C1741 on 2015-2018 Subaru Outback: VDC Control Module Fault Causes and Fixes

What's Unique About the 2015-2018 Subaru OUTBACK

For this generation of Outback, the C1741 code is rarely due to a hardware failure. Subaru officially acknowledged a sensitivity in the control module's software that could falsely trigger the code under normal driving conditions. Unlike many chassis codes that point to a bad sensor or pump, the primary and most common solution for this specific vehicle is a simple software reprogram performed by a dealer, not a part replacement. The issue is so specific that Subaru issued a detailed Technical Service Bulletin (TSB #06-77-20R) outlining the software fix.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• VDC (Vehicle Dynamics Control) warning lamp is illuminated
• Hill Holder warning lamp is activated
• Hill Holder cancellation alarm sounds
• ABS warning light may also be illuminated
• Multiple warning lights appearing at once after a specific event, like a low-speed slide in snow or a sluggish start.
🎬 Watch: What to do when your Subaru warning lights illuminate

Most Likely Causes

1. VDCCM Software Requires Update 🔴 High Probability Subaru issued TSB #06-77-20R specifically for this issue, where the control module's logic is overly sensitive and misinterprets slight, residual brake pedal pressure as a fault.
   How to confirm: A Subaru dealer or a shop with a Subaru Select Monitor (SSM) or equivalent advanced diagnostic tool can check the current software calibration ID (CID) of the VDCCM and compare it against the updated files mentioned in the TSB.
   Typical fix: Reprogramming (reflashing) the Vehicle Dynamics Control Module with the updated software provided by Subaru. This is a labor-only procedure.
   Est. part cost: $0

Rare But Worth Checking

• Failing Vehicle Dynamics Control Module (VDCCM): This should only be considered if the code returns after the official software update has been correctly applied. A complete hardware failure of the module is uncommon but possible. A Reddit user with a 2015 Forester was quoted $2690 for a VDC unit replacement due to a failing internal motor relay, which presents a similar cluster of warning lights.
• Low Battery Voltage: The TSB explicitly notes that when battery voltage drops below a certain threshold during engine start, the VDCCM can judge the condition as a power supply irregularity. This specifically triggers the blinking Hill Holder lamp and cancellation alarm, alerting the driver the system is off. While it may not set C1741 every time, ensuring the battery and charging system are healthy 🎬 See how a simple battery fix can clear electronic faults is a critical first diagnostic step, as low voltage can cause a variety of electronic issues.

Diagnosis Steps

1. Verify the presence of code C1741 using an OBD-II scanner capable of reading Chassis (C-codes).
2. Check for any other accompanying codes, particularly C1531, which is part of the same TSB.
3. Test the battery and charging system. Ensure battery voltage is stable and above the minimum threshold, especially during startup. A weak battery can cause various electronic module faults.
4. Consult with a Subaru dealership or qualified independent shop to determine if TSB #06-77-20R applies to your vehicle's VIN and has been performed.
5. If the TSB has not been performed, have the VDCCM reprogrammed with the latest software. The procedure requires a stable power supply (like a Midtronics DCA-8000) to be connected to the vehicle to prevent module failure during the flash.
6. If the code persists after the reprogram, further diagnosis of the VDCCM hardware and its associated wiring and connectors is required. This would be an uncommon outcome.

Parts You'll Likely Need

• Vehicle Dynamics Control Module & Hydraulic Unit (VDCCM&H/U) (OEM #27596AL06A (superseded by 27596AL06B for non-EyeSight models); 27596AL07A (superseded by 27596AL07B for EyeSight models).) — This part is only needed in the rare event that the software reprogram does not fix the issue and the module itself is diagnosed as faulty. 🎬 Watch this walkthrough on how to swap a Subaru control unit It is not the first-line fix.
  Trusted brands: Subaru (Genuine)
  OEM price range: $730-$900.
  Aftermarket price range: Not typically available; used units may be found for less.

Related Codes That Often Appear With This One

• C1531 — This code is mentioned in the same Technical Service Bulletin (#06-77-20R) and is triggered by a similar scenario involving slight brake pedal pressure after releasing the Electric Parking Brake (EPB).

Technical Service Bulletins (TSBs) & Recalls

• 06-77-20R: Describes the condition, cause (software logic), and solution (reprogramming) for DTCs C1741 and C1531 on 2015-18 Legacy and Outback and 2016-18 WRX models.

Platform-Specific Known Issues

• A known software issue documented in TSB #06-77-20R causes the VDCCM to be overly sensitive to driver brake pedal input, leading to false fault codes.
• Owner experiences on forums like Reddit confirm that a cluster of lights (VDC, ABS, Hill Holder) can appear suddenly, often related to low voltage or events that challenge the traction control system, pointing towards the sensitivity of these electronic modules.

Mechanic-Grade Diagnostic Values

• VDCCM Power Supply Voltage at Connector — expected: 10 – 15 V. Failure: Voltage below 10V or above 15V indicates a power supply or charging system issue that must be corrected before module diagnosis.
• Reprogramming Power Supply Voltage — expected: A steady 13.5 Volts. Failure: Voltage rising above 14V during the procedure will cause the flash to abort.

Scan Tool Commands That Help

• Subaru Select Monitor (SSM): Each System Check -> VDC System -> Getting of vehicle information — This function is used to read the current Calibration Identification Number (CID) of the VDCCM. This ID is compared against the list of new software versions in TSB #06-77-20R to confirm if the update is required.
• Subaru Select Monitor (SSM): FlashWrite — This is the specific application used to reprogram (reflash) control modules, including the VDCCM, with the updated software files (pak files) provided by Subaru to resolve the C1741 fault.
• Subaru Select Monitor (SSM): Clear Memory Mode — This function should be performed after a successful repair or software update to erase the stored C1741 and any related DTCs from the module's memory.

Wiring & Ground Locations

• VDCCM&H/U — In the engine compartment, on the left (driver's side) front, mounted below the main fuse box.. This is the physical location of the control module that stores the code and requires reprogramming. Access is needed to check its main connector for power, ground, and CAN bus integrity if the software update fails to resolve the issue.
• VDCCM Connector - Pin 28 (Power) — Pin 28 on the main harness connector for the VDC Control Module.. This is the main power supply pin for the module. A voltage check here (referenced to ground) confirms if the module is receiving proper power from the vehicle's electrical system.
• VDCCM Connector - Pin 25 (Ground) — Pin 25 on the main harness connector for the VDC Control Module.. This is the primary ground pin for the module. All voltage checks should be referenced to this pin, and a resistance check from this pin to a known good chassis ground should show near-zero ohms.

OEM Part Supersession History

• 27596AL06A → 27596AL06B — Internal revision by the manufacturer. Often done to improve reliability or accommodate small production changes.
  Heads up: Applies to models WITHOUT EyeSight. The new part (B) replaces the old part (A).
• 27596AL07A → 27596AL07B — Internal revision by the manufacturer.
  Heads up: Applies to models WITH EyeSight. The new part (B) replaces the old part (A).

Model Year Variations Within This Range

• 2018-2019: The Subaru Outback received a mid-generation refresh for the 2018 model year. While the C1741 software issue and TSB apply through 2018, some underlying components and part numbers for other systems may differ from the 2015-2017 models. However, for this specific fault, the cause and repair procedure remain consistent across the entire 2015-2018 range.