Chevrolet Silverado / GMC Sierra. Service manual - part 671

6. If all circuits test normal, replace the inflatable restraint passenger air bag on/off indicator.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for IPC and SDM replacement, setup, and programming

Inflatable Restraint Instrument Panel Module Indicator Replacement

SIR DISABLING AND ENABLING

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 SIR Identification Views.

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. 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.

SIR Service Precautions

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) *

When removing or replacing an SIR
component or a component attached to an
SIR component.

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

* DTCs will be lost when the negative battery cable is disconnected.

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

the SIR wiring, the SIR system must be disabled. Failure to

2008 Chevrolet Silverado 1500

2008 RESTRAINTS Supplemental Inflatable Restraints - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

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 SDM loses battery
power during a collision. Deployment power is available for as much as 1 minute after
disconnecting the vehicle power. Waiting 1 minute before working on the system after 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:

Do not expose inflator modules to temperatures above 65°C (150°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 91 cm (3 feet) or
greater:

Inflatable restraint sensing and diagnostic module (SDM)

Any Inflatable restraint air bag module

Inflatable restraint steering wheel module coil

Any Inflatable restraint sensor

Inflatable restraint seat belt pretensioners

Inflatable restraint Passenger Presence System (PPS) module or sensor

Disabling Procedure - Air Bag Fuse

1. Turn the steering wheel so that the vehicles wheels are pointing straight ahead.

2. Place the ignition in the OFF position.

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.

IMPORTANT: The SDM may have more than one fused power input. To

ensure there is no unwanted SIR deployment, personal injury,

2008 Chevrolet Silverado 1500

2008 RESTRAINTS Supplemental Inflatable Restraints - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

3. Locate and remove the fuse(s) supplying power to the SDM. Refer to SIR Schematics or

Electrical Center Identification Views .

4. Wait 1 minute before working on the system.

Enabling Procedure - Air Bag Fuse

1. Place the ignition in the OFF position.

2. Install the fuse(s) supplying power to the SDM. Refer to SIR Schematics or Electrical

Center Identification Views .

3. Turn the ignition switch to the ON position. The AIR BAG indicator will flash then turn

OFF.

4. 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

1. Turn the steering wheel so that the vehicles wheels are pointing straight ahead.

2. Place the ignition in the OFF position.

3. Disconnect the negative battery cable from the battery. Refer to Battery Negative Cable

Disconnection and Connection (w/Single Battery) or Battery Negative Cable
Disconnection and Connection (w/Auxiliary Battery) or Battery Negative Cable
Disconnection and Connection (w/Dual Batteries) .

4. Wait 1 minute before working on system.

Enabling Procedure - Negative Battery Cable

1. Place the ignition in the OFF position.

2. Connect the negative battery cable to the battery. Refer to Battery Negative Cable

3. Turn the ignition switch to the ON position. The AIR BAG indicator will flash then turn

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.

2008 Chevrolet Silverado 1500

2008 RESTRAINTS Supplemental Inflatable Restraints - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

OFF.

4. Perform the Diagnostic System Check - Vehicle if the AIR BAG warning indicator does not

operate as described. Refer to Diagnostic System Check - Vehicle .

REPAIR INSTRUCTIONS

SIR SERVICE PRECAUTIONS

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:

Do not expose inflator modules to temperatures above 65°C (150°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 91 cm (3 ft) or
greater:

Inflatable restraint sensing and diagnostic module (SDM)

Inflatable restraint I/P module

Inflatable restraint steering wheel module

Inflatable restraint steering wheel module coil

Inflatable restraint roof side rail modules

Inflatable restraint side impact sensors (SIS)

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. Failure to observe the correct
procedure could cause deployment of the SIR components,
personal injury, or unnecessary SIR system repairs.

2008 Chevrolet Silverado 1500

2008 RESTRAINTS Supplemental Inflatable Restraints - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra &

Silverado

Content .. 669 670 671 672 ..