2015 Subaru WRX Power Steering Control Module: Failures, Programming, and Replacement

Symptoms of a Failing Power Steering Module

A failing power steering control module can make your WRX difficult and unsafe to drive. Watch for these specific signs:

• Power Steering Warning Light: The most obvious sign is the illumination of the power steering warning light on your dashboard, which looks like a steering wheel with an exclamation point next to it. This light indicates the system has detected a fault.
• Sudden Heavy Steering: The most common complaint is a sudden and complete loss of power assist, making the steering wheel extremely difficult to turn, especially at low speeds. This can be intermittent, coming and going without warning.
• Inconsistent or Jerky Steering: The steering assist may feel unpredictable, sometimes working normally and other times feeling heavy or jerky during a turn.
• Audible Noises: While less common for a module failure, you might hear a buzzing or clicking from the electric motor as it receives erratic signals from the failing control unit.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

As of mid-2024, there are no specific recalls for the power steering control module on the 2015 Subaru WRX. However, Subaru has issued recalls for EPS systems on other models and years, such as the 2019 Forester and Crosstrek, for similar issues like a loss of power steering assist. Additionally, TSB #04-17-17-R was released for a rattling sound from the EPS steering rack, but this is a mechanical issue with the rack itself, not the control module.

Programming and Calibration: The Critical Step

Yes, a replacement Power Steering Control Module must be programmed and calibrated to the vehicle. This is not a plug-and-play part. Several eBay listings for used modules explicitly state that programming is required by a dealer or certified technician. After physical installation, a specialized diagnostic tool, like the Subaru Select Monitor (SSM), is needed to perform several procedures. These may include clearing any stored assist maps from the donor vehicle and performing a zero-point calibration for the steering angle sensor. 🎬 Watch: How to reset the electronic module after replacement Failure to perform this calibration will result in a persistent power steering warning light and a non-functional system. 🎬 See how to reset the power steering warning light While an independent shop with advanced diagnostic tools may be able to perform the calibration, a dealer visit is the most certain method to ensure it is done correctly.

Buying a Used 2015 WRX Power Steering Module

Purchasing a used OEM module is a cost-effective way to repair your WRX, but careful verification is essential.

Compatibility is Key

You must match the part number exactly. The primary OEM part number for this application is 34710VA010. Double-check that the module came from a 2015 WRX with a manual transmission. Using a module from an automatic, an STI, or another Subaru model will not work.

What to Inspect

When buying a used module, visually inspect it for any signs of damage. Check the casing for cracks and ensure all electrical connector pins are straight and free of corrosion. The module is located inside the vehicle, under the dashboard, so it is less susceptible to environmental damage, but always check for signs of water intrusion.

Why Used OEM is a Smart Choice

A used OEM module is often a better choice than a new aftermarket part. OEM parts are designed and tested for your specific vehicle, ensuring proper fit and function. Given the complex programming requirements, a genuine Subaru part is more likely to communicate correctly with the vehicle's other systems after installation. New aftermarket options are scarce, and a new OEM module is significantly more expensive.

Replacement Overview

The power steering control module is located inside the cabin, typically under the driver's side of the dashboard. Replacing it involves removing lower dash panels to gain access, disconnecting the battery, unplugging the electrical connectors, and unbolting the module from its bracket. While the physical swap is straightforward for a DIY mechanic with some experience, the mandatory programming means the job is not complete until the vehicle is connected to a compatible scan tool.

Frequently Asked Questions (FAQ)