2020-2023 Subaru Crosstrek Telematics Module: Solving Battery Drain and Reboot Loops

Is it a BCM or a DCM? A Critical Distinction

Before diagnosing any issue, it's important to know that the part numbers listed (86222FL141, 86229FL140, 86229FL141) are for the Data Communication Module (DCM), also known as the Telematics Control Unit. This is NOT the Body Control Module (BCM). While the names are similar, they perform very different jobs. The DCM handles STARLINK telematics, while the BCM controls core body electronics like lights and locks. The most common problems associated with this part number—namely battery drain and infotainment reboots—are specific to the DCM.

Known Issues, TSBs, and Warranty Extensions

The most significant known issue with the Subaru DCM is a defect that causes a severe parasitic battery drain. A software glitch or internal memory corruption can prevent the module from entering a low-power 'sleep' mode when the car is turned off. Instead, it remains active, constantly trying to communicate with the network and drawing excessive power (over 300mA), which can drain a new battery in just a few days. This failure also causes the infotainment screen to get stuck in a reboot loop, as it continuously fails to get a response from the frozen DCM.

Subaru has acknowledged this widespread problem on many models by issuing Technical Service Bulletins (TSBs) and extending the warranty on the DCM. While some documents specifically name older Crosstreks or other models like the Outback and Forester, the symptoms described are identical to those experienced by 2020-2023 Crosstrek owners. Owners experiencing these issues, even if out of the standard warranty, should contact a Subaru dealer or Subaru of America, reference the DCM battery drain issue, and inquire about a goodwill repair or warranty extension coverage.

Symptoms of a Failing DCM

A faulty DCM typically presents one or both of the following major symptoms:

• Parasitic Battery Drain: The most common and frustrating symptom. The vehicle's battery dies after sitting for a few days, or even overnight, for no apparent reason. This often leads to owners replacing the battery multiple times, only for the problem to persist because the underlying cause is the faulty DCM.
• Infotainment Reboot Loop: The main center display (head unit) is stuck in a continuous cycle of rebooting. It will show the Subaru STARLINK logo, go blank, and repeat endlessly. This is because the head unit cannot establish a connection with the non-responsive DCM.
• Other Infotainment Glitches: While less common, a failing DCM can also contribute to an unresponsive touchscreen, issues with Apple CarPlay or Android Auto, and random radio behavior.

Diagnosing and Fixing the Problem

You have several options to address a faulty DCM, ranging from a free, temporary workaround to a permanent dealer repair.

Option 1: The Temporary Reset (Battery Disconnect)

Disconnecting the negative terminal of your car's 12-volt battery for at least 20 minutes will force a hard reset of all the vehicle's computers, including the DCM. This will likely stop the infotainment reboot loop and may temporarily resolve the battery drain. However, this is not a permanent fix. The underlying software glitch in the DCM remains, and the problem will almost certainly return.

Option 2: The DIY Workaround (Fuse Pull)

You can completely disable the faulty DCM by pulling its fuse from the interior fuse box (typically located under the driver's side dashboard 🎬 Watch: How to pull the DCM fuse to stop rebooting). Look for a 7.5-amp fuse labeled "DCM". Removing this fuse cuts all power to the module, stopping the battery drain and the reboot loop. The major downside is that on some models, the front speakers and hands-free microphone are routed through the DCM, so pulling the fuse will disable them. Aftermarket bypass harnesses are available for around $80 that can solve this speaker issue.

Option 3: The Official Repair (Dealer Visit)

The only way to permanently fix the issue while retaining all vehicle functions is to visit a Subaru dealership.

1. Software Update: The first step a dealer will take is to apply a software update. This new firmware doesn't fix the DCM itself, but it cleverly reprograms the main head unit to be 'smarter'. Instead of rebooting endlessly when the DCM doesn't respond, the updated head unit will try a few times and then simply ignore it, allowing the infotainment system to boot up and function normally. 🎬 See how a firmware update can fix the reboot loop This often solves the rebooting symptom.
2. DCM Replacement: If the software update does not work or if the parasitic drain continues, it means the DCM has failed internally. In this case, the module must be replaced.

Buying a Used Body Control Module

Purchasing a used DCM can be a cost-effective alternative to a new one, but it comes with important considerations. Used units can be found for under $100 from automotive dismantlers.

• Verify the Part Number: Ensure the part number on the used module exactly matches your original or one of its superseding numbers (e.g., 86229FL141 replaces 86229FL140).
• Factor in Programming Costs: This is the most important step. A used DCM is useless without being programmed to your vehicle. Call local Subaru dealers or qualified independent shops beforehand to get a quote for programming a customer-supplied used module. This cost can range from $150 to over $400, depending on local labor rates.
• Inspect for Damage: When you receive the part, check for any physical damage to the casing or connector pins. Avoid any parts that show signs of water intrusion or corrosion.
• Understand the Risk: You are buying a used electronic part that is known to have a high failure rate. While it may be cheaper, there is a risk it could fail in the same way as your original. However, given the high cost of a new module, a used one plus programming is often still the most economical choice for a full-function repair.

Cost Breakdown

Frequently Asked Questions