2018-2020 Subaru BRZ No-Start & Keyless Entry Problems: A Guide to the Vehicle Control Module

Symptoms of a Failing Vehicle Control Module

A failing Vehicle Control Module in a Subaru BRZ can cause frustrating and intermittent issues that often mimic other problems, like a weak battery. The most common failures are related to the car not recognizing the key or refusing to start.

1. Engine Will Not Crank or Start

The most serious symptom is a no-start condition where the engine does not crank at all. You will typically be able to turn on the accessory power—the radio and dashboard lights will illuminate—but pressing the start button with the clutch (or brake for automatic models) depressed does nothing. This often happens intermittently at first before becoming a persistent problem.

2. 'Key Not Detected' Message or Blinking Key Light

The dashboard may display a "Key Not Detected" message, even when the key fob is inside the vehicle. You might also see the small green key icon on the instrument cluster blink instead of staying solid when you press the clutch, indicating the car is not recognizing the immobilizer chip in the key fob.

3. Inconsistent Key Fob Function

While the door locks may still work, the push-to-start function may fail. This happens because the module is unable to complete the security handshake required to start the engine, even if it can receive the simpler lock/unlock signal.

4. Associated Diagnostic Trouble Codes (DTCs)

A professional scan tool that can read body codes is necessary to properly diagnose this module. Common codes pointing to a VCM or related security system failure include:

• B1100: Integ. Unit System Error (Internal module failure)
• B1401: M Collation NG (Immobilizer-related malfunction)
• B1410: Transponder Communication Abnormal (Failure to communicate with the key)
• B1411: Immobilizer Antenna Abnormal
• B1500: Keyless UART Com. Malfunction (Communication circuit error)
• U0140: Lost Communication With Body Control Module

Known Issues, TSBs, and Recalls

While there are no recalls or Technical Service Bulletins (TSBs) that specifically target the 2018-2020 BRZ Vehicle Control Module for high failure rates, two official recalls for these model years are worth noting:

• NHTSA Recall 21V587000: Affects 2018-2019 BRZ models. The low-pressure fuel pump may fail, causing the engine to stall while driving. This is a separate issue from a no-crank condition caused by the VCM.
• NHTSA Recall 18V935000: Affects 2018 BRZ models. A software glitch in the audio system could cause the rearview camera display to remain blank. Dealers can reprogram the unit to fix this.

Programming and Installation Requirements

There is no DIY or onboard method to program this module. You have two main options for programming:

1. Subaru Dealership: A dealership has the factory-required tools and software (like the Subaru Select Monitor) to program the new module to the vehicle.
2. Automotive Locksmith: Many professional locksmiths have specialized equipment that can communicate with Subaru's security systems to program keys and modules, often at a lower cost than the dealer.

When replacing the module, it must be programmed to the car's immobilizer system and have the keys registered to it. In some cases, such as an 'all keys lost' scenario, other related modules like the steering lock module may also need to be replaced or reprogrammed.

Buying a Used Vehicle Control Module

Purchasing a used OEM Vehicle Control Module is a cost-effective way to solve a failure, as new aftermarket units are not readily available and a new OEM module is expensive. Here’s what to look for:

• Match the Part Number Exactly: You must match the OEM part number 88281CA340. While other modules may look similar, they may have different software or hardware for other trim levels or model years.
• Check for Physical Damage: Inspect the module for any signs of water intrusion, corrosion on the pins, or cracks in the plastic casing. These are common causes of electronic failure.
• Source from a Reputable Seller: Buy from a recycler that offers a warranty and guarantees the part is in good working condition. A low-mileage donor vehicle is always preferable.
• Remember Programming Costs: Factor in the cost of professional programming when buying a used module. The part itself may be inexpensive, but it is useless without being properly synced to your vehicle.

Cost Comparison

The total cost of replacement includes the part itself and the labor for installation and programming.

Frequently Asked Questions (FAQ)