Hummer H2. Manual — part 2033

The inflatable restraint sensing and diagnostic module (SDM) maintains a reserved energy supply. The reserved
energy supply provides deployment power for the air bags. Deployment power is available for as much as 1
minute after disconnecting the vehicle power. Disabling the SIR system prevents deployment of the air bags
from the reserved energy supply.

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:

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Do not expose inflator modules to temperatures above 65°C (150°F).

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Verify the correct replacement part number. Do not substitute a component from a different vehicle.

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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 91 cm (3 ft) or greater:

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Inflatable restraint electronic frontal sensor (EFS)

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Inflatable restraint I/P module

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Inflatable restraint sensing and diagnostic module (SDM)

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Inflatable restraint steering wheel module

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Inflatable restraint steering wheel module coil

SIR DISABLING AND ENABLING ZONE 1

Disabling Procedure

1. Turn the steering wheel so that the vehicle's wheels are pointing straight ahead.

2. Turn OFF the ignition.

3. Remove the key from the ignition.

4. Remove the engine protection shield, if equipped.

CAUTION: When performing service on or near the SIR components or the SIR

wiring, the SIR system must be disabled. Refer to SIR Disabling and
Enabling Zones. Failure to observe the correct procedure could cause
deployment of the SIR components, personal injury, or unnecessary SIR
system repairs.

IMPORTANT: Refer to SIR Service Precautions before disabling the SIR system.

IMPORTANT: With the SIR fuse removed and the ignition ON, the AIR BAG indicator

illuminates. This is normal operation and does not indicate an SIR system
malfunction.

2004 Hummer H2

2004 RESTRAINTS SIR - Hummer H2

Fig. 6: SIR Fuse & Underhood Fuse Block
Courtesy of GENERAL MOTORS CORP.

5. Remove the SIR fuse (1) from the underhood fuse block.

6. Raise and support the vehicle.

2004 Hummer H2

2004 RESTRAINTS SIR - Hummer H2

Fig. 7: CPA & EFS Connectors Located On The Frame Crossmember
Courtesy of GENERAL MOTORS CORP.

7. Remove the connector position assurance (CPA) from both electronic frontal sensor (EFS) connectors

located on the frame crossmember.

8. Disconnect the EFS connectors.

Enabling Procedure

2004 Hummer H2

2004 RESTRAINTS SIR - Hummer H2

Fig. 8: CPA & EFS Connectors Located On The Frame Crossmember
Courtesy of GENERAL MOTORS CORP.

1. Connect the EFS connectors to the EFS.

2. Install the CPA to the EFS connectors.

2004 Hummer H2

2004 RESTRAINTS SIR - Hummer H2