2010-2012 Genesis & Equus Adaptive Headlight (AFLS) Module Failure: Diagnosis and Replacement

Is This a Body Control Module (BCM)?

No. While it may be referred to as a control module, this part (OEM numbers 921703M000, 921703M002) is the Adaptive Front Lighting System (AFLS) Module. It specifically controls the swiveling and auto-leveling headlights. It does NOT control other body electronics like power windows, door locks, wipers, or the radio; those functions are handled by the main Body Control Module (BCM), which is a different part entirely.

Symptoms of a Failing AFLS Module

When the AFLS module fails, you will notice issues confined to the operation of your adaptive headlights. The vehicle will remain drivable, but this important safety feature will be disabled.

• AFLS Warning Light: The most common symptom is an 'AFLS' or similar warning light illuminating or flashing on your instrument cluster.
• Headlights Don't Swivel: The headlights will no longer turn left or right as you steer into corners.
• Headlights Stuck in One Position: The lights may become stuck aimed far to one side, or aimed too high or too low, potentially blinding oncoming drivers or failing to illuminate the road properly.
• No "Self-Test" at Startup: 🎬 Watch: See how the adaptive lighting system operates and calibrates. On many vehicles, the adaptive headlights perform a brief "sweep" up-and-down and side-to-side when you first turn them on. A failed module will prevent this initialization sequence.
• Diagnostic Trouble Codes (DTCs): A scan tool may reveal communication codes (like U0140) or specific AFLS-related faults. For example, if the wrong software is loaded, codes like B1638 (Air-Sus. CAN Signal Timeout) or B1953 (Leveling Sensor signal Fault) may appear.

Known Issues and Vehicle-Specific Fitment

Compatibility is critical for this part. Pay close attention to the specific requirements for your vehicle, as using the wrong module will result in failure.

2010-2011 Hyundai Genesis

• 2010 Model Year Split: For the 2010 Hyundai Genesis, this module (part number 921703M000, later replaced by 921703M001) is only correct for vehicles manufactured on or after October 24, 2009. Vehicles built before this date use a different part.

2011-2012 Hyundai Equus

• 2012 Model Year Verification: For the 2012 Hyundai Equus, you must physically inspect your original module and verify the part number is 921703M002. Hyundai used a different module on some vehicles produced that year, and only an exact part number match will work correctly.

Programming and Calibration: A Required Step

A replacement AFLS module is not a plug-and-play part. Whether you purchase a new or used module, it must be professionally programmed to your vehicle for it to function.

1. Parameter Downloading: A technician must use a Hyundai Global Diagnostic System (GDS) or equivalent high-level scan tool to perform 🎬 See how to use the Hyundai OEM scan tool. a "Parameter Download". This step tells the new module critical information about the vehicle's configuration.
2. Suspension Type: The most important parameter is the suspension type. The technician must select whether the vehicle has the electronic air suspension (found on the Equus) or the standard steel spring suspension. Loading the wrong parameter will cause the system to fail and set fault codes.
3. System Calibration: After the correct parameters are downloaded, vehicles without electronic air suspension may also require a system calibration to set the baseline level for the headlights.

Buying a Used AFLS Module

Given that a new OEM module can cost over $1,000, a used OEM module is a very popular and cost-effective repair option. Aftermarket versions of this specific module are not commonly available.

• Match the Part Number: This is the most important rule. The part number printed on the replacement module's sticker must be an exact match to your original.
• Inspect the Connectors: Check the pins in the electrical connectors for any signs of corrosion, moisture damage, or bent pins. Do not buy a module with damaged connectors.
• Source from a Reputable Recycler: Purchase from a seller that offers a warranty and guarantees the part is tested and functional.
• Factor in Programming Costs: Remember to include the cost of professional programming (typically $100-$200) when calculating your total repair cost.

Replacement Overview

The AFLS module is located inside the vehicle's cabin, under the dashboard on the driver's side. On the Hyundai Equus, it is found behind the crash pad lower panel, near the steering column. Replacement involves disconnecting the battery, removing the lower dash trim panels to gain access, unbolting the module, and disconnecting its electrical connectors. While the physical swap is straightforward for a DIY mechanic, the vehicle is not fixed until the programming is complete.

Cost Comparison

Frequently Asked Questions (FAQ)