2019-2020 Subaru Forester ECM: Programming, Immobilizer, and Replacement Guide
Everything you need to know about diagnosing, replacing, and programming the Engine Control Module on the fifth-generation Subaru Forester.
- A replacement ECM for a 2019-2020 Forester MUST be reprogrammed by a dealer or specialist to work with the vehicle's immobilizer.
- You must match the OEM part number on the replacement ECM exactly to your original unit.
- Symptoms of failure are broad and can include a no-start condition, stalling, poor performance, and multiple dashboard warning lights.
- Buying a used ECM can save significant money, but you must factor in the mandatory cost of professional programming.
Known Issues, TSBs, and Recalls
While there are no widespread, major recalls specifically for ECM failure on the 2019-2020 Forester, Subaru has issued several Technical Service Bulletins (TSBs) that involve reprogramming the ECM to fix software-related issues. These are not recalls but are official procedures for dealers to resolve known problems.
- TSB 09-112-23: Released in January 2024, this bulletin provides new ECM reprogramming files to address falsely set Diagnostic Trouble Codes (DTCs) P0016, P0017, P0018, and P0019, which relate to camshaft and crankshaft position correlation.
- TSB 09-75-21: This bulletin addresses DTC P0128 (Coolant Thermostat/Engine Coolant Temperature Below Regulating Temperature), which could be set during long periods of downhill driving. A software update for the ECM resolves this issue.
- TSB WUU-06R: While not for the Forester, this service program for the 2019-2020 Ascent and 2020 Legacy/Outback highlights a potential ECM software issue where incorrect learning of the accelerator position could disable the Vehicle Dynamics Control (VDC) system, illuminating multiple warning lights. This demonstrates the complexity of Subaru's ECM software during this period.
An earlier recall (WRE-21) for 2017-2019 Impreza and 2018-2019 Crosstrek models involved an ECM issue that could keep the ignition coil powered after the engine was off, potentially causing a short circuit. While this did not directly affect the Forester, it points to the critical nature of the ECM's software and hardware integrity.
Symptoms of a Failing ECM
An ECM can fail in many ways, leading to a wide range of symptoms. Because the ECM controls so many systems, its failure can sometimes be misdiagnosed as a bad sensor or other component.
- Check Engine Light: This is the most common symptom. A failing ECM can trigger a host of codes, sometimes a long list all at once.
- Engine Performance Issues: You may experience stalling, rough idle, engine misfires, hesitation, or a sudden loss of power. Drivers have reported stalling at traffic lights and sudden deceleration.
- No-Start Condition: The engine may crank but refuse to start, or it may not crank at all.
- Poor Fuel Economy: A sudden, unexplained drop in gas mileage can be a sign that the ECM is no longer managing the air-fuel mixture correctly.
- Multiple Warning Lights: A failing ECM can cause a cascade of errors, leading to multiple warning lights on the dashboard, such as for the VDC, EyeSight, and automatic transmission. 🎬 See what happens when multiple Subaru warning lights illuminate
- Transmission Problems: The ECM communicates with the Transmission Control Module (TCM). A faulty ECM can lead to rough or improper shifting.
Warning: A failing ECM is not just an inconvenience; it can be a serious safety issue. A vehicle that stalls or loses power unexpectedly in traffic can lead to a dangerous situation.
Buying a Used Engine Control Module (ECM)
Purchasing a used OEM ECM is a cost-effective alternative to a brand-new unit, but it requires careful attention to detail to ensure compatibility and proper function.
1. Match the Part Number EXACTLY
This is the most critical step. The part number on the replacement ECM must be an exact match to the one in your vehicle. Subaru uses several part numbers for this generation of Forester, including 22765AL820, 22765AL821, 22765AL822, and 22765AN461. Even a slight variation can mean the unit has different software or hardware intended for another trim level or model year, rendering it incompatible. Do not rely on visual similarity; physically check the label on your original ECM and the used unit.
2. The Immobilizer and Programming Problem
A used ECM for a 2019-2020 Forester is NOT a plug-and-play part. The ECM is a key component of the vehicle's anti-theft immobilizer system. It is electronically 'married' to other modules in the car, like the Body Control Module (BCM) and the keys. Simply swapping the ECM will result in a no-start condition because the immobilizer system will not recognize the new module.
Pro Tip: To avoid programming issues, some specialized services can 'clone' the data from your original ECM to the replacement unit. This involves transferring the VIN, immobilizer data, and other vehicle-specific settings. This is only possible if your original ECM is still readable. If it's completely dead, this option is off the table.
3. Reprogramming is Required
If you install a used ECM, it MUST be reprogrammed to your vehicle's VIN and synchronized with the immobilizer system. This procedure typically requires a Subaru dealer or a well-equipped independent shop with a J2534 pass-thru device 🎬 Watch: Using a J2534 device for Subaru diagnostics and access to Subaru's diagnostic software. Many locksmiths and general mechanics will not have the necessary tools or subscriptions to perform this task. Always factor the cost of programming into your budget.
Cost Comparison
The cost of replacing an ECM can vary significantly based on the source of the part and the labor involved.
| Item | Estimated Cost | Notes |
|---|---|---|
| New OEM ECM | $650 - $1,200 | Price from a Subaru dealership. This does not include labor or programming. |
| Used OEM ECM | $50 - $200 | Price from online marketplaces and salvage yards. Requires programming. |
| Remanufactured ECM | $160 - $350 | Repaired and tested units. May come with a limited warranty. Still requires programming. |
| Shop Labor (Replacement) | $100 - $200 | The physical swap is relatively quick, often taking an hour or less. |
| Shop Labor (Programming) | $150 - $600 | This is the cost for a dealer or specialist to program the new or used ECM to the vehicle. |
Frequently Asked Questions (FAQ)
Do I absolutely have to program a replacement ECM?
Yes. For a 2019-2020 Forester, a replacement ECM (whether new, used, or remanufactured) must be programmed to your vehicle. It is linked to the anti-theft immobilizer system. Without programming, the car will not start.
Can my local mechanic or a locksmith program a Subaru ECM?
It depends. While some advanced independent shops and automotive locksmiths have the necessary J2534 equipment and software subscriptions, many do not. A Subaru dealership is the most reliable, though often most expensive, option for programming. Always confirm with the shop that they have specific experience programming modern Subaru ECMs before proceeding.
Where is the ECM located on a 2019-2020 Forester?
The Engine Control Module is typically located in the engine bay for easy access. On many modern Subarus, it is found on the passenger side, near the firewall. The immobilizer 🎬 Watch: How to locate and remove the Forester ECM control unit, a related component, is often located behind the glove box.
Will a used ECM from a car with different options work?
No. It is crucial to match the part number exactly. An ECM from a vehicle with different features (e.g., different trim level, optional equipment) will have different software and calibrations. Using the wrong module can cause system malfunctions or prevent the vehicle from running altogether, even after programming.
Helpful Videos
Technical Specifications
OEM Part Numbers: 22765AL820 22765AL821 22765AL822 22765AL827 22765AN461
Fits 2019-2020 Subaru Forester models with the 2.5L FB25DI engine and an automatic CVT transmission.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Subaru Forester:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Known Issues, TSBs, and Recalls
- Symptoms of a Failing ECM
- Buying a Used Engine Control Module (ECM)
- 1. Match the Part Number EXACTLY
- 2. The Immobilizer and Programming Problem
- 3. Reprogramming is Required
- Cost Comparison
- Frequently Asked Questions (FAQ)
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