SERVICE MANUAL UPDATE SEC. 8C4 SIR DISABLING/ENABLING PROC.

SUBJECT: SERVICE MANUAL UPDATE - INSTRUMENT PANEL GAUGES AND CONSOLE SECTION 8C-4 "(SIR) DISABLING-ENABLING PROCEDURE

VEHICLES AFFECTED: 1991 'C' MODEL

Service Precautions as well as Disabling and Enabling Procedures for the Supplemental Inflatable Restraint (SIR) System were not included in Instrument Panel, Gages and Console Section 8C. The following information should appear on 8C-4 immediately following On-Vehicle Service.

ON-VEHICLE SERVICE

SERVICE PRECAUTIONS

The DERM can maintain sufficient voltage to cause a deployment for 10 minutes after the ignition switch is turned off and the battery is disconnected. Many of the service procedures require disconnection of the SIR fuse and inflator module from the deployment loop to avoid an accidental deployment. Diagnostic procedures do not normally require fuse removal or disconnection of the inflator module. Always refer to GM service procedures for diagnosis.

CAUTION:

When performing service on or around SIR components or SIR wiring, follow the procedures listed below to temporarily disable the SIR system. Refer to appropriate service manual procedures. Failure to follow procedures could result in possible air bag deployment, personal injury, or unneeded SIR system repairs.

DISABLING THE SUPPLEMENTAL INFLATABLE RESTRAINT (SIR) SYSTEM

[( )] Remove or Disconnect

o Turn ignition switch to "OFF."

1. SIR fuse #7 from fuse panel.

2. Left sound insulator, refer to INSTRUMENT PANEL, GAGES AND CONSOLE (SECTION 8C).

3. Connector position assurance (CPA) and yellow two-way SIR harness connector at base of steering column.

ENABLING THE SUPPLEMENTAL INFLATABLE RESTRAINT (SIR) SYSTEM

[) (] Install or Connect

1. Yellow two-way SIR harness connector at base of steering column, and connector position assurance (CPA).

2. Left sound insulator, refer to INSTRUMENT PANEL, GAGES AND CONSOLE (SECTION 8C).

3. SIR fuse #7 into fuse panel.

Turn the ignition switch to "RUN" and verify the "INFLATABLE RESTRAINT" indicator lamp flashes 7 to 9 times and then goes out. If the lamp does not operate as indicated, refer to SUPPLEMENTAL INFLATABLE RESTRAINT (SIR) SYSTEM DIAGNOSIS (SECTION 9J-A).

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.