Airbag Module/Computer

This procedure covers the removal and replacement of the airbag control module (SDM - Sensing and Diagnostic Module) on the 2023 Chevrolet Bolt EUV, including proper deactivation and reactivation of the supplemental restraint system.

Warnings

Tools required

Parts

• Airbag Control Module (SDM) × 1 — GM Part 84632334 or equivalent

Preparation

1. Park vehicle on level ground and engage parking brake
2. Turn ignition to OFF position and remove key fob from vehicle interior
3. Ensure front seats are moved fully forward to access center console area
4. Open hood and locate 12V auxiliary battery (located in engine compartment)
5. If using a battery memory saver, connect it according to manufacturer instructions before battery disconnect
6. Disconnect 12V battery negative terminal and secure cable away from battery post
7. Wait a MINIMUM of 2 minutes with battery disconnected before proceeding (allow airbag system capacitors to discharge)
8. Verify ignition is OFF and will remain OFF during entire procedure
9. Document any existing DTCs using scan tool before beginning work

Procedure

1. 1

   Remove Center Console Lower Trim
   Working from inside the vehicle, locate and remove the center console lower trim panel. Remove the two front lower cover screws if present. Carefully pull the lower trim panel away from the console, releasing the retaining clips. Set trim panel aside in a safe location to avoid damage.
2. 2

   Access SDM Mounting Area
   With the lower trim removed, locate the airbag control module (SDM) mounted to a bracket in the center console tunnel area. The module is a rectangular metal box with multiple wire harness connectors. Position yourself comfortably to access the module - you may need to work from the driver's side footwell area looking toward the center of the vehicle.
3. 3

   Disconnect SDM Electrical Connectors
   Identify all electrical connectors attached to the SDM (typically 2-3 connectors with yellow connector housings indicating airbag system connections). Press the connector lock tabs and carefully disconnect each connector from the module. Pull connectors straight out - do not twist or bend. Note the orientation and position of each connector for reinstallation.
   ⚠Handle yellow airbag connectors with care. These connectors have special shorting bars that automatically short the circuits when disconnected. Do not attempt to probe or test these connectors while disconnected.
4. 4

   Remove Ground Strap Connection
   Locate the ground strap bolt connecting the SDM chassis ground to the vehicle body/bracket. Using an 8mm or 10mm socket (as applicable), remove the ground strap bolt. Keep the bolt and any washers in a safe place. Inspect the ground contact surfaces - they should be clean and free of corrosion.
   Torque spec

   Ground Strap Bolt14 Nm (10 lb-ft)
5. 5

   Remove SDM Mounting Bolts
   Locate the module mounting bolts securing the SDM to its bracket (typically 2-4 bolts). Using a 10mm socket, remove all mounting bolts while supporting the module with your other hand. Keep all bolts and washers organized for reinstallation.
   Torque spec

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

   Remove Airbag Control Module
   Carefully remove the SDM from its mounting bracket. Handle the module with care - avoid dropping, striking, or placing heavy objects on it. Inspect the mounting bracket for any damage or corrosion. Clean mounting surfaces if necessary. Store the old module in a safe location away from heat, moisture, and electromagnetic interference until proper disposal.
7. 7

   Inspect Mounting Hardware and Connectors
   Inspect all electrical connectors for signs of corrosion, damage, or bent pins. Inspect mounting bracket for cracks or damage. Check ground strap and contact surfaces - if corrosion is present, clean with a wire brush until bare metal is visible. Verify all mounting bolt holes are clean and threads are undamaged.
   ℹ️Clean ground contact surfaces are critical for proper airbag system operation. Ensure both the ground strap and mounting surface are free of paint, corrosion, and debris.
8. 8

   Install New SDM to Mounting Bracket
   Position the new airbag control module onto the mounting bracket, ensuring proper orientation (connector ports facing toward vehicle wiring). Start all mounting bolts by hand to ensure proper thread engagement. Once all bolts are started, torque them in a cross-pattern to specification using a torque wrench.
   ⚠️Ensure the module is firmly mounted before connecting any electrical connectors. A loose module can cause intermittent faults or deployment issues.
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
9. 9

   Install Ground Strap Connection
   Position the ground strap onto the mounting point, ensuring the contact surface is clean and making full metal-to-metal contact. Install the ground strap bolt with any washers in their original configuration. Torque the ground bolt to specification.
   ⚠A properly grounded SDM is critical for airbag system function. Verify clean contact and proper torque.
   Torque spec

   Ground Strap Bolt14 Nm (10 lb-ft)
10. 10

    Reconnect SDM Electrical Connectors
    Reconnect all electrical connectors to the new SDM in their original positions. Push each connector firmly until it clicks into place. Verify each connector is fully seated and the lock tab is engaged. Ensure wiring is routed properly and will not be pinched during trim reinstallation.
11. 11

    Reconnect 12V Battery
    Return to the 12V battery in the engine compartment. Remove battery memory saver if used. Clean battery terminal if necessary. Reconnect the negative battery cable to the negative battery post and torque the terminal bolt to specification.
    ⚠Do not overtighten battery terminal bolts. Maximum torque is 6.0 Nm (4.0 lb-ft) to prevent damage to battery post.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)
12. 12

    Program and Configure New SDM
    Connect GM MDI 2 or compatible scan tool to the vehicle's OBD-II diagnostic port. Turn ignition to ON position (do not start vehicle). Using GM SPS (Service Programming System), program the new airbag control module with the correct software and vehicle configuration. Follow all on-screen prompts. This process typically takes 10-30 minutes and must not be interrupted.
    ⚠️Programming is MANDATORY and must be completed before the vehicle can be safely operated. An unprogrammed or incorrectly programmed SDM will not deploy airbags properly during a collision.
    ⚠Ensure vehicle battery is fully charged and maintain stable power during programming. A programming interruption may require module replacement.
13. 13

    Clear DTCs and Verify System Operation
    After programming is complete, use the scan tool to clear all airbag system DTCs. Turn ignition OFF, then back to ON. Observe the airbag warning light on the instrument cluster - it should illuminate for approximately 6 seconds during bulb check, then extinguish. Perform a complete system scan to verify no DTCs are present. If any DTCs remain, diagnose and correct before proceeding.
    ⚠️Do NOT return the vehicle to service if the airbag warning light remains illuminated or if any airbag DTCs are present. This indicates a system malfunction that must be corrected.
14. 14

    Reinstall Center Console Trim
    Verify all wiring is properly routed and will not be pinched. Reinstall the center console lower trim panel, ensuring all retaining clips are properly engaged. Install and tighten any trim panel screws. Verify trim panel is secure and properly aligned.

Reassembly

1. Ensure all electrical connectors are fully seated with lock tabs engaged
2. Verify all mounting bolts are torqued to specification
3. Confirm ground strap connection is clean and properly torqued
4. Ensure center console trim is properly reinstalled and secure
5. Return front seats to normal operating positions

Verification

• Turn ignition to ON position and verify airbag warning light performs bulb check (illuminates for ~6 seconds then turns OFF)
• Perform complete vehicle scan with diagnostic scan tool - verify NO airbag system DTCs are present
• Verify airbag warning light remains OFF during normal operation
• Test drive vehicle and verify no airbag warning light illumination during driving
• Perform final scan after test drive to confirm no new DTCs have set
• Document module replacement, programming date/time, and verification results in vehicle service records
• If airbag light remains illuminated or any DTCs are present, DO NOT return vehicle to customer - diagnose and repair fault immediately

More procedures for this vehicle