Airbag Module/Computer

Remove and replace the airbag control module (ACM) located under the center console, including proper system deactivation, module disconnection, and post-installation verification with diagnostic scanning.

Warnings

Tools required

Parts

• Airbag control module (ACM) × 1 — Use OEM specification - Aston Martin part number specific to 2009 DB9
• Module mounting bolts (if corroded) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake.
2. Turn ignition to OFF position and remove key fob from vehicle interior.
3. Open driver's door and leave open throughout procedure (prevents accidental locking).
4. If equipped with battery memory saver, install per manufacturer instructions before disconnecting battery.
5. Connect diagnostic scanner and document all airbag system fault codes and freeze frame data.
6. Disconnect negative battery terminal first, then positive terminal.
7. Wait minimum 10 minutes for airbag system capacitors to fully discharge before proceeding.
8. Photograph center console area and trim panel orientation for reinstallation reference.

Procedure

1. 1

   Remove Gear Selector Surround Trim
   Starting at the rear of the gear selector surround, use plastic trim tools to carefully release the trim panel clips. The panel surrounds the gear selector and extends rearward toward the center console armrest. Lift the panel upward once all clips are released. Disconnect any electrical connectors for switches or lighting if present on this trim piece.
2. 2

   Remove Center Console Lower Trim Panels
   Identify and remove the lower side trim panels on both driver and passenger sides of the center console tunnel. These panels are typically secured with plastic clips and may have Torx fasteners at the front edges. Work carefully to avoid breaking clips on these leather-wrapped or trimmed panels. Set panels aside in a protected area.
3. 3

   Access Console Mounting Fasteners
   With lower trim removed, locate the center console mounting fasteners. These are typically Torx bolts (T25 or T30) located at the front near the dashboard interface and at the rear near the seats. Remove all visible console mounting fasteners, noting their locations and lengths for reinstallation.
4. 4

   Disconnect Console Electrical Connections
   Before lifting console, identify and disconnect all electrical connectors routed to console-mounted components. This typically includes: cigarette lighter/power outlet, window switches, climate control interfaces, and any audio system controls. Use care with connector locking tabs - most are push-tab or slide-lock types.
5. 5

   Remove Center Console Assembly
   With all fasteners and connectors released, carefully lift the center console assembly upward and rearward. The console may require slight manipulation to clear the gear selector and handbrake lever. Work slowly to avoid snagging wiring harnesses. Set console in a safe location where it will not be damaged.
6. 6

   Locate Airbag Control Module
   With console removed, locate the airbag control module. Its exact mounting location MUST be verified against 2009 DB9 factory service information before proceeding, as the module may be located on the transmission tunnel/floor pan beneath the center console area and not simply 'between the seats.' The module is a metal box with a large multi-pin airbag connector and a bracket secured with bolts; confirm its physical description and connector color against factory documentation rather than assuming. yellow or orange for airbag system identification) and a mounting bracket secured with bolts. Note: With console removed, locate the airbag control module. On the 2009 DB9 verify the exact mounting location against factory service information (commonly on the floor pan beneath the center console/tunnel area), as the module position must be confirmed before proceeding. Note: With console removed, locate the airbag control module. Verify its exact mounting location against 2009 DB9 factory service documentation — on this platform the ACM is typically mounted to the transmission tunnel beneath the center console area rather than rearward between the seats.
7. 7

   Document Module Connector Orientation
   Before disconnecting, photograph the module connector orientation and any connector locking mechanism. Note the position of the connector lock tab (typically a red or yellow sliding lock). Verify that the manufacturer-specified capacitor discharge time has fully elapsed since battery disconnection (commonly 10+ minutes, but confirm the exact standby time against 2009 DB9 factory documentation).
8. 8

   Disconnect Airbag Module Connector
   Release the connector locking mechanism by sliding or pressing the lock tab as designed. Grasp the connector body (NOT the wires) and pull straight away from the module. Do not wiggle or twist excessively. Inspect connector pins for damage, corrosion, or bent contacts. If connector shows damage, replacement may be required.
9. 9

   Remove Module Mounting Fasteners
   Remove the module mounting bolts securing the bracket to the floor pan/transmission tunnel. The exact bolt count (likely two to four) MUST be confirmed against 2009 DB9 factory service information before removal. Keep track of any washers or grounding straps that may be installed under bolt heads. Note: Remove the module mounting bolts securing the bracket to the floor pan. Confirm the exact bolt count and torque against 2009 DB9 factory service information before removal, keeping track of any washers or grounding straps that may be installed under bolt heads. Note: Remove the module mounting bolts securing the bracket to the transmission tunnel, noting the exact count and location per 2009 DB9 factory documentation. These bolts are accessible from above.
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
10. 10

    Remove Old Airbag Control Module
    Lift the module and mounting bracket assembly away from the transmission tunnel. Handle with care - do not drop or strike the module. Place the old module in an anti-static bag if available. Note: Most modules have an arrow indicating proper installation orientation.
11. 11

    Inspect Mounting Area and Wiring
    Inspect the transmission tunnel mounting surface for damage, corrosion, or debris. Clean mounting surface if necessary. Inspect the vehicle-side wiring harness and connector for damage, corrosion, frayed wires, or pushed-back pins. Any wiring damage must be repaired before installing new module.
12. 12

    Install New Airbag Control Module
    Remove new module from packaging, handling by the bracket only. Position the new module in the mounting location, ensuring correct orientation (match arrow marking on module to vehicle orientation if present). Ensure no wiring harnesses are pinched beneath the module bracket. Install mounting bolts with any washers or grounding straps, tightening in a cross pattern to the factory-specified torque for the 2009 DB9 ACM bracket bolts. Do not assume a value — these are typically small (M6-class) fasteners requiring low torque; confirm the exact figure against Aston Martin documentation before tightening. Note: Install mounting bolts with any washers or grounding straps, tightening in a cross pattern to the torque specified in 2009 DB9 factory documentation for the ACM mounting bolts.
    Torque spec

    Module Mounting Bolts8 Nm (6 lb-ft)
13. 13

    Connect Module Electrical Connector
    Align the large multi-pin connector with the module receptacle, ensuring correct orientation. Push connector straight into module until it seats fully with an audible click. Engage the connector locking mechanism (slide lock tab to locked position). Verify connector is fully locked by attempting gentle pull-back - connector should not separate.
14. 14

    Reinstall Center Console Assembly
    Position center console assembly back into vehicle, carefully guiding it over the gear selector and handbrake lever. Reconnect all electrical connectors that were disconnected during removal, ensuring each connector locks securely. Install console mounting fasteners in their original locations, tightening in a pattern from front to rear.
15. 15

    Reinstall Console Trim Panels
    Reinstall lower side trim panels on both sides of the center console, ensuring all clips engage properly and any Torx fasteners are installed. Reinstall the gear selector surround trim, pressing firmly to engage all clips. Reconnect any electrical connectors for switches or lighting in trim panels.
16. 16

    Reconnect Battery and Initialize System
    Reconnect positive battery terminal first, then negative terminal (note: the 2009 DB9 battery is located in the trunk), torquing the terminal clamp bolts to the factory-specified value which MUST be verified against 2009 DB9 documentation. Ensure key fob is outside vehicle. Turn ignition to ON position (do not start engine). The airbag warning light should perform its bulb-check cycle, illuminating briefly on key-on and then extinguishing. The exact self-check duration MUST be verified against 2009 DB9 factory information rather than assuming a generic value. If light remains on, flashes abnormally, or does not illuminate at all, do not drive vehicle - proceed immediately to diagnostic verification. Note: Reconnect positive battery terminal first, then negative terminal, torquing to the manufacturer-specified value (verify against 2009 DB9 factory data). Note the DB9 battery is located in the trunk. Note: The airbag warning light should perform its bulb-check/self-test sequence (duration per 2009 DB9 specification) and then extinguish. Note: Reconnect positive battery terminal first, then negative terminal, torquing to the battery terminal clamp specification in 2009 DB9 factory documentation.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)
17. 17

    Program and Configure New Module
    Connect factory-level diagnostic equipment (Aston Martin diagnostic system or approved equivalent). Access airbag control module programming menu. Program the new module with vehicle VIN, configuration data, and calibration files as required by manufacturer procedure. This step is critical - an unprogrammed module may not function correctly.
18. 18

    Clear Fault Codes and Verify System
    Use diagnostic scanner to clear any installation-related fault codes. Perform airbag system self-test through scanner menu. Verify all airbag components (driver airbag, passenger airbag, side airbags, curtain airbags, seat belt pretensioners, and all crash sensors) are communicating properly. All components should show 'ready' or 'active' status with no fault codes present.

Reassembly

1. Reassembly follows removal in reverse order, with particular attention to electrical connector locking and console trim clip engagement.
2. Verify all trim panels are flush and properly seated with no gaps or misalignment.
3. Ensure no warning lights remain illuminated on instrument cluster after battery reconnection.

Verification

• Turn ignition to ON position: Airbag warning light should illuminate for approximately 6 seconds then extinguish completely.
• Perform diagnostic scan: Zero airbag system fault codes should be present; all airbag components should report 'ready' status.
• Verify airbag warning light does not illuminate during a 5-minute test drive with various steering inputs and vehicle movements.
• Check that all center console functions (power outlets, switches, climate controls) operate normally after reassembly.
• Confirm all trim panels are secure with no rattles or loose components.
• CRITICAL: If airbag warning light remains on, flashes, or any fault codes are present after programming, the system is NOT safe. Do not drive vehicle until issue is resolved.
• Consider professional verification scan at qualified facility to confirm proper system operation before returning vehicle to service.

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle