is repairable. Another example, the customer may say a noise is in the CVT. With FWD mode is activated, if the sound goes away, it may be repairable and the AWD system should be inspected. If the noise continued while FWD is active, the CVT assembly would most likely need replacement. FWD mode should be used anytime a CVT issue is being diagnosed.

If issues continue after verifying the tires are within specification and using FWD mode, use Subaru Select monitor to retrieve a drive file. Hitting the Enter button when the issue occurs will put a mark in the file.

You May Also Like

Air Ride Suspension Diagnostics

The key to understanding the embedded logic of air ride systems is using service information.

Air ride systems can control vehicle ride height, passenger comfort and improve handling. How they operate and work with the rest of the systems on the vehicle is part of their control system’s embedded logic. There are three main edicts written in this programming: preserve the compressor; keep the vehicle level; and keep the vehicle safe.

Brake Rotor FAQ

Here are the answers to our frequently asked questions regarding brake rotors.

Catalytic Converter Replacement

Converters must be certified and labeled with the correct codes that are stamped into the shell when replacing.

Integrated Wheel Ends

The leading cause of IWE failure is water finding its way into the vacuum lines under the hood and in the wheel well.

Axle Torque Procedures

Guessing the correct torque setting is a bad idea.

Other Posts

Checking The Auxiliary Water Pump

A car or truck comes into the shop with a complaint of poor heater performance. The issue may be the auxiliary water pump.

Tech holds up heater core
Fuel Pressure Diagnostics

Direct injection pressure is measured with sensors, and the signals are used to determine pump speed and/or volume.

Protecting Carbon Fiber Wheels During Service

Carbon fiber wheels are so delicate, cleanliness is next to godliness when mounting and demounting them.

Updating Your TPMS Tools Regularly Matters

You can ensure your read is accurate by updating your tool regularly.