ddiy — Family Car Docs

Document ID: 2107228

SIR component location affects how a vehicle should be serviced. There are parts of the SIR system installed in various locations around a vehicle. To find the location of the SIR components refer to Supplemental Inflatable Restraint System Description and Operation.

There are several reasons for disabling the SIR system, such as repairs to the SIR system or servicing a component near or attached to an SIR component. One example would be when adjusting the side door striker using a hammer or mallet. The ignition should be in the OFF position for ANY service work that requires impact to the body or frame. There are several ways to disable the SIR system depending on what type of service is being performed. The following information covers the proper procedures for disabling/enabling the SIR system.

Condition	Action
If the vehicle was involved in an accident with an air bag deployment.	Disconnect the negative battery cable(s) *. Refer to Repairs and Inspections Required After a Collision.
When performing SIR diagnostics.	Follow the appropriate SIR service manual diagnostic procedure(s) *
Disconnecting, removing or replacing an SIR component or a component attached to an SIR component. (Anytime you remove fasteners.)	Disconnect the negative battery cable(s) *
If the vehicle is suspected of having shorted electrical wires.	Disconnect the negative battery cable(s) *
When performing electrical diagnosis on components other than the SIR system.	Remove the SIR/Airbag fuse(s) when indicated by the diagnostic procedure to disable the SIR system
* DTC’s may be lost when the negative battery cable is disconnected.

SIR Service Precautions

Danger: Do not use a volt ohm meter or other device to check the electrical resistance of any SIR deployment component regardless if the connector is close to the inflator or far away from it. Test equipment can generate currents that may be large enough to ignite the squib used to initiate deployment which could lead to severe injuries or death. Even with a shorting clip in place, some test equipment could deliver more current than the shorting clip can safely shunt away.

Warning: Do not strike or jolt the inflatable restraint sensing and diagnostic module (SDM). Before applying power to the SDM, make sure that it is securely fastened with the arrow facing toward the front of the vehicle. Failure to observe the correct installation procedure could cause SIR deployment, personal injury, or unnecessary SIR system repairs.

Warning: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Failure to observe the correct procedure could cause deployment of the SIR components. Serious injury can occur. Failure to observe the correct procedure could also result in unnecessary SIR system repairs.

The Inflatable Restraint Sensing and Diagnostic Module (SDM) maintains a reserved energy supply. The reserved energy supply provides deployment power for the air bags if the Inflatable Restraint Sensing and Diagnostic Module loses battery power during a collision. Deployment power is available for as much as 2 minutes after disconnecting the vehicle power. Waiting 2 minutes before working on the system after disabling the SIR system prevents deployment of the air bags from the reserved energy supply.

The inflatable restraint sensing and diagnostic module (SDM) fasteners should not be removed until the battery is disconnected, and the SDM electrical connector is removed. Fasteners should be re-installed and torqued to proper specifications before reattaching the SDM electrical connector. The electrical connector must be reattached before reconnecting the negative battery cable to the battery.

The SDM is equipped with a roll-over sensor. Turning the SDM over while under power may result in airbag deployment. Make sure the SDM is completely disconnected for at least a minute before handling this module.

General Service Instructions

The following are general service instructions which must be followed in order to properly repair the vehicle and return it to its original integrity:

Do not expose air bags to temperatures above 85°C (185°F).
Verify the correct replacement part number. Do not substitute a component from a different vehicle.
Use only original GM replacement parts available from your authorized GM dealer. Do not use salvaged parts for repairs to the SIR system.

Discard any of the following components if it has been dropped from a height of 80 cm (31.5 Inches) or greater:

Inflatable Restraint Sensing and Diagnostic Module (SDM)
Any air bag
Driver steering wheel air bag coil
Any impact sensor
Seat belt anchor and/or retractor pretensioners
Passenger presence module and/or occupant sensor

Disabling Procedure – Air Bag Fuse

Turn the steering wheel so that the vehicles wheels are pointing straight ahead.
Place the ignition in the OFF position.

Warning: The SDM may have more than one fused power input. To ensure there is no unwanted SIR deployment, personal injury, or unnecessary SIR system repairs, remove all fuses supplying power to the SDM. With all SDM fuses removed and the ignition switch in the ON position, the AIR BAG warning indicator illuminates. This is normal operation, and does not indicate a SIR system malfunction.

Locate and remove the fuse(s) supplying power to the Inflatable Restraint Sensing and Diagnostic Module. Refer to SIR Schematics or Master Electrical Component List.
Wait 2 minutes before working on the system.

Enabling Procedure – Air Bag Fuse

Place the ignition in the OFF position.
Install the fuse(s) supplying power to the Inflatable Restraint Sensing and Diagnostic Module. Refer to SIR Schematics or Master Electrical Component List.
Turn the ignition switch to the ON position. The AIR BAG indicator will illuminate or flash then turn OFF.
Perform the Diagnostic System Check – Vehicle if the AIR BAG warning indicator does not operate as described. Refer to Diagnostic System Check - Vehicle.

Disabling Procedure – Negative Battery Cable

Turn the steering wheel so that the vehicles wheels are pointing straight ahead.
Place the ignition in the OFF position.
Disconnect the negative battery cable from the battery. Refer to Battery Negative Cable Disconnection and Connection.
Wait 2 minutes before working on system.

Enabling Procedure – Negative Battery Cable

Place the ignition in the OFF position.
Connect the negative battery cable to the battery. Refer to Battery Negative Cable Disconnection and Connection.
Turn the ignition switch to the ON position. The AIR BAG indicator will illuminate or flash then turn OFF.
Perform the Diagnostic System Check – Vehicle if the AIR BAG warning indicator does not operate as described. Refer to Diagnostic System Check - Vehicle.

Air Bag(s) Arming and Disarming