2017 Subaru WRX & WRX STI Body Control Module: Programming, Problems, and Replacement

Symptoms of a Failing Body Control Module

A failing Body Control Module in a 2017 Subaru WRX or WRX STI can cause a wide range of confusing electrical problems. Because the BCM controls so many different systems, symptoms can seem random and unrelated. Owners may notice one or more of the following issues:

• Erratic Electronics: Power windows that don't open or close, door locks that act on their own, or interior dome lights that flicker or stay on are common signs.
• Lighting Problems: Headlights or taillights may not turn on, or they might stay on and refuse to turn off. The turn signals might also behave erratically.
• Key Fob and Security Issues: The keyless entry remote may stop working, or the car's alarm system might trigger for no reason. In severe cases, the BCM can fail to recognize the key's transponder chip, leading to a no-start condition.
• Parasitic Battery Drain: One of the most common symptoms is a battery that dies overnight. A faulty BCM may fail to go into "sleep mode" when the car is off, continuing to draw power and draining the battery.
• Dashboard Warning Lights: A malfunctioning BCM can cause multiple, unrelated warning lights to appear on the instrument cluster, such as for the ABS or airbag system, even if those systems are working correctly.

Associated OBD-II Codes

While many BCM issues won't trigger a standard "Check Engine" light, a professional scan tool that can read body codes may reveal specific trouble codes. Look for codes in the "B" (Body) or "U" (Network Communication) series. Specific codes related to a Subaru BCM (or BIU) failure include:

• B1012 / B1013 / B1014: These codes relate to power supply issues for the BIU (Battery Backup, Ignition Power, ACC Power).
• P1572 / P1574: These codes indicate a failure in communication between the key and the immobilizer unit, which is managed by the BCM.
• U-Series Codes (e.g., U122E): These codes indicate a loss of communication between the BCM and other modules in the vehicle, which can be a sign of BCM failure.

Known Issues, TSBs, and Recalls

As of early 2026, there are no active safety recalls for the Body Control Module on the 2017 Subaru WRX or WRX STI.

However, there is a relevant warranty extension to be aware of. Subaru issued a notice for the Data Communication Module (DCM) on 2017-2018 WRX models, extending the warranty to 8 years or 100,000 miles. A faulty DCM can cause a parasitic battery drain, a symptom often mistaken for BCM failure. If you are experiencing a dead battery, it is worth having a Subaru dealer investigate if the DCM is the cause, as the repair may be covered.

Replacement and Programming Requirements

Replacing the BCM in a 2017 WRX or WRX STI is not a simple plug-and-play job. Programming is absolutely required for the new module to function.

Programming Options

1. Subaru Dealer Programming: A Subaru dealership can install and program a new BCM using their proprietary Subaru Select Monitor (SSM) software. This process involves registering the new module to the car, setting vehicle-specific parameters, and registering all existing keys to the new immobilizer. Be aware that many dealers are unwilling or unable to program a used BCM supplied by a customer.
2. Module Cloning Service: A more cost-effective option, especially when using a recycled part, is a BCM cloning service. This involves sending your original BCM and a compatible used donor unit to a specialist. They will read the key, VIN, and immobilizer data directly from your old module's memory chip and write it onto the donor module. The cloned BCM then becomes a direct, plug-and-play replacement, requiring no further programming. This is often the best path for DIY repair.
🎬 See: How a Subaru BIU cloning service works

Replacement Procedure Overview

The BCM is located inside the cabin, in the driver's side footwell, up under the dashboard. While a video for a 2016 Crosstrek shows a similar location, the exact procedure may vary slightly.

1. Disconnect the negative battery terminal and wait at least 15 minutes.
2. Remove any lower dash panels or trim necessary to access the module. This is typically in the area above the pedals.
3. The BCM is a black plastic box with several large electrical connectors. It is often held in place by clips or a few small bolts.
4. Carefully disconnect all electrical connectors. They have release tabs that must be pressed.
5. Remove the BCM from its mounting bracket.
6. Installation is the reverse of removal. Ensure all connectors click securely into place.

Buying a Used Body Control Module

Purchasing a used OEM Body Control Module is an excellent way to save money, but careful verification is essential. Given the programming requirements, you are not just buying a part; you are buying a part that needs to be made compatible with your car.

• Match the Part Number Exactly: The only compatible part number for the 2017 WRX and WRX STI (without smart key) is 88281VA450. Do not purchase a module with a different part number, even if it looks identical.
• Inspect for Damage: When the part arrives, inspect it for any signs of physical damage, especially corrosion on the pins or water marks on the case. Water intrusion is a common cause of failure for interior electronics.
• Plan for Programming: Before you buy, have a plan for programming. Either contact a cloning service and confirm they can work with this part number, or speak with an independent shop that has Subaru programming capabilities. Do not assume you can install it and drive to the dealer for programming, as the car will not start.
• Why Used OEM is a Good Choice: For a complex electronic module like this, a used OEM part is often more reliable than a new, unproven aftermarket unit. The cloning process makes a used OEM module a viable and affordable solution.

Cost Comparison

The cost to replace the BCM can vary significantly based on the part source and programming method.

Frequently Asked Questions (FAQ)