Home ReviewsRefund
Home/Cadillac/DeVille Concours/Cadillac DeVille Concours I final (1999-1999)/Repair manual/Airbag/Supplemental Inflatable Restraint System
Contents Section: Airbag All sections

Supplemental Inflatable Restraint System Cadillac DeVille Concours I final

Airbag 22 illustrations ~18761 words

CONNECTOR IDENTIFICATION

Note. Refer to illustrations to identify SIR connector terminals. (Scheme 1)-21.

Scheme 1

Scheme 1: CONNECTOR IDENTIFICATION
Scheme 1: CONNECTOR IDENTIFICATION

Scheme 2

Scheme 2
Scheme 2

Scheme 3

Scheme 3
Scheme 3

Scheme 4

Scheme 4
Scheme 4

Scheme 5

Scheme 5
Scheme 5

Scheme 6

Scheme 6
Scheme 6

DESCRIPTION & OPERATION

WARNINGTo avoid injury from accidental air bag deployment, read and carefully follow all WARNINGS and SERVICE PRECAUTIONS .

Note. Side impact air bag modules may also be referred to as driver/passenger's door air bag modules.

SUPPLEMENTAL INFLATABLE RESTRAINT (SIR) SYSTEM

Supplemental Inflatable Restraint (SIR) system is designed to supplement protection provided by driver and passenger-side seat belts. A frontal crash of sufficient force up to 30 degrees off center line of vehicle will deploy driver and passenger-side air bags. Steering column and knee bolsters below instrument panel also absorb crash energy.

Side Impact Air Bag System supplements protection offered by driver-side and front passenger-side doors, and vehicle structure. Upon a side crash of sufficient force, side impact air bag system deploys an air bag from driver-side or front passenger-side door panel.

SIR system consists of Sensing and Diagnostic Module (SDM), Side Impact Sensing Modules (SISM), front-end discriminating sensor, driver and passenger-side air bag modules, side impact air bag modules, SIR coil assembly and AIR BAG warning light in instrument cluster.

SENSING AND DIAGNOSTIC MODULE (SDM)

SDM monitors vehicle velocity changes to detect frontal crashes which are severe enough to warrant air bag module deployment. When a frontal crash of sufficient force is detected, SDM causes enough current to flow through air bag modules to deploy air bags. SDM also maintains a 23 Volt Loop Reserve (23 VLR) energy supply to provide deployment energy for up to 10 minutes after loss of ignition voltage.

Additionally, SDM provides diagnostic monitoring of SIR system electrical components. When a malfunction is detected, SDM sets a Diagnostic Trouble Code (DTC) which can be retrieved using a scan tool. SDM warns driver of system malfunctions by controlling AIR BAG warning light.

SIDE IMPACT SENSING MODULE (SISM)

The Side Impact Sensing Modules (SISM) monitors door velocity changes to detect side crashes which are severe enough to warrant air bag module deployment. When a side crash of sufficient force is detected, SISM on impact side causes enough current flow through air bag modules to deploy respective air bag module. The SISM also maintains a 23 Volt Loop Reserve (23 VLR) energy supply to provide deployment energy in cases where ignition voltage is lost in a frontal crash.

Additionally, SISM provides diagnostic monitoring of side impact SIR system electrical components. When a malfunction is detected, SISMs communicate status of side impact system to SDM, which sets a diagnostic trouble code (DTC) that is retrieved using a scan tool. SDM warns driver of system malfunctions by controlling AIR BAG warning light.

AIR BAG WARNING LIGHT

AIR BAG warning light is installed in Instrument Panel Cluster (IPC). SDM communicates with IPC using serial data communications. When ignition switch is first turned ON, AIR BAG warning light verifies system operation by flashing 7 times and turning off. During vehicle operation, AIR BAG warning light warns driver of malfunctions which could potentially affect SIR system operation.

FRONT-END DISCRIMINATING SENSOR

Front-end discriminating sensor is an auxiliary sensor which assists SDM in determining when deployment should occur by providing an input signal. Although front-end discriminating sensor is a mechanical sensor, it is not part of deployment loop.

SIR COIL ASSEMBLY

SIR coil assembly consists of 2 or more current-carrying coils. Coils are attached to steering column and allow rotation of steering wheel, while maintaining continuous (directly wired) contact of deployment loop through driver-side air bag module.

Shorting bar on Yellow 2-pin connector shorts circuits to SIR coil and driver-side air bag module when disconnected. This prevents deployment of air bag module when servicing steering column or other SIR components.

AIR BAG MODULES

Air bag modules consist of an inflatable bag and an inflator. When vehicle is in an accident of sufficient force, SDM causes current flow through deployment loops. Current passing through modules ignites inflator charges, producing gas which rapidly inflates air bags.

Shorting bars on Yellow 2-pin connectors short circuits to driver-side, passenger-side and side impact air bag modules when disconnected. This prevents deployment of air bag modules when servicing SIR components.

KNEE BOLSTERS

Knee bolsters are used to absorb energy and control forward movement of front passengers. This is accomplished by limiting leg movement during a frontal crash.

SERVICE PRECAUTIONS

Observe the following precautions when working with SIR system

  1. SDM maintains sufficient voltage to cause air bag deployment for up to 10 minutes after ignition switch is turned OFF, battery is disconnected, or fuse powering SDM is removed. In order to begin servicing immediately, air bag modules must be removed from deployment loop. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system) .
  2. After repairs, ensure AIR BAG warning light is working properly and no system faults are indicated. See «SYSTEM OPERATION CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__system-operation-check) .
  3. Always wear safety glasses when servicing or handling an air bag module.
  4. Air bag modules must be stored in original special containers until used for service. Store in a clean, dry place, away from sources of extreme heat, sparks, or high electrical energy.
  5. Air bag modules or SDMs should not be subjected to temperatures greater than 150°F (65°C).
  6. Air bag modules or SDMs should not be used if they have been dropped from a height of 3 feet or greater.
  7. When placing a live air bag module on a bench or other surface, always make certain that trim cover faces up. This will reduce motion of module if accidentally deployed.
  8. After deployment, air bag surface may contain deposits of sodium hydroxide, which can irritate skin. Always wear safety glasses, rubber gloves and long-sleeved shirt during clean-up, and wash hands using mild soap and water. Follow correct disposal procedures. See «DISPOSAL PROCEDURES»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disposal-procedures) .
  9. At no time should any electrical source be allowed near inflator on back of air bag module.
  10. DO NOT apply power to SIR system unless all components are connected or a diagnostic chart requests it, as this will set a diagnostic trouble code.
  11. When carrying a live air bag module, trim cover should be pointed away from body to minimize injury in case of accidental deployment.
  12. DO NOT attempt to service any SIR component. All defective SIR components must be replaced.
  13. DO NOT probe a wire through insulator; this damages wire and eventually causes failure due to corrosion.
  14. When performing electrical tests, prevent accidental shorting of terminals. Such mistakes can damage fuses or components and may cause a second fault code to set, making diagnosis of original problem more difficult.
  15. When using diagnostic charts to diagnose SIR system, under no circumstances should a volt/ohmmeter, test light or any type of electrical equipment not specified by manufacturer be used. See «SPECIAL TOOLS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__special-tools) .
  16. If SIR system is not fully functional for any reason, vehicle should not be driven until system is repaired. DO NOT remove bulbs, modules, sensors or other components or in any way disable system from operating normally.

SPECIAL TOOLS

To avoid accidental deployment when working on SIR system, use only electrical test equipment specified by manufacturer. See SIR RECOMMENDED TOOLS table.

Tool NameTool Number
Connector Test Adapter KitJ-35616-A
Digital MultimeterJ-39200
Scan ToolTech 2
SIR Deployment HarnessJ-38826
SIR Driver/Passenger Load ToolJ-38715-A
Steering Column Lock PinJ-42640
Steering Wheel PullerJ-1859-A
Steering Wheel Puller LegsJ-42578
Terminal Repair KitJ-38125-B

SIR RECOMMENDED TOOLS

CENTERING COIL ASSEMBLY

  1. If coil assembly has been removed from steering column and is being reinstalled, go to next step. New coil assemblies are pre-centered and include a centering tab that is removed once coil is installed.
  2. Hold coil assembly with clear bottom upward to see coil bottom. While holding coil assembly housing, depress spring lock and rotate hub in direction of arrow until it stops. Coil ribbon should now be wound up snugly against center hub. Rotate coil hub in opposite direction approximately 2 1/2 turns. Release spring lock between locking tabs. (Scheme 7)

Scheme 7

Scheme 7
Scheme 7

DISABLING & ACTIVATING AIR BAG SYSTEM

CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES in GENERAL INFORMATION. Record preset radio stations and obtain code for theft deterrent-equipped radios before disconnecting battery.

DISABLING SYSTEM

WARNINGSDM maintains sufficient voltage to cause air bag deployment for up to 10 minutes after ignition switch is turned OFF, battery is disconnected, or fuse powering SDM is removed. In order to begin servicing immediately, air bag modules must be removed from deployment loop.

Note. When SIR fuse is removed and ignition switch is in RUN position, AIR BAG warning light will be on. This does not indicate a system malfunction.

Frontal Air Bag System

  1. Turn steering wheel to place vehicle wheels in straight-ahead position. Turn ignition switch OFF and remove key.
  2. Remove SIR fuse (20-amp) from trunk fuse block, located behind carpet in left front corner of trunk. Remove left sound insulator panel. Remove Connector Position Assurance (CPA) clip and disconnect driver-side Yellow 2-pin connector near base of steering column. (Scheme 8)
  3. Remove glove box. Remove CPA clip and disconnect passenger-side Yellow 2-pin connector. (Scheme 9)

Scheme 8

Scheme 8
Scheme 8

Scheme 9

Scheme 9
Scheme 9

Side Air Bag System

  1. Remove key from ignition switch. Remove SIR fuse (20-amp) from trunk fuse block, located behind carpet in left front corner of trunk.
  2. Remove door trim panel. Remove Connector Position Assurance (CPA) clip and disconnect side impact air bag module Yellow 2-pin connector located near SISM in door. (Scheme 10) Repeat for other side air bag.

Scheme 10

Scheme 10
Scheme 10
  1. Remove key from ignition switch. Connect passenger-side air bag Yellow 2-pin connector and install CPA clip. (Scheme 9) Attach passenger-side air bag Yellow 2-pin connector to instrument panel metal structure and ensure wiring harness is routed away from HVAC mix door actuator. Install glove box.
  2. Connect driver-side Yellow 2-pin connector near base of steering column and install CPA clip. (Scheme 8) Install left sound insulator panel and SIR fuse. Stay away from air bags and turn ignition switch to RUN position. Check AIR BAG warning light for proper system function. See «SYSTEM OPERATION CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__system-operation-check).
  1. Remove key from ignition switch. Connect side impact air bag Yellow 2-pin connector located near SISM in door and install CPA clip. (Scheme 10) Install door trim panel.
  2. Repeat for other side air bag. Install SIR fuse to trunk fuse block, located behind carpet in left front corner of trunk. Check system for proper operation. See «SYSTEM OPERATION CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__system-operation-check).

DISPOSAL PROCEDURES

WARNINGTo prevent accidental deployment and personal injury, deploy air bags before disposal. DO NOT dispose of undeployed air bag modules at normal refuse locations. Undeployed air bag modules contain substances that can cause severe illness or personal injury if sealed container is damaged during disposal.

Note. If vehicle is to be scrapped, perform on-vehicle air bag deployment procedure.

ON-VEHICLE DEPLOYMENT

  1. Before proceeding, see «SERVICE PRECAUTIONS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__service-precautions). Turn ignition switch OFF, remove key and put on safety glasses. Disconnect driver-side and passenger-side air bag module Yellow 2-pin connectors. (Scheme 8)and (Scheme 9). Disconnect driver's and passenger's door air bag module Yellow 2-pin connectors. (Scheme 10)
  2. Cut air bag module harness connector from vehicle leaving at least 6" of wire at the connector. Strip 1/2" (13 mm) of insulation from each wire lead to the connector. Cut 2 deployment wires at least 20 feet long from 18-gauge multi-strand wire. Strip 1/2" (13 mm) of insulation from each connector wire lead. Cut 2 15-foot deployment wires from 18-gauge multi-strand wire. Strip 1/2" (13 mm) of insulation from both ends of wires. Twist wires together at one end to short.
  3. Twist together one connector wire lead to other end of each deployment wire. (Scheme 11) Bend twisted connection flat and wrap tightly with electrical tape to insulate. Repeat this step for other connector wire lead.
  4. Remove all loose objects from front seat, and ensure no one is in vehicle. Connect deployment harness to air bag module connector. Stretch wires away from car as far as possible.
  5. Repeat steps 2-4 for passenger-side and side impact air bag modules. (Scheme 12)and (Scheme 13). Cover windshield and front door openings with a drop cloth.
  6. Separate wire ends. Connect wires to a 12-volt battery. Air bag should deploy. Disconnect wires from battery. DO NOT touch metal surfaces of air bag module for at least 10 minutes due to heat generated during deployment. Wear gloves and safety glasses when handling deployed air bag module. Wash hands with mild soap and water. Dispose of deployed air bag module like any other part. Repeat deployment procedure for passenger-side air bag.
  7. If air bag modules do not deploy, carefully remove from vehicle. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Temporarily store module with trim facing up. Contact manufacturer for proper disposal instructions.

Scheme 11

Scheme 11
Scheme 11

Scheme 12

Scheme 12
Scheme 12

Scheme 13

Scheme 13
Scheme 13

OFF-VEHICLE DEPLOYMENT

  1. Before proceeding, see «SERVICE PRECAUTIONS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__service-precautions). Turn ignition switch OFF, remove key and put on safety glasses. Short 2 SIR Deployment Harness (J-38826) leads together by fully seating one banana plug into the other. Connect appropriate pigtail adapter to SIR deployment harness. (Scheme 14)
  2. Remove driver-side air bag module. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation).
  3. Place air bag module on ground (preferably outdoors) at least 6 feet away from any people or objects. Stretch SIR deployment harness and pigtail adapter from air bag module to its full length. Place a 12-volt battery near shorted end of SIR deployment harness.
  4. Connect air bag module to pigtail adapter on SIR deployment harness. (Scheme 14) Ensure area around air bag module is clear of people and objects. Verify that air bag module is resting with trim cover facing up.
  5. Separate 2 banana plugs on SIR deployment harness. Connect SIR deployment harness wires to battery. (Scheme 14) Air bag module should deploy immediately. If air bag module does not deploy, go to next step. Disconnect SIR deployment harness from battery. Short 2 SIR deployment harness leads together. DO NOT touch metal surfaces of air bag module for at least 10 minutes due to heat generated during deployment. Wear gloves and safety glasses when handling deployed air bag module. Wash hands with mild soap and water after handling. Dispose of deployed air bag module like any other part. Inspect pigtail adapter and SIR deployment harness for damage after each use. Repeat deployment procedure for passenger-side and side impact air bag modules.
  6. Ensure that SIR deployment harness is disconnected from battery and that 2 banana plugs have been shorted together. Disconnect pigtail adapter from air bag module. Temporarily store air bag module with trim cover facing up. Contact manufacturer for proper disposal instructions.

Scheme 14

Scheme 14
Scheme 14

POST-COLLISION INSPECTION

When a vehicle has been involved in a collision, certain components of the passive restraint system must be inspected or replaced. See PASSIVE RESTRAINT SYSTEM INSPECTION article in the GENERAL INFORMATION section for post-collision inspection information.

REMOVAL & INSTALLATION

WARNINGFailure to follow service precautions may result in air bag deployment and personal injury. See SERVICE PRECAUTIONS . After component replacement, check system operation. See SYSTEM OPERATION CHECK .

Removal

  1. Before proceeding, see «SERVICE PRECAUTIONS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system).
  2. Remove driver seat and sill plate. Fold back carpet and insulation to access SDM. Remove Connector Position Assurance (CPA) clip and disconnect SDM harness connector. (Scheme 15) Remove SDM fasteners and SDM.

Installation

  1. Mount SDM on vehicle, ensuring arrow points toward front of vehicle. Install SDM fasteners and tighten to 80 INCH lbs. (9 N.m). Reconnect SDM harness connector and CPA clip.
  2. Position carpet and insulation over SDM. Install driver seat and sill plate. Activate air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system) . Check system for proper operation. See «SYSTEM OPERATION CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__system-operation-check) .

Scheme 15

Scheme 15
Scheme 15
  1. Before proceeding, see «SERVICE PRECAUTIONS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system).
  2. Remove radiator support cover. Remove CPA clip and disconnect front-end discriminating sensor harness connector. Remove sensor fasteners and sensor from radiator support. (Scheme 16)
  1. Align sensor to vehicle, ensuring arrow on sensor body is pointing toward front of vehicle. Install and tighten sensor fasteners to 98 INCH lbs. (11 N.m). Install sensor pigtail clips. Reconnect harness connector and reinstall CPA clip. Install radiator support cover.
  2. Activate air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system) . Check system for proper operation. See «SYSTEM OPERATION CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__system-operation-check) .

Scheme 16

Scheme 16
Scheme 16
  1. Before proceeding, see «SERVICE PRECAUTIONS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system).
  2. Remove appropriate door trim panel. Remove side impact sensing module fasteners. (Scheme 17) Remove side impact sensing module.
  1. Ensure door water deflector is installed. Mount sensor module on vehicle with arrow pointing toward front of vehicle. Install fasteners and tighten to 80 INCH lbs. (9 N.m). Install door trim panel.
  2. Activate air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system) . Check system for proper operation. See «SYSTEM OPERATION CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__system-operation-check) .

Scheme 17

Scheme 17
Scheme 17
  1. Before proceeding, see «SERVICE PRECAUTIONS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__service-precautions) . Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system) .
  2. Remove driver-side air bag module. See «AIR BAG MODULES»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) . Remove steering wheel nut. Note mark on steering shaft and steering wheel to ensure proper alignment during installation. Using Steering Wheel Puller (J-1859-A) and Steering Wheel Puller Legs (J-42578), remove steering wheel.
  1. To install, feed coil assembly wiring through steering wheel. Align mark on steering wheel with mark on shaft, then install nut. Tighten nut to 30 ft. lbs. (41 N.m). Install driver-side air bag module. See «AIR BAG MODULES»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) .
  2. Activate air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system) . Check system for proper operation. See «SYSTEM OPERATION CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__system-operation-check) .
  1. Before proceeding, see «SERVICE PRECAUTIONS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system).
  2. Ensure front wheels face straight ahead. Remove driver-side air bag module. See «AIR BAG MODULES»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). Remove steering wheel. See «STEERING WHEEL»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). Remove coil assembly retaining ring. Let coil hang freely. (Scheme 18)
  3. Remove wave washer. Using Lock Plate Compressor (J-23653-C), push down shaft lock. Remove shaft lock retaining ring and shaft lock. Remove turn signal canceling cam assembly. Remove upper bearing spring, inner race seat and inner race. Turn signal to RIGHT TURN position (up). Remove multi-function lever and hazard knob assembly.
  4. Remove bolts and signal switch arm. Remove turn signal switch bolts. Disconnect turn signal switch connector from wire harness, remove wiring protector, nut and disconnect ground wire. Gently pull wire harness through column and remove turn signal switch assembly.
  5. Remove wiring protector from SIR coil assembly wire harness. Attach mechanic's wire to terminal connectors to aid reassembly. Gently pull wire through column.

Note. Coil assembly will become uncentered if column is separated from steering gear and allowed to rotate, or if centering spring is depressed, allowing hub to rotate while coil assembly is removed from column.

  1. Feed coil assembly wire harness through steering column. Allow coil assembly to hang freely. Install wiring protector. Connect coil assembly wire harness connector to turn signal switch wire harness. Install turn signal switch assembly and tighten screws to 31 INCH lbs. (3.5 N.m). Install signal switch arm. Tighten round washer head screw to 27 INCH lbs. (3 N.m) and flat head tapping screw to 22 INCH lbs. (2.5 N.m).
  2. Install multifunction lever and hazard knob assembly. Install inner race, upper bearing inner race seat and spring. Install turn signal canceling cam assembly and shaft lock. Using Lock Plate Compressor (J-23653-C), align block tooth on shaft, depress shaft lock and install new shaft lock retaining ring. Install wave washer.
  3. Ensure SIR coil assembly hub is centered. Install coil assembly, pulling wires tight while positioning coil on steering shaft. Align opening in coil with horn tower and projections between two tabs on housing cover. Seat coil on steering column and install coil assembly retaining ring.
  4. Install steering wheel. See «STEERING WHEEL»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) . Install driver-side air bag module. See «AIR BAG MODULES»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) . Activate air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system) . Check system for proper operation. See «SYSTEM OPERATION CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__system-operation-check) .

Scheme 18

Scheme 18
Scheme 18

Removal (Driver-Side)

  1. Before proceeding, see «SERVICE PRECAUTIONS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system).
  2. Loosen screws from back of steering wheel until disengaged from air bag. (Scheme 19) Remove air bag from steering wheel. Disconnect horn contact by pushing slightly and twisting counterclockwise. Disconnect CPA clip and coil assembly connector from air bag module. Remove air bag module.
  1. Turn ignition off. Connect horn contact to steering column. Connect coil assembly connector and CPA clip to air bag module. Install air bag module to steering wheel, ensuring no wires are pinched. Tighten air bag module screws through back of steering wheel to 27 INCH lbs. (3 N.m).
  2. Activate air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system) . Check system for proper operation. See «SYSTEM OPERATION CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__system-operation-check) .

Scheme 19

Scheme 19
Scheme 19

Removal (Passenger-Side)

  1. Before proceeding, see «SERVICE PRECAUTIONS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system).
  2. Remove defroster grilles. Remove front A/C vent grilles. Remove 7 fasteners securing upper trim pad. Remove instrument panel upper trim pad. Remove glove box door and glove box from instrument panel.
  3. Remove air bag module fasteners. Remove passenger-side air bag module. (Scheme 20)
  1. Turn ignition off. Install air bag module. Tighten air bag module fasteners to 18 INCH lbs. (2 N.m). Install instrument panel upper trim pad. Install glove box.
  2. Activate air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system) . Check system for proper operation. See «SYSTEM OPERATION CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__system-operation-check) .

Scheme 20

Scheme 20
Scheme 20
  1. Before proceeding, see «SERVICE PRECAUTIONS»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system).
  2. Remove appropriate door trim panel. Remove air bag module fasteners. Remove side impact air bag module from door. (Scheme 21)

Install air bag module to door. Tighten air bag module fasteners to 80 INCH lbs. (9 N.m). Install door trim panel. Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check system for proper operation. See SYSTEM OPERATION CHECK .

Scheme 21

Scheme 21: Installation
Scheme 21: Installation

SYSTEM OPERATION CHECK

If system is functioning normally, AIR BAG warning light flashes 7 times and then turns off when ignition switch is turned ON. System malfunction is indicated when light does not illuminate at all, light comes on while vehicle is driven, light flashes 7 times and remains on, or light does not flash but remains on when ignition switch is turned ON.

SIR system faults are usually due to a disconnected or loose electrical connector caused by previous service on vehicle. Always check SIR coil connector at base of steering column for loose or damaged wiring.

DIAGNOSIS & TESTING

WARNINGFailure to follow service precautions may result in air bag deployment and personal injury. See SERVICE PRECAUTIONS . After component replacement, check system operation. See SYSTEM OPERATION CHECK .

DIAGNOSTIC TROUBLE CODES (DTCS)

Sensing & Diagnostic Module (SDM) provides a record of DTCs, stored according to type. SDM performs diagnostic monitoring of SIR system electrical components and sets a diagnostic trouble code (DTC) when a malfunction is detected. Current DTCs are stored in SDM and are erased when fault is corrected. Current DTCs can be read using a scan tool such as Tech 2.

SCAN TOOL DIAGNOSTICS

Scan Tool (Tech 2) reads and clears current and history codes. Ensure scan tool contains correct software cartridge for SIR diagnostics. To use scan tool, connect it to DLC connector, plug in power source and turn ignition switch to RUN position. Follow scan tool manufacturer instructions for communication with SIR system. Scan tool reads serial data from SDM data line output terminals No. 5 and 17.

DIAGNOSTIC PROCEDURES

Diagnostic procedures are designed to find and repair SIR malfunctions. It is important to use diagnostic charts and follow sequence listed below

Perform SIR System Diagnostic Check

SIR System Diagnostic Check should always be starting point for any SIR diagnostics. It checks for proper AIR BAG warning light operation and SIR trouble codes using both flash code and scan tool methods.

Refer to Proper Diagnostic Chart

SIR Diagnostic System Check indicates correct chart to diagnose SIR problems. Bypassing procedures may result in extended diagnostic time, incorrect diagnosis and incorrect parts replacement.

Repeat SIR Diagnostic System Check

Performing SIR Diagnostic System Check after all repair or diagnostic procedures ensures that repair has been made correctly and that no other conditions exist.

DIAGNOSTIC TESTS

Trouble CodePossible Cause
B1115Passenger Deployment Loop Resistance High
B1116Passenger Deployment Loop Resistance Low
B1117Passenger Deployment Loop Open
B1121Driver Deployment Loop Resistance High
B1122Driver Deployment Loop Resistance Low
B1124Driver/Passenger Deployment Loop Short To Ground
B1125Driver/Passenger Deployment Loop Short To Voltage
B1126Driver Deployment Loop Open
B1135Discriminating Sensor Closed Or Short To Ground
B1136Discriminating Sensor Open Or Short To Voltage
B1147Driver's Door Air Bag System Malfunction
B1148Passenger's Door Air Bag System Malfunction
B1151Deployment Commanded (Frontal)
B1152Data Area Full
B1153Deployment Commanded With Loop Malfunction
B1155SDM Calibration Mismatch
B1159Loss Of Serial Data Key Not Received)
B1160Loss Of Serial Data VIN Not Received)
B1163Loss Of Serial Data No Warning Light Response)
B1171Internal SDM Malfunction
B1327IGN 1 Voltage Low
B1328IGN 1 Voltage High
U1096Loss Of IPC Data Communication
U1255Class 2 Initialization Error
U1300Class 2 Short To Ground
U1301Class 2 Short To Voltage

DIAGNOSTIC TROUBLE CODE (DTC) CHART

SIR DIAGNOSTIC SYSTEM CHECK

WARNINGTo avoid air bag deployment and injury when trouble shooting system, only use test equipment specified in diagnostic charts. Carefully follow all instructions.

Circuit Description

When ignition switch is turned to RUN position, IGNITION POSITIVE VOLTAGE is applied from SIR fuse to SDM at IGNITION POSITIVE VOLTAGE input terminal No. 3 and Instrument Panel Cluster (IPC). SDM responds by flashing AIR BAG warning light 7 times then turning off while performing tests on SIR system. If SDM detects no malfunctions, SDM commands IPC to turn off AIR BAG warning light. If malfunction is detected, SDM commands IPC to turn AIR BAG warning light on. If IPC receives no message from SDM, IPC turns warning light on.

Diagnostic Aids

The order in which diagnostic trouble codes are diagnosed is very important. Failure to diagnose trouble codes in order specified may result in extended diagnostic time, incorrect diagnosis and parts replacement. If AIR BAG warning light does not flash 7 times when ignition switch is turned to RUN position, IPC is not operating correctly. If scan tool cannot communicate with SDM, class 2 serial data line may be damaged. If a State Of Health (SOH) DTC is present, refer to Diagnostic aids for that specific SOH DTC.

Diagnostic Procedure

  1. Reconnect all previously disconnected SIR system connectors. Connect scan tool to DLC. Turn ignition on. If scan tool communicates with SDM, go to step 3). If scan tool does not communicate with SDM, go to next step.
  2. Check scan tool communication with other modules (PCM, SBM, etc.). If scan tool communicates with other modules, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) . If scan tool does not communicates with other modules, check communication system.
  3. Record displayed DTCs. If only history DTCs exist, refer to Diagnostic Aids for specific DTC. A history DTC indicates malfunction has been repaired or is intermittent. If any DTCs exist, go to specified DTC. If no DTCs exist, go to next step.
  4. Observe AIR BAG warning light while turning ignition on. If AIR BAG warning light does not flash 7 times, go to next step. If AIR BAG warning light flashes 7 times, system is okay at this time.
  5. If AIR BAG warning light comes on and stays on, go to «LIGHT FLASHES 7 TIMES»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) , STAYS ON, NO DTCS SET. If not, check instrument cluster for correct operation.

When ignition switch is turned to RUN position, IGNITION POSITIVE VOLTAGE is applied to Instrument Panel Cluster (IPC). SDM responds by flashing AIR BAG warning light 7 times. At this time, SDM performs POWER-ON tests followed by RESISTANCE MEASUREMENT test and CONTINUOUS MONITORING tests. If SDM detects malfunction, SDM commands IPC to turn AIR BAG warning light on. SDM clears current diagnostic trouble codes and moves them to a history file when malfunction is no longer detected or ignition switch is cycled, except for DTCs B1151, B1152, 1153 and B1171. DTCs B1151 and B1153 can only be cleared using scan tool CLEAR CODES. DTC B1152 clears from current DTCs to enable diagnosis, but latches as a history DTC. DTC B1171 may not clear after CLEAR CODES is received.

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  2. Turn ignition off. Reconnect all SIR components and ensure all components are properly mounted. Wait 30 seconds after ignition is turned off. Turn ignition on and observe air bag warning light. If light flashes 7 times and goes off, symptom or DTC is no longer occurring. Clear SIR DTCs and repeat «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) . If light does not flash 7 times and go off, go to next step. NOTE: It is extremely unlikely that a malfunctioning SDM would cause a new malfunction to occur during diagnostic process.
  3. Using scan tool, read DTC display. If same symptom or DTC occurs as when SIR Diagnostic System Check was first performed, go to next step. If not, refer to diagnostic procedure for appropriate malfunction.
  4. Clear SIR DTCs. Turn ignition off and wait 30 seconds. Turn ignition on and observe air bag warning light. If light flashes 7 times and goes off, symptom or DTC is no longer occurring. Clear SIR DTCs and repeat «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) . If light does not flash 7 times and go off, go to next step.
  5. Turn ignition off. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation) .
  6. Reconnect all SIR components and ensure all components properly mounted. Repeat «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .

When ignition switch is turned to RUN position, IGNITION POSITIVE VOLTAGE is applied from SIR fuse to SDM at IGNITION POSITIVE VOLTAGE input terminal No. 3 and instrument panel cluster (IPC). IPC responds by flashing AIR BAG warning light 7 times then turning off while performing tests on SIR system. If SDM detects no malfunctions, SDM commands IPC to turn off AIR BAG warning light. If malfunction is detected, SDM commands IPC to turn AIR BAG warning light on. IPC turns warning light on if no message is received from SDM.

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  2. Using scan tool, enter INSTRUMENT PANEL CLUSTER SPECIAL FUNCTIONS. Follow screen prompts to WOW INSTRUMENT PANEL. In WOW MODE, turn instrument panel cluster indicators on then off again. If AIR BAG warning light operates as commanded, go to next step. If AIR BAG warning light does not operate as commanded, go to step 4).
  3. Replace SDM. See «SENSING & DIAGNOSTIC MODULE (SDM)»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) under REMOVAL & INSTALLATION. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  4. Check Instrument Panel Cluster (IPC) for correct operation. Replace as necessary. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .

When ignition switch is turned to RUN position, SDM performs tests to diagnose critical internal malfunctions. IGNITION POSITIVE VOLTAGE and deployment voltages are measured to ensure they are within normal ranges. SDM then performs RESISTANCE MEASUREMENT test. PASSENGER FRONTAL LOW terminal No. 8 is grounded through an internal current sink, and PASSENGER FRONTAL HIGH terminal No. 7 is connected to an internal constant current source. By monitoring voltage difference between PASSENGER FRONTAL HIGH and PASSENGER FRONTAL LOW, SDM calculates resistance of passenger frontal deployment loop.

Conditions For Setting DTC

When driver and passenger deployment loops are not open or shorted to voltage, passenger deployment loop is not shorted to ground, and resistance is greater than 3 ohms during RESISTANCE MEASUREMENT test. This test is run once each ignition cycle when IGNITION POSITIVE VOLTAGE is within normal operating range.

Action Taken

SDM sets DTC and commands IPC to turn on AIR BAG warning light.

Conditions For Clearing DTC

Current DTC clears when ignition switch is cycled and resistance is less than 3 ohms. History DTC clears when scan tool CLEAR CODES is received or when 250 malfunction-free ignition cycles have occurred. If CLEAR CODES is received, and DTC is still present, DTC will not reappear until next ignition cycle.

An intermittent condition is likely to be caused by a poor connection at passenger-side air bag connector terminals "A" or "B", SDM terminals No. 7 or 8, or a poor wire to terminal connection in circuits 1403 or 1404.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Check for proper connection at terminals "A" and "B" on passenger-side air bag Yellow 2-pin harness connector. (Scheme 5) If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 5).
  3. Replace passenger-side air bag Yellow 2-pin harness connector. Go to next step.
  4. Check for proper connection at terminals "A" and "B" on passenger-side air bag Yellow 2-pin harness connector. (Scheme 5) If terminals are damaged or corroded, go to step 7). If terminals are okay, go to step 20).
  5. Check for proper connection at terminals "A" and "B" on passenger-side air bag Yellow 2-pin harness connector. (Scheme 5) If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 7).
  6. Replace passenger-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 20).
  7. Reconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Turn ignition on. If DTC B1115 is present, go to step 9). If DTC B1115 is not present, go to next step.
  8. Turn ignition off. Replace passenger-side air bag connector. Go to step 20).
  9. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Install SIR Driver/Passenger Load Tool (J-38715-A) to harness connectors. Turn ignition on. If DTC B1115 is present, go to step 11). If DTC B1115 is not present, go to next step.
  10. Turn ignition off. Replace passenger-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 20).
  11. Disconnect SDM. (Scheme 15) Disconnect SIR driver/passenger load tool from harness connectors. Inspect for proper connection at SDM harness connector terminals No. 7 and 8. (Scheme 1) If harness connector is damaged or corroded, go to next step. If harness connector is okay, go to step 14).
  12. Replace SDM harness connector. Go to next step.
  13. Inspect SDM terminals No. 7 and 8. (Scheme 1) If terminals are damaged or corroded, go to step 15). If terminals are okay, go to step 20).
  14. Inspect SDM terminals No. 7 and 8. (Scheme 1) If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 16).
  15. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 20).
  16. Zero Digital Multimeter (J-39200). Measure resistance between SDM harness connector terminal No. 7 and passenger-side air bag Yellow 2-pin harness connector terminal "A". (Scheme 1)and (Scheme 5). If resistance is 0-0.5 ohms, go to step 19). If resistance is greater than 0.5 ohms, go to next step.
  17. Repair high resistance condition in circuit 1403. Go to step 20).
  18. Measure resistance between SDM harness connector terminal No. 8 and passenger-side air bag Yellow 2-pin harness connector terminal "B". (Scheme 1)and (Scheme 5). If resistance is 0-0.5 ohms, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If resistance is greater than 0.5 ohms, go to next step.
  19. Repair high resistance condition in circuit 1404. Go to next step.
  20. Reconnect all SIR components. Ensure that all components are properly mounted. Go to next step.
  21. Clear all SIR DTCs. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, SDM performs tests to diagnose critical internal malfunctions. IGNITION POSITIVE VOLTAGE and deployment voltages are measured to ensure they are within normal ranges. SDM then performs RESISTANCE MEASUREMENT test. PASSENGER FRONTAL LOW terminal No. 8 is grounded through an internal current sink, and PASSENGER FRONTAL HIGH terminal No. 7 is connected to an internal constant current source. By monitoring voltage difference between PASSENGER FRONTAL HIGH and PASSENGER FRONTAL LOW, SDM calculates combined resistance of passenger frontal deployment loop using measured voltage.

DTC sets when driver and passenger deployment loops are not open, shorted to voltage or shorted to ground, and passenger deployment loop resistance is less than 1.4 ohms. Test occurs only once each ignition cycle when IGNITION POSITIVE VOLTAGE is within normal operating range.

SDM sets DTC and commands IPC to turn on AIR BAG warning light.

Current DTC clears when ignition switch is cycled and resistance is greater than 1.4 ohms. History DTC clears when scan tool CLEAR CODES is received or when 250 malfunction-free ignition cycles have occurred. If CLEAR CODES is received, and DTC is still present, DTC will not reappear until next ignition cycle.

An intermittent condition is likely to be caused by a short between circuit 1403 and circuits 347, 348, or 1404, or a malfunctioning shorting bar on passenger-side air bag connector.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Follow scan tool instructions to request SIR data list display. Read and record passenger deployment loop resistance. If DTC B1122 is also indicated, go to next step. If DTC B1122 is not indicated, go to step 4).
  3. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Repair short between circuits 347 and 1403. Go to step 11).
  4. Turn ignition off. Disconnect passenger-side air bag Yellow 2-pin connector located behind glove box. (Scheme 9) Reconnect air bag connector and ensure CPA is installed correctly. Turn ignition on. Retrieve DTCs. If DTC B1116 is present, go to next step. If DTC B1116 is not present, go to step 11).
  5. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Install SIR Driver/Passenger Load Tool (J-38715-A) to harness connectors. Turn ignition on. Retrieve DTCs. If DTC B1116 is present, go to step 7). If DTC B1116 is not present, go to next step.
  6. Turn ignition off. Replace passenger-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 11).
  7. Turn ignition off. Disconnect SDM. (Scheme 15) Disconnect SIR driver/passenger load tool from harness connectors. Measure resistance between SDM harness connector terminals No. 7 and 8. (Scheme 1) If resistance is less than infinite, go to next step. If resistance is infinite, go to step 9).
  8. Turn ignition off. Repair short between circuits 1403 and 1404. Go to step 11).
  9. Measure resistance between SDM harness connector terminals No. 8 and 9. (Scheme 1) If resistance is less than infinite, go to next step. If resistance is infinite, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system).
  10. Repair short between circuits 1403 and 348. Go to next step.
  11. Reconnect all SIR components. Ensure that all components are properly mounted. Go to next step.
  12. Clear all SIR DTCs. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, SDM performs tests to diagnose critical internal malfunctions. SDM measures to ensure IGNITION POSITIVE VOLTAGE is within normal range. SDM then performs DEPLOYMENT LOOP CONTINUITY test, measuring voltage difference between PASSENGER FRONTAL HIGH and PASSENGER FRONTAL LOW.

DTC sets when voltage difference between PASSENGER FRONTAL HIGH terminal No. 7 and PASSENGER FRONTAL LOW terminal No. 8 is greater than or equal to 426 millivolts for 500 milliseconds during DEPLOYMENT LOOP CONTINUITY, RESISTANCE MEASUREMENT, or CONTINUOUS MONITORING tests.

SDM sets DTC and commands IPC to turn on AIR BAG warning light.

Current DTC clears when voltage difference between PASSENGER FRONTAL HIGH terminal No. 7 and PASSENGER FRONTAL LOW terminal No. 8 is less than 426 millivolts for 500 milliseconds. History DTC clears when scan tool CLEAR CODES is received or 250 malfunction-free ignition cycles have occurred.

An intermittent condition is likely to be caused by a poor connection at passenger-side air bag connector terminals "A" or "B", SDM terminals No. 7 or 8, or an open in circuits 1403 or 1404.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Follow scan tool instructions to request SIR data list display. Read and record passenger deployment loop voltage difference PASSENGER VDIF. Go to next step.
  3. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Check for proper connection at terminals "A" and "B" on harness side of passenger-side air bag Yellow 2-pin connector. (Scheme 5) If terminals are damage or corroded, go to next step. If okay, go to step 6).
  4. Replace passenger-side air bag harness Yellow 2-pin connector. Go to next step.
  5. Check for proper connection at passenger-side air bag harness Yellow 2-pin connector terminals "A" and "B". (Scheme 5) If terminals are damaged or corroded, go to step 7). If terminals are okay, go to step 21).
  6. Check for proper connection at passenger-side air bag harness Yellow 2-pin connector terminals "A" and "B". (Scheme 5) If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 8).
  7. Replace passenger-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 21).
  8. Connect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Turn ignition on. Follow scan tool instructions to request SIR data list display. Read and record passenger deployment loop voltage difference PASSENGER VDIF. If PASSENGER VDIF is less than 426 millivolts, go to next step. If PASSENGER VDIF is 426 millivolts or greater, go to step 10).
  9. Turn ignition off. Replace passenger-side air bag harness Yellow 2-pin connector. Go to step 21).
  10. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located above wiring junction box on left and right side of instrument panel. (Scheme 8)and (Scheme 9). Install SIR Driver/Passenger Load Tool (J-38715-A) to harness connectors. Turn ignition on. Using scan tool, request SIR data list display. Read and record passenger deployment loop voltage difference PASSENGER VDIF. If PASSENGER VDIF is less than 426 millivolts, go to next step. If PASSENGER VDIF is 426 millivolts or greater, go to step 12).
  11. Turn ignition off. Replace passenger-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 21).
  12. Inspect for proper connection at SDM harness connector terminals No. 7 and 8. (Scheme 1) If terminals are damaged or corroded, go to next step. If terminals are not damaged or corroded, go to step 15).
  13. Replace SDM harness connector. Go to next step.
  14. Inspect for proper connection at SDM harness connector terminals No. 7 and 8. (Scheme 1) If terminals are damaged or corroded, go to step 16). If terminals are not damaged or corroded, go to step 21).
  15. Inspect for proper connection at SDM harness connector terminals No. 7 and 8. (Scheme 1) If terminals are damaged or corroded, go to next step. If terminals are not damaged or corroded, go to step 17).
  16. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 21).
  17. Zero Digital Multimeter (J-39200). Measure resistance between SDM harness connector terminal No. 8 and passenger-side air bag Yellow 2-pin harness connector terminal "B". (Scheme 1)and (Scheme 5). If resistance is 0.5 ohms, go to step 19). If resistance is greater than 0.5 ohms, go to next step.
  18. Repair high resistance condition in circuit 1403. Go to step 21).
  19. Measure resistance between SDM harness connector terminal No. 7 and passenger-side air bag Yellow 2-pin harness connector terminal "A". (Scheme 1)and (Scheme 5). If resistance is 0.5 ohms, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If resistance is greater than 0.5 ohms, go to next step.
  20. Repair high resistance condition in circuit 1404. Go to next step.
  21. Reconnect all SIR components. Ensure that all components are properly mounted. Go to next step.
  22. Clear all SIR DTCs. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, SDM performs tests to diagnose critical internal malfunctions. IGNITION POSITIVE VOLTAGE and deployment loop voltages are measured to ensure they are within normal ranges. SDM then performs RESISTANCE MEASUREMENT test. DRIVER FRONTAL LOW terminal No. 9 is grounded through an internal current sink and a constant current source is connected to DRIVER FRONTAL HIGH terminal No. 10. By monitoring voltage difference between DRIVER FRONTAL HIGH and DRIVER FRONTAL LOW, SDM calculates resistance of driver deployment loop using measured voltage.

DTC sets when driver and passenger deployment loops are not open or shorted to voltage, driver deployment loop is not shorted to ground, and resistance is greater than 3.8 ohms during RESISTANCE MEASUREMENT test. Test is run once each ignition cycle when IGNITION POSITIVE VOLTAGE is within normal operating range.

SDM sets DTC and commands IPC to turn on AIR BAG warning light.

Current DTC clears when driver deployment loop resistance is less than 3.8 ohms and ignition switch is cycled. History DTC clears when scan tool CLEAR CODES is received or 250 malfunction-free ignition cycles have occurred. When scan tool CLEAR CODES is received and fault still exists, DTC will not reappear until next ignition cycle.

An intermittent condition is likely to be caused by a poor connection at driver-side air bag module or SIR coil assembly harness connector terminals "A" or "B", SDM terminals No. 9 or 10, or a poor wire to terminal connection in circuit 347 or 348.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Check for proper connection at terminals "A" and "B" on driver-side air bag Yellow 2-pin harness connector. (Scheme 4) If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 5).
  3. Replace driver-side air bag Yellow 2-pin harness connector. Go to next step.
  4. Check for proper connection at terminals "A" and "B" on SIR coil side of connector. (Scheme 4) If terminals are damaged or corroded, go to step 6). If terminals are okay, go to step 22).
  5. Check for proper connection at terminals "A" and "B" on SIR coil side of connector. (Scheme 4) If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 7).
  6. Replace SIR coil. See SIR COIL ASSEMBLY under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 22).
  7. Reconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Turn ignition on. Retrieve DTCs. If DTC B1121 is present, go to step 9). If DTC B1121 is not present, go to next step.
  8. Turn ignition off. Replace driver-side Yellow 2-pin harness connector. Go to step 22).
  9. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Install SIR Driver/Passenger Load Tool (J-38715-A) to harness connectors. Turn ignition on. Retrieve DTCs. If DTC B1121 is present, go to step 13). If DTC B1121 is not present, go to next step.
  10. Turn ignition off. Remove driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Install SIR Driver/Passenger Load Tool (J-38715-A) to upper SIR connector on steering column. Turn ignition on. Retrieve DTCs. If DTC B1121 is present, go to step 12). If DTC B1121 is not present, go to next step.
  11. Turn ignition off. Replace driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 22).
  12. Replace SIR coil. See SIR COIL ASSEMBLY under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 22).
  13. Turn ignition off. Disconnect SDM. (Scheme 15) Disconnect SIR driver/passenger load tool from harness connectors. Inspect for proper connection at SDM harness connector terminals No. 2 and 3. (Scheme 1) If harness connector is damaged or corroded, go to next step. If harness connector is okay, go to step 16).
  14. Replace SDM harness connector. Go to next step.
  15. Inspect for proper connection at SDM terminals No. 9 and 10. (Scheme 1) If terminals are damaged or corroded, go to step 17). If terminals are okay, go to step 22).
  16. Inspect for proper connection at SDM harness connector terminals No. 9 and 10. (Scheme 1) If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 18).
  17. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 22).
  18. Measure resistance between SDM harness connector terminal No. 10 and driver-side air bag Yellow 2-pin harness connector terminal "A". (Scheme 1)and (Scheme 4). If resistance is 0-0.5 ohms, go to step 20). If resistance is greater than 0.5 ohms, go to next step.
  19. Repair high resistance condition in circuit 347. Go to step 22).
  20. Measure resistance between SDM harness connector terminal No. 9 and driver-side air bag Yellow 2-pin harness connector terminal "B". If resistance is 0-0.5 ohms, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If resistance is greater than 0.5 ohms, go next step.
  21. Repair high resistance condition in circuit 348. Go next step.
  22. Reconnect all SIR components. Ensure that all components are properly mounted. Go to next step.
  23. Clear all SIR DTCs. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, SDM performs tests to diagnose critical internal malfunctions. IGNITION POSITIVE VOLTAGE and deployment loop voltages are measured to ensure they are within normal ranges. SDM then performs RESISTANCE MEASUREMENT test. DRIVER FRONTAL LOW terminal No. 9 is grounded through a current sink and an internal constant current source is connected to DRIVER FRONTAL HIGH terminal No. 10. By monitoring the voltage difference between DRIVER FRONTAL HIGH and DRIVER FRONTAL LOW, SDM calculates resistance of driver frontal deployment loop using measured voltage.

DTC sets when driver and passenger deployment loops are not open or shorted to voltage, driver deployment loop is not shorted to ground, and resistance is less than 1.7 ohms during RESISTANCE MEASUREMENT test. Test is run once each ignition cycle when IGNITION POSITIVE VOLTAGE is within normal operating range.

SDM sets DTC and commands IPC to turn on AIR BAG warning light.

Current DTC clears when driver deployment loop resistance is greater than 1.7 ohms and ignition switch is cycled. History DTC clears when scan tool CLEAR CODES is received or 250 malfunction-free ignition cycles have occurred. When scan tool CLEAR CODES is received and fault still exists, DTC will not reappear until next ignition cycle.

An intermittent condition is likely to be caused by a short between circuit 347 and circuits 348, 1403, or 1404, or a malfunctioning shorting bar on driver-side air bag connector or SIR coil connector.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Follow scan tool instructions to request SIR data list display. Read and record driver deployment loop resistance. If DTC B1116 is also indicated, go to next step. If DTC B1116 is not indicated, go to step 4).
  3. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Repair short between circuits 347 and 1403. Go to step 13).
  4. Turn ignition off. Disconnect driver-side air bag Yellow 2-pin connector located at base of steering column. (Scheme 8) Reconnect 2-pin connector. Inspect CPA for proper installation. Turn ignition on. Retrieve DTCs. If DTC B1122 is present, go to next step. If DTC B1122 is not present, go to step 13).
  5. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Install SIR Driver/Passenger Load Tool (J-38715-A) to harness connectors. Turn ignition on. Retrieve DTCs. If DTC B1122 is present, go to step 9). If DTC B1122 is not present, go to next step.
  6. Turn ignition off. Remove driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Install SIR Driver/Passenger Load Tool (J-38715-A) to upper SIR connector on steering column. Turn ignition on. Retrieve DTCs. If DTC B1122 is present, go to step 8). If DTC B1122 is not present, go to next step.
  7. Turn ignition off. Replace driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 13).
  8. Turn ignition off. Replace SIR coil. See SIR COIL ASSEMBLY under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 13).
  9. Turn ignition off. Disconnect SDM. (Scheme 15) Disconnect SIR driver/passenger load tool from harness connectors. Measure resistance between SDM harness connector terminals No. 9 and 10. (Scheme 1) If resistance is less than infinite, go to next step. If resistance is infinite, go to step 11).
  10. Repair short between circuits 347 and 348. Go to step 13).
  11. Measure resistance between SDM harness connector terminals No. 8 and 10. (Scheme 1) If resistance is less than infinite, go to next step. If resistance is infinite, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system).
  12. Repair short between circuits 347 and 1404. Go to next step.
  13. Reconnect all SIR components. Ensure that all components are properly mounted. Go to next step.
  14. Clear all SIR DTCs. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, SDM performs tests to diagnose critical internal malfunctions. IGNITION POSITIVE VOLTAGE, 23 VLR and deployment loop voltages are measured to ensure they are within normal ranges. SDM monitors voltages at DRIVER FRONTAL LOW terminal No. 9 and PASSENGER FRONTAL LOW terminal No. 8 to detect shorts to ground in air bag module circuits.

DTC sets when driver and passenger deployment loops are not open, and voltage at DRIVER FRONTAL LOW terminal No. 9 or PASSENGER FRONTAL LOW terminal No. 8 is less than 2.2 volts for 500 milliseconds during POWER-ON, RESISTANCE MEASUREMENT, or CONTINUOUS MONITORING tests while IGNITION POSITIVE VOLTAGE is within normal operating voltage range.

SDM sets DTC and commands IPC to turn on AIR BAG warning light.

Current DTC clears when voltage at DRIVER FRONTAL LOW and PASSENGER FRONTAL LOW is greater than 2.2 volts for 500 milliseconds and ignition switch is cycled. History DTC clears when scan tool CLEAR CODES is received or 250 malfunction-free ignition cycles have occurred.

An intermittent condition is likely to be caused by a short to ground in driver-side air bag module circuit. Inspect circuits 347, 348, 1403 and 1404 carefully for cutting or chafing. Note and compare value of driver deployment loop resistance over multiple ignition cycles to determine intermittent condition. An intermittent open in SIR coil assembly could also set this DTC. To test for bad SIR coil assembly, clear DTCs, then turn steering wheel back and forth with ignition switch in RUN position. If DRIVER SENSELO changes while turning steering wheel, SIR coil assembly is probably malfunctioning.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. Connect scan tool to DLC. Turn ignition on. Using scan tool, request SIR data list display. Read driver low voltage DRIVER SENSELO. If voltage is less than 2.2 volts, go to next step. If voltage is 2.2 volts or greater, go to step 17).
  3. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Install SIR Driver/Passenger Load Tool (J-38715-A) to harness connectors. Turn ignition on. Using scan tool, request SIR data list display. Read driver low voltage DRIVER SENSELO. If voltage is less than 2.2 volts, go to step 7). If voltage is 2.2 volts or greater, go to next step.
  4. Turn ignition off. Remove driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Disconnect SIR Driver/Passenger Load Tool (J-38715-A) from driver-side 2-pin harness connector. Connect driver-side 2-pin harness connector at base of steering column. (Scheme 8) Connect SIR driver/passenger load tool to SIR coil connector on steering column. Turn ignition on. Using scan tool, request SIR data list display. Read driver low voltage DRIVER SENSELO.If voltage is less than 2.2 volts, go to step 6). If voltage is 2.2 volts or greater, go to next step.
  5. Replace driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 18).
  6. Turn ignition off. Remove SIR coil. See SIR COIL ASSEMBLY under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Inspect coil and wires for damage. Replace SIR coil. Go to step 18).
  7. Turn ignition off. Disconnect SDM. (Scheme 15) Disconnect SIR driver/passenger load tool from harness connectors. Measure resistance between SDM harness connector terminals No. 10 and 18. (Scheme 1) If resistance is less than infinite, go to next step. If resistance is infinite, go to step 9).
  8. Repair short to ground in circuit 347. Go to step 18).
  9. Measure resistance between SDM harness connector terminals No. 9 and 18. (Scheme 1) If resistance is less than infinite, go to next step. If resistance is infinite, go to step 11).
  10. Repair short to ground in circuit 348. Go to step 18).
  11. Turn ignition off. Disconnect passenger-side Yellow 2-pin connector. (Scheme 9) Install SIR Driver/Passenger Load Tool (J-38715-A) to passenger-side 2-pin harness connector. Turn ignition on. Using scan tool, request SIR data list display. Read driver low voltage PASSENGER SENSELO. If voltage is less than 2.2 volts, go to step 13). If voltage is 2.2 volts or greater, go to next step.
  12. Replace passenger-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 18).
  13. Turn ignition off. Disconnect SDM. (Scheme 15) Disconnect SIR driver/passenger load tool from harness connectors. Measure resistance between SDM harness connector terminals No. 8 and 18. (Scheme 1) If resistance is less than infinite, go to next step. If resistance is infinite, go to step 15).
  14. Repair short to ground in circuit 1404. Go to step 18).
  15. Measure resistance between SDM harness connector terminals No. 7 and 18. (Scheme 1) If resistance is less than infinite, go to next step. If resistance is infinite, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system).
  16. Repair short to ground in circuit 1403. Go to step 18).
  17. Turn ignition off. Disable SIR system. See «DISABLING SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-system). Remove driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Install SIR Driver/Passenger Load Tool (J-38715-A) to coil and passenger-side Yellow 2-pin harness connectors. Turn ignition on. Connect driver-side Yellow 2-pin connector at base of steering column. Turn ignition on. Using Diagnostic Aids, locate intermittent short in SIR system. Repair as necessary. Go to next step.
  18. Reconnect all SIR components. Ensure that all components are properly mounted. Turn ignition on. Ensure DRIVER SENSELO and PASSENGER SENSLO is greater than 2.2 volts. Replace SDM. See «SENSING & DIAGNOSTIC MODULE (SDM)»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) under REMOVAL & INSTALLATION. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, SDM performs tests to diagnose critical internal malfunctions. IGNITION POSITIVE VOLTAGE, 23 VLR and deployment loop voltages are measured to ensure they are within normal ranges. SDM monitors voltages at DRIVER FRONTAL LOW terminal No. 9 and PASSENGER FRONTAL LOW terminal No. 8 to detect shorts to voltage in air bag module circuits.

DTC sets when voltage at PASSENGER FRONTAL LOW terminal No. 8 or DRIVER FRONTAL LOW terminal No. 9 is greater than 4.0 volts for 500 milliseconds during CONTINUOUS MONITORING test, and IGNITION POSITIVE VOLTAGE is within normal operating range.

SDM sets DTC and commands IPC to turn on AIR BAG warning light.

DTC clears when voltage at DRIVER FRONTAL LOW and PASSENGER FRONTAL LOW is less than 4.0 volts for 500 milliseconds and ignition switch is turned OFF. DTC B1171 remains current.

An intermittent condition is likely to be caused by a short to ground in driver-side air bag circuit. Inspect circuits 347, 348, 1403 and 1404 carefully for cutting or chafing. Note and compare value of driver deployment loop resistance over multiple ignition cycles to determine intermittent condition. An intermittent open in SIR coil assembly could also set this DTC. To test for bad SIR coil assembly, clear DTCs, then turn steering wheel back and forth with ignition switch in RUN position. If DRIVER SENSELO changes while turning steering wheel, SIR coil assembly is probably malfunctioning.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. Connect scan tool to DLC. Turn ignition on. Using scan tool, request SIR data list display. Read driver low voltage DRIVER SENSELO. If voltage is less than 4 volts, go to next step. If voltage is 4 volts or greater, go to step 17).
  3. Turn ignition off. Disconnect driver-side air bag Yellow 2-pin connector located at base of steering column. (Scheme 8) Install SIR Driver/Passenger Load Tool (J-38715-A) to harness connector. Turn ignition on. Using scan tool, request SIR data list display. Read driver low voltage DRIVER SENSELO. If voltage is less than 4 volts, go to step 7). If voltage is 4 volts or greater, go to next step.
  4. Turn ignition off. Remove driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Disconnect SIR Driver/Passenger Load Tool (J-38715-A) from driver-side 2-pin harness connector. Connect driver-side 2-pin harness connector at base of steering column. (Scheme 8) Connect SIR driver/passenger load tool to SIR coil connector on steering column. Turn ignition on. Using scan tool, request SIR data list display. Read driver low voltage DRIVER SENSELO.If voltage is less than 4 volts, go to step 6). If voltage is 4 volts or greater, go to next step.
  5. Replace driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 18).
  6. Turn ignition off. Remove SIR coil. See SIR COIL ASSEMBLY under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Inspect coil and wires for damage. Replace SIR coil. Go to step 18).
  7. Turn ignition off. Disconnect SDM. (Scheme 15) Disconnect SIR driver/passenger load tool from harness connectors. Turn ignition on. Measure voltage between SDM harness connector terminals No. 10 and 18. (Scheme 1) If voltage is less than one volt, go to step 9). If voltage is one volt or greater, go to next step.
  8. Repair short to voltage in circuit 347. Go to step 18).
  9. Measure voltage between SDM harness connector terminals No. 9 and 18. (Scheme 1) If voltage is less than one volt, go to step 11). If voltage is one volt or greater, go to next step.
  10. Repair short to voltage in circuit 348. Go to step 18).
  11. Turn ignition off. Disconnect passenger-side Yellow 2-pin connector behind glove box. (Scheme 9) Install SIR Driver/Passenger Load Tool (J-38715-A) to passenger-side 2-pin harness connector. Turn ignition on. Using scan tool, request SIR data list display. Read driver low voltage PASSENGER SENSELO. If voltage is less than 4 volts, go to step 13). If voltage is 4 volts or greater, go to next step.
  12. Replace passenger-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 18).
  13. Turn ignition off. Disconnect SDM. (Scheme 15) Disconnect SIR driver/passenger load tool from harness connectors. Measure voltage between SDM harness connector terminals No. 8 and 18. (Scheme 1) If voltage is one volt or greater, go to next step. If voltage is less than one volt, go to step 15).
  14. Repair short to voltage in circuit 1404. Go to step 18).
  15. Measure voltage between SDM harness connector terminals No. 7 and 18. (Scheme 1) If voltage is one volt or greater, go to next step. If voltage is less than one volt, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system).
  16. Repair short to voltage in circuit 1403. Go to step 18).
  17. Using Diagnostic Aids, locate intermittent short in SIR system. Repair as necessary. Go to next step.
  18. Reconnect all SIR components. Ensure that all components are properly mounted. Turn ignition on. Ensure DRIVER SENSELO and PASSENGER SENSLO is greater than 4 volts. Replace SDM. See «SENSING & DIAGNOSTIC MODULE (SDM)»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) under REMOVAL & INSTALLATION. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, SDM performs tests to diagnose critical internal malfunctions. SDM measures to ensure IGNITION POSITIVE VOLTAGE is within normal range. During DEPLOYMENT LOOP CONTINUITY test, SDM measures voltage difference between DRIVER FRONTAL HIGH and DRIVER FRONTAL LOW.

DTC sets when voltage difference between DRIVER FRONTAL HIGH terminal No. 10 and DRIVER FRONTAL LOW terminal No. 9 is greater than or equal to 426 millivolts for 500 milliseconds during DEPLOYMENT LOOP CONTINUITY, RESISTANCE MEASUREMENT, or CONTINUOUS MONITORING tests.

SDM sets DTC and commands IPC to turn on AIR BAG warning light.

Current DTC clears when voltage difference between DRIVER FRONTAL HIGH terminal No. 10 and DRIVER FRONTAL LOW terminal No. 9 is less than 426 millivolts for 500 milliseconds. History DTC clears when scan tool CLEAR CODES is received or 250 malfunction-free ignition cycles have occurred.

An intermittent condition is likely to be caused by a poor connection at driver-side air bag module terminals "A" or "B", SIR coil assembly terminals "A" or "B", SDM terminals No. 9 or 10, or an open in circuit 347 or 348. An intermittent open in SIR coil assembly could also set this DTC. To test for bad SIR coil assembly, clear DTCs, then turn steering wheel back and forth with ignition switch in RUN position. If AIR BAG warning light comes ON and DTC B1126 has set again, SIR coil assembly is probably malfunctioning.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. Connect scan tool to Data Link Connector (DLC). Turn ignition on. Follow scan tool instructions to request SIR data list display. Read and record driver deployment loop voltage difference DRIVER VDIF. Go to next step.
  3. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Check for proper connection at terminals "A" and "B" on harness side of driver-side air bag Yellow 2-pin connector. (Scheme 4) If terminals are damaged or corroded, go to next step. If okay, go to step 6).
  4. Replace driver-side air bag harness Yellow 2-pin connector. Go to next step.
  5. Check for proper connection at driver-side air bag harness Yellow 2-pin connector terminals "A" and "B". (Scheme 4) If terminals are damaged or corroded, go to step 7). If terminals are okay, go to step 23).
  6. Check for proper connection at driver-side air bag harness Yellow 2-pin connector terminals "A" and "B". (Scheme 4) If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 8).
  7. Replace SIR coil. See SIR COIL ASSEMBLY under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 23).
  8. Connect driver and passenger-side air bag Yellow 2-pin connectors located above wiring junction box on left and right side of instrument panel. (Scheme 8)and (Scheme 9). Turn ignition on. Follow scan tool instructions to request SIR data list display. Read and record driver deployment loop voltage difference DRIVER VDIF. If DRIVER VDIF is less than 426 millivolts, go to next step. If DRIVER VDIF is 426 millivolts or greater, go to step 10).
  9. Turn ignition off. Replace driver-side air bag harness Yellow 2-pin connector. Go to step 23).
  10. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located above wiring junction box on left and right side of instrument panel. (Scheme 8)and (Scheme 9). Install SIR Driver/Passenger Load Tool (J-38715-A) to harness connectors. Turn ignition on. Using scan tool, request SIR data list display. Read and record driver deployment loop voltage difference DRIVER VDIF. If DRIVER VDIF is less than 426 millivolts, go to next step. If DRIVER VDIF is 426 millivolts or greater, go to step 14).
  11. Turn ignition off. Remove driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Disconnect SIR Driver/Passenger Load Tool (J-38715-A) from driver-side 2-pin harness connector. Connect driver-side 2-pin harness connector above wiring junction box on left side of instrument panel. (Scheme 8) Connect SIR driver/passenger load tool to SIR coil connector on steering column. Turn ignition on. Using scan tool, request SIR data list display. Read and record driver deployment loop voltage difference DRIVER VDIF. If DRIVER VDIF is less than 426 millivolts, go to next step. If DRIVER VDIF is 426 millivolts or greater, go to step 13).
  12. Turn ignition off. Replace driver-side air bag. See AIR BAG MODULES under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 23).
  13. Turn ignition off. Replace SIR coil. See SIR COIL ASSEMBLY under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 23).
  14. Disconnect SDM. (Scheme 15) Disconnect SIR driver/passenger load tool from harness connectors. Inspect for proper connection at SDM harness connector terminals No. 9 and 10. (Scheme 1) If terminals are damaged or corroded, go to next step. If terminals are not damaged or corroded, go to step 17).
  15. Replace SDM harness connector. Go to next step.
  16. Inspect for proper connection at SDM terminals No. 9 and 10. (Scheme 1) If terminals are damaged or corroded, go to step 18). If terminals are not damaged or corroded, go to step 23).
  17. Inspect for proper connection at SDM terminals No. 9 and 10. (Scheme 1) If terminals are damaged or corroded, go to next step. If terminals are not damaged or corroded, go to step 19).
  18. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 23).
  19. Zero Digital Multimeter (J-39200). Measure resistance between SDM harness connector terminal No. 10 and driver-side air bag Yellow 2-pin harness connector terminal "A". (Scheme 1)and (Scheme 4). If resistance is 0-0.5 ohms, go to step 21). If resistance is greater than 0.5 ohms, go to next step.
  20. Repair high resistance condition in circuit 347. Go to step 23).
  21. Measure resistance between SDM harness connector terminal No. 9 and driver-side air bag Yellow 2-pin harness connector terminal "B". (Scheme 1)and (Scheme 4). If resistance is 0-0.5 ohms, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If resistance is greater than 0.5 ohms, go to next step.
  22. Repair high resistance condition in circuit 348. Go to next step.
  23. Reconnect all SIR components. Ensure that all components are properly mounted. Go to next step.
  24. Clear all SIR DTCs. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, SDM performs tests to diagnose critical internal malfunctions. IGNITION POSITIVE VOLTAGE, 23 VLR and deployment loop voltages are measured to ensure they are within normal ranges. SDM then performs CONTINUOUS MONITORING. SDM contains a resistor network connected to 5 volts, ground, and SDM front-end sensor signal terminal No. 4. One k/ohm resistor in front-end discriminating sensor, parallel to normally open switch, provides a parallel path to ground. This causes a specified percentage of voltage to appear at SDM front-end sensor signal input. This voltage is monitored to detect shorts to ground or a closed discriminating sensor.

DTC sets when SDM is configured for front-end discriminating sensor, and voltage at SENSOR FEED terminal No. 4 is less than 0.7 volts for 500 milliseconds during CONTINUOUS MONITORING while IGNITION POSITIVE VOLTAGE is within normal operating range.

SDM sets DTC and commands IPC to turn on AIR BAG warning light.

Current DTC clears when voltage at SENSOR FEED terminal No. 9 is greater than 2.4 volts for 500 milliseconds. History DTC clears when scan tool CLEAR CODES is received or 250 malfunction-free ignition cycles have occurred.

An intermittent condition is likely to be caused by a short to ground in discriminating sensor circuit. Inspect circuit 1834 carefully for cutting or chafing.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. Disconnect front-end discriminating sensor. (Scheme 16) Measure resistance between sensor terminals "A" and "B". (Scheme 2) If resistance is greater than 950 ohms, go to step 4). If resistance is 950 ohms or less, go to next step.
  3. Replace front-end discriminating sensor. See FRONT-END DISCRIMINATING SENSOR under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 8).
  4. Disconnect SDM harness connector. (Scheme 15) Measure resistance between front-end discriminating sensor harness connector terminal "A" and ground. (Scheme 2) If resistance is less than infinite, go to next step. If resistance is infinite, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system).
  5. Repair short to ground in circuit 349 between SDM connector and sensor connector. Go to next step.
  6. Reconnect all SIR components. Ensure that all components are properly mounted. Go to next step.
  7. Activate air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system). Go to step 9).
  8. Reconnect all SIR components. Ensure that all components are properly mounted. Go to next step.
  9. Clear all SIR DTCs. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, SDM performs tests to diagnose critical internal malfunctions. IGNITION POSITIVE VOLTAGE, 23 VLR and deployment loop voltages are measured to ensure they are within normal ranges. SDM then performs CONTINUOUS MONITORING. SDM contains a resistor network connected to 5 volts, ground, and to SDM sensor signal terminal No. 4. One k/ohm resistor in front-end discriminating sensor, parallel to normally open switch, provides a parallel path to ground. This causes a specified percentage of voltage to appear at SDM sensor signal input. This voltage is monitored to detect shorts to voltage or an open discriminating sensor.

DTC sets when SDM is configured for front-end discriminating sensor, voltage at SENSOR FEED terminal No. 4 is greater than 3.4 volts for 500 milliseconds during CONTINUOUS MONITORING while IGNITION POSITIVE VOLTAGE is within normal operating voltage range.

SDM sets DTC and commands IPC to turn on AIR BAG warning light.

Current DTC clears when voltage at SENSOR FEED terminal No. 4 is less than 3.4 volts for 500 milliseconds. History DTC clears when scan tool CLEAR CODES command is received or 250 malfunction free ignition cycles have occurred.

An intermittent condition is likely to be caused by a broken or chafed wire in discriminating sensor circuit. Inspect circuits 349 and 1751 carefully for cutting or chafing.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. Disconnect front-end discriminating sensor. (Scheme 16) Check for proper connection at sensor harness connector terminals "A" and "B". (Scheme 2) If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 5).
  3. Replace sensor harness connector. Go to next step.
  4. Check for proper connection at sensor harness connector terminals "A" and "B". (Scheme 2) If sensor terminals are damaged or corroded, go to step 6). If terminals are okay, go to step 19).
  5. Check for proper connection at sensor harness connector terminals "A" and "B". (Scheme 2) If sensor terminals are damaged or corroded, go to next step. If terminals are okay, go to step 7).
  6. Replace front-end discriminating sensor. See FRONT-END DISCRIMINATING SENSOR under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 27).
  7. Measure resistance between sensor terminals "A" and "B". (Scheme 2) If resistance is greater than 1050 ohms, go to step 6). If resistance is 1050 ohms or less, go to next step.
  8. Measure resistance between sensor harness connector terminal "B" and ground. (Scheme 2) If resistance is 0-5 ohms, go to step 10). If resistance is greater than 5 ohms, go to next step.
  9. Repair open in circuit 1751. Go to step 21).
  10. Disconnect SDM. (Scheme 15) Inspect SDM connector terminal No. 4. (Scheme 1) If terminal is damaged or corroded, go to next step. If terminal is okay, go to step 17).
  11. Replace SDM connector. Go to next step.
  12. Inspect SDM terminal No. 4. If terminal is damaged or corroded, go to step 14). If terminal is okay, go to step 19).
  13. Inspect SDM terminal No. 4. If terminal is damaged or corroded, go to next step. If terminal is okay, go to step 15).
  14. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 19).
  15. Measure resistance between SDM connector terminal No. 4 and discriminating sensor connector terminal "A". (Scheme 1)and (Scheme 2). If resistance is 0-5 ohms, go to step 17). If resistance is greater than 5 ohms, go to next step.
  16. Repair open in circuit 349. Go to step 19).
  17. Install SIR fuse. Turn ignition on. Measure voltage between sensor harness connector terminal "A" and ground. (Scheme 2) If voltage is less than one volt, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If voltage is one volt or greater, go to next step.
  18. Turn ignition off. Repair short to voltage in circuit 349. Go to next step.
  19. Reconnect all SIR components. Ensure that all components are properly mounted. Go to next step.
  20. Activate air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__disabling-activating-air-bag-system). Go to step 9).
  21. Reconnect all SIR components. Ensure that all components are properly mounted. Go to next step.
  22. Clear all SIR DTCs. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, Side Impact Sensing Module (SISM) will perform tests to diagnose critical internal malfunctions. The SISM then tests deployment loop for an open, short to ground or ignition, high or low resistance, or reserve energy failure condition. SISM transmits a 300-millisecond, 50 percent duty cycle, pulse width modulated signal to SDM over circuit 2107 to indicate normal operation and no malfunctions. SISM communicates that it is turning off (ignition OFF) by sending a 20 millisecond, 50 percent duty cycle, pulse width modulated signal.

DTC sets when SDM receives a pulse width signal other than specified for normal operation, or no signal. SISM performs tests during POWER-ON, CONTINUOUS MONITORING, and asynchronously.

SDM sets DTC B1147 and commands IPC to turn on AIR BAG warning light.

DTC clears when SDM receives normal operation signal from SISM, or when ignition switch is cycled. If side impact deployment occurs SISM must be replaced. History DTC clears when scan tool CLEAR CODES command is received or 250 malfunction free ignition cycles have occurred.

An intermittent condition may be caused by a poor connection in SISM, driver's door air bag module, SDM terminal No. 13, or wire to terminal connections of all circuits going to SISM.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. If driver's door air bag has been deployed, go to step 4). If not, go to next step.
  3. Inspect driver-side of vehicle and undercarriage for signs of impact. If any signs exists, go to next step. If no signs exist, go to step 5).
  4. Perform «POST-COLLISION INSPECTION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__post-collision-inspection). Go to step 43).
  5. Remove SIR fuse. Disconnect driver's door air bag connector. (Scheme 21) Check for proper connection at driver's door air bag harness Yellow 2-pin connector terminals. If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 7).
  6. Replace driver's door air bag harness Yellow 2-pin connector. Go to step 42).
  7. Check for proper connection at driver's door air bag pigtail Yellow 2-pin connector terminals. If terminals are damaged or corroded, go to step 10). If terminals are okay, go to next step.
  8. Reconnect all SIR components. Install SIR fuse. Turn ignition on. Using scan tool, retrieve DTCs. If DTC B1147 is set, go to next step. If DTC B1147 is not set, go to step 43).
  9. Turn ignition off. Remove SIR fuse. Disconnect driver's door air bag connector. (Scheme 21) Install SIR Driver/Passenger Load Tool (J-38715-A) to harness connector. Install SIR fuse. Turn ignition on. Retrieve DTCs. If DTC B1147 is set, go to step 11). If DTC B1147 is not set, go to next step.
  10. Turn ignition off. Replace driver's door air bag module. See SIDE IMPACT AIR BAG MODULE under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 43).
  11. Turn ignition off. Remove SIR fuse. Disconnect driver's door SISM harness Yellow 5-pin connector. (Scheme 17) Check for proper connection of driver's door SISM harness Yellow 5-pin connector. If SISM connector terminals are damaged or corroded, go to next step. If SISM connector terminals are okay, go to step 13).
  12. Replace driver's door SISM harness Yellow 5-pin connector. Go to step 43).
  13. Inspect driver's door SISM terminals. If SISM terminals are damaged or corroded, go to next step. If SISM terminals are okay, go to step 15).
  14. Replace driver's door SISM. See SIDE IMPACT SENSING MODULE (SISM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 43).
  15. Using Digital Multimeter (J-39200), measure resistance between driver's door SISM harness Yellow 5-pin connector terminal "C" and ground. (Scheme 3) If resistance is 0-5 ohms, go to step 17). If resistance is greater than 5 ohms, go to next step.
  16. Repair open condition in circuit 1751 between SISM and wire splice S370. Go to step 43).
  17. Using Digital Multimeter (J-39200), measure resistance between driver's door SISM harness Yellow 5-pin connector terminal "E" and both SIR fuse holder terminals. (Scheme 3) If resistance is 0-5 ohms, go to step 19). If resistance is greater than 5 ohms, go to next step.
  18. Repair open condition in circuit 1139 between SISM and wire splice S319. Go to step 43).
  19. Remove SIR Driver/Passenger Load Tool (J-38715-A) from harness connector. Using Digital Multimeter (J-39200), measure resistance between driver's door air bag harness Yellow 2-pin connector terminal "A" and ground. (Scheme 6) If resistance is 0-5 ohms, go to next step. If resistance is greater than 5 ohms, go to step 21).
  20. Repair short to ground in circuit 2106. Go to step 43).
  21. Using Digital Multimeter (J-39200), measure resistance between driver's door SISM connector terminal "A" and driver's door air bag connector terminal "B". (Scheme 3) and 21. If resistance is 0-5 ohms, go to step 23). If resistance is greater than 5 ohms, go to next step.
  22. Repair high resistance or open condition in circuit 2106. Go to step 43).
  23. Reconnect all SIR components. Install SIR fuse. Turn ignition on. Measure voltage between driver's door SISM connector terminal "A" and ground. (Scheme 3) If voltage is greater than one volt, go to next step. If voltage is one volt or less, go to step 25).
  24. Turn ignition off. Repair short to voltage in circuit 2106. Go to step 43).
  25. Measure voltage between driver's door SISM connector terminal "B" and ground. (Scheme 3) If voltage is greater than one volt, go to next step. If voltage is one volt or less, go to step 27).
  26. Turn ignition off. Repair short to voltage in circuit 2105. Go to step 43).
  27. Turn ignition off. Measure resistance between driver's door SISM connector terminal "B" and ground. (Scheme 3) If resistance is 0-5 ohms, go to next step. If resistance is greater than 5 ohms, go to step 29).
  28. Repair short to ground in circuit 2105. Go to step 43).
  29. Measure resistance between driver's door SISM connector terminal "B" and driver's door air bag connector terminal "B". (Scheme 3)and (Scheme 6). If resistance is 0-5 ohms, go to step 31). If resistance is greater than 5 ohms, go to next step.
  30. Repair open or high resistance condition in circuit 2105. Go to step 43).
  31. Measure resistance between driver's door SISM connector terminal "D" and ground. (Scheme 3) If resistance is 0-5 ohms, go to step 33). If resistance is greater than 5 ohms, go to next step.
  32. Repair short to ground in circuit 2107. Go to step 43).
  33. Reconnect all SIR components. Turn ignition on. Measure voltage between driver's door SISM connector terminal "D" and ground. If voltage is one volt or less, go to next step. If voltage is greater than one volt, go to step 35).
  34. Turn ignition off. Repair short to voltage in circuit 2107. Go to step 43).
  35. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Disconnect SDM. (Scheme 15) Inspect for proper connection at SDM harness connector terminal No. 13. (Scheme 1) If terminal is damaged or corroded, go to next step. If terminal is not damaged or corroded, go to step 37).
  36. Replace SDM harness connector. Go to step 43).
  37. Inspect SDM terminal No. 13 for damage or corrosion. (Scheme 1) If SDM terminal No. 13 is damaged or corroded, go to next step. If SDM terminal No. 13 is okay, go to step 39).
  38. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 43).
  39. Measure resistance between SDM connector terminal No. 13 and driver's door SISM connector terminal "D". If resistance is 0-5 ohms, go to step 41). If resistance is greater than 5 ohms, go to next step.
  40. Repair open or high resistance condition in circuit 2107. Go to step 43).
  41. Replace driver's door SISM. See SIDE IMPACT SENSING MODULE under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 43).
  42. Reconnect all SIR components. Install SIR fuse. While staying clear of all air bag modules, turn ignition on. Retrieve DTCs. If DTC B1147 is set, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If DTC B1147 is not set, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  43. Reconnect all SIR components. Ensure that all components are properly mounted. Clear all SIR DTCs. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

When ignition switch is turned to RUN position, SISM will perform tests to diagnose critical internal malfunctions. The SISM then tests deployment loop for an open, short to ground or ignition, high or low resistance, or reserve energy failure condition. SISM transmits a 300-millisecond, 50 percent duty cycle, pulse width modulated signal to SDM over circuit 2108 to indicate normal operation and no malfunctions. SISM communicates that it is turning off (ignition OFF) by sending a 20 millisecond, 50 percent duty cycle, pulse width modulated signal.

DTC sets when SDM receives a pulse width signal other than specified for normal operation, or no signal. SISM performs tests during POWER-ON, CONTINUOUS MONITORING, and asynchronously.

SDM sets DTC B1148 and commands IPC to turn on AIR BAG warning light.

DTC clears when SDM receives normal operation signal from SISM, or when ignition switch is cycled. If side impact deployment occurs SISM must be replaced. History DTC clears when scan tool CLEAR CODES command is received or 250 malfunction free ignition cycles have occurred.

An intermittent condition may be caused by a poor connection in SISM, passenger's door air bag module, SDM terminal No. 14, or wire to terminal connections of all circuits going to SISM.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition off. If passenger's door air bag has been deployed, go to step 4). If not, go to next step.
  3. Inspect passenger-side of vehicle and undercarriage for signs of impact. If any signs exists, go to next step. If no signs exist, go to step 5).
  4. Perform «POST-COLLISION INSPECTION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__post-collision-inspection). Go to step 43).
  5. Remove SIR fuse. Disconnect passenger's door air bag connector. (Scheme 21) Check for proper connection at passenger's door air bag harness Yellow 2-pin connector terminals. If terminals are damaged or corroded, go to next step. If terminals are okay, go to step 7).
  6. Replace passenger's door air bag Yellow 2-pin connector. Go to step 42).
  7. Check for proper connection at passenger's door air bag pigtail Yellow 2-pin connector terminals. If terminals are damaged or corroded, go to step 10). If terminals are okay, go to next step.
  8. Reconnect all SIR components. Install SIR fuse. Turn ignition on. Using scan tool, retrieve DTCs. If DTC B1148 is set, go to next step. If DTC B1148 is not set, go to step 43).
  9. Turn ignition off. Remove SIR fuse. Disconnect passenger's door air bag connector. (Scheme 21) Install SIR Driver/Passenger Load Tool (J-38715-A) to harness connector. Install SIR fuse. Turn ignition on. Retrieve DTCs. If DTC B1148 is set, go to step 11). If DTC B1148 is not set, go to next step.
  10. Turn ignition off. Replace passenger's door air bag module. See SIDE IMPACT AIR BAG MODULE under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 43).
  11. Turn ignition off. Remove SIR fuse. Disconnect passenger's door SISM harness Yellow 5-pin connector. (Scheme 17) Check for proper connection of passenger's door SISM harness Yellow 5-pin connector. If SISM connector terminals are damaged or corroded, go to next step. If SISM connector terminals are okay, go to step 13).
  12. Replace passenger's door SISM harness Yellow 5-pin connector. Go to step 43).
  13. Inspect passenger's door SISM terminals. If SISM terminals are damaged or corroded, go to next step. If SISM terminals are okay, go to step 15).
  14. Replace passenger's door SISM. See SIDE IMPACT SENSING MODULE (SISM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 43).
  15. Using Digital Multimeter (J-39200), measure resistance between passenger's door SISM harness Yellow 5-pin connector terminal "C" and ground. (Scheme 3) If resistance is 0-5 ohms, go to step 17). If resistance is greater than 5 ohms, go to next step.
  16. Repair open condition in circuit 1751 between SISM and wire splice S370. Go to step 43).
  17. Using Digital Multimeter (J-39200), measure resistance between passenger's door SISM harness Yellow 5-pin connector terminal "E" and both SIR fuse holder terminals. (Scheme 3) If resistance is 0-5 ohms, go to step 19). If resistance is greater than 5 ohms, go to next step.
  18. Repair open condition in circuit 1139 between SISM and wire splice S319. Go to step 43).
  19. Remove SIR Driver/Passenger Load Tool (J-38715-A) from harness connector. Using Digital Multimeter (J-39200), measure resistance between passenger's door air bag harness Yellow 2-pin connector terminal "A" and ground. (Scheme 6) If resistance is 0-5 ohms, go to next step. If resistance is greater than 5 ohms, go to step 21).
  20. Repair short to ground in circuit 2104. Go to step 43).
  21. Using Digital Multimeter (J-39200), measure resistance between passenger's door SISM connector terminal "A" and passenger's door air bag connector terminal "B". (Scheme 3) and 21. If resistance is 0-5 ohms, go to step 23). If resistance is greater than 5 ohms, go to next step.
  22. Repair high resistance or open condition in circuit 2104. Go to step 43).
  23. Reconnect all SIR components. Install SIR fuse. Turn ignition on. Measure voltage between passenger's door SISM connector terminal "A" and ground. (Scheme 3) If voltage is greater than one volt, go to next step. If voltage is one volt or less, go to step 25).
  24. Turn ignition off. Repair short to voltage in circuit 2104. Go to step 43).
  25. Measure voltage between passenger's door SISM connector terminal "B" and ground. (Scheme 3) If voltage is greater than one volt, go to next step. If voltage is one volt or less, go to step 27).
  26. Turn ignition off. Repair short to voltage in circuit 2103. Go to step 43).
  27. Turn ignition off. Measure resistance between driver's door SISM connector terminal "B" and ground. (Scheme 3) If resistance is 0-5 ohms, go to next step. If resistance is greater than 5 ohms, go to step 29).
  28. Repair short to ground in circuit 2103. Go to step 43).
  29. Measure resistance between passenger's door SISM connector terminal "B" and passenger's door air bag connector terminal "B". (Scheme 3)and (Scheme 6). If resistance is 0-5 ohms, go to step 31). If resistance is greater than 5 ohms, go to next step.
  30. Repair open or high resistance condition in circuit 2103. Go to step 43).
  31. Measure resistance between passenger's door SISM connector terminal "D" and ground. (Scheme 3) If resistance is 0-5 ohms, go to step 33). If resistance is greater than 5 ohms, go to next step.
  32. Repair short to ground in circuit 2108. Go to step 43).
  33. Reconnect all SIR components. Turn ignition on. Measure voltage between passenger's door SISM connector terminal "D" and ground. If voltage is one volt or less, go to next step. If voltage is greater than one volt, go to step 35).
  34. Turn ignition off. Repair short to voltage in circuit 2108. Go to step 43).
  35. Turn ignition off. Disconnect driver and passenger-side air bag Yellow 2-pin connectors located at base of steering column and behind glove box. (Scheme 8)and (Scheme 9). Disconnect SDM. (Scheme 15) Inspect for proper connection at SDM harness connector terminal No. 14. (Scheme 1) If terminal is damaged or corroded, go to next step. If terminal is not damaged or corroded, go to step 37).
  36. Replace SDM harness connector. Go to step 43).
  37. Inspect SDM terminal No. 14 for damage or corrosion. (Scheme 1) If SDM terminal No. 14 is damaged or corroded, go to next step. If SDM terminal No. 14 is okay, go to step 39).
  38. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 43).
  39. Measure resistance between SDM connector terminal No. 14 and passenger's door SISM connector terminal "D". If resistance is 0-5 ohms, go to step 41). If resistance is greater than 5 ohms, go to next step.
  40. Repair open or high resistance condition in circuit 2108. Go to step 43).
  41. Replace passenger's door SISM. See SIDE IMPACT SENSING MODULE under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation). Go to step 43).
  42. Reconnect all SIR components. Install SIR fuse. While staying clear of all air bag modules, turn ignition on. Retrieve DTCs. If DTC B1148 is set, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If DTC B1148 is not set, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  43. Reconnect all SIR components. Ensure that all components are properly mounted. Clear all SIR DTCs. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).

SDM contains a sensing device which converts vehicle velocity changes to an electrical signal. Electrical signal is processed by SDM and compared to a value stored in memory. When signal exceeds stored value, additional signal processing is performed and signals are compared to values stored in memory. When 2 signals exceed stored values, SDM causes current to flow through air bag modules, deploying air bags and causing DTCs B1151 and B1152 to set.

DTC sets when SDM detects a frontal crash, up to 30 degrees off centerline of vehicle, of sufficient force to warrant deployment of air bags.

SDM sets DTCs B1151 and B1152, commands IPC to turn on AIR BAG warning light, records crash data and sends message over class 2 serial data line.

DTC clears when scan tool CLEAR CODES is received.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  2. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation) . Ensure that all components are properly mounted. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .

When SDM detects a frontal crash, up to 30 degrees off centerline of vehicle, of sufficient force to warrant deployment of air bags, DTC B1151 sets. SDM records SIR system and vehicle status in EEPROM. DTC B1152 sets when SDM attempts to store frontal crash information and finds EEPROM data area full.

DTC sets when SDM attempts to store frontal crash information and finds EEPROM data area full. This test is run each time SDM stores or attempts to store information for frontal crash event and also during Turn ON tests.

SDM turns on AIR BAG warning light and sets DTC.

DTC clears when scan tool CLEAR CODES is received by SDM. If, at next ignition ON after receiving CLEAR CODES, SDM detects that data area is full, history DTC B1152 sets. This allows AIR BAG warning light to illuminate should any additional malfunctions be detected.

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  2. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation) . Ensure that all components are properly mounted. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .

SDM contains a sensing device which converts vehicle velocity changes to an electrical signal. Electrical signal is processed by SDM and compared to a value stored in memory. When signal exceeds stored value, additional signal processing is performed and signals are compared to values stored in memory. When 2 signals exceed stored values, SDM causes current to flow through air bag modules, deploying air bags. DTC B1153 sets when a deployment occurs while an inflator circuit fault exists that could result in a non-deployment situation in one or both air bag modules.

DTC sets when SDM detects a frontal crash, up to 30 degrees off centerline of vehicle, of sufficient force to warrant deployment of air bags.

SDM turns on AIR BAG warning light, records CRASH DATA, sets DTC and sends message over class 2 serial data line.

DTC clears when scan tool CLEAR CODES is received.

DTC B1153 will be accompanied by another DTC (other than DTC B1151). Repair malfunction causing other DTCs before diagnosing DTC B1153.

Note. For circuit number and wire color identification, see WIRING DIAGRAMS .

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  2. Turn ignition off. If air bags have deployed, go to step 5). If air bags have not deployed, go to next step.
  3. Inspect front of vehicle and undercarriage for signs of impact. If impact has occurred, go to step 5). If no impact has occurred, go to next step.
  4. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation) . Go to step 6).
  5. Replace components and perform inspections as required following an accident. See «POST-COLLISION INSPECTION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__post-collision-inspection) .
  6. Reconnect all SIR components. Ensure that all components are properly mounted. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .

When the ignition key is turned to RUN position, Instrument Panel Cluster (IPC) sends a message over class 2 serial data line containing serial data keying information. IPC also sends a message over class 2 serial data line containing a partial VIN. SDM receives messages and compares them to information stored in memory.

DTC B1155 sets when either message does not match information stored in SDM. DTC B1155 sets along with DTC 1159 or DTC 1160 depending on the message that does not match. If SDM does not receive the serial data keying message, DTC 1159 will set without DTC B1155. If SDM does not receive a partial VIN message, DTC B1160 will set without DTC B1155. Messages are sent only at POWER-ON.

SDM commands IPC to turn on AIR BAG warning light and sets DTC.

Current DTC B1155 clears when ignition switch is turned OFF. History DTC clears when scan tool CLEAR CODES is received or 250 malfunction free ignition cycles have occurred.

DTC B1155 sets only when wrong message is sent IPC. State Of Health (SOH) DTCs may set in addition to DTCs B1155, B1159 and B1160. SOH DTCs will clear once malfunction is repaired.

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  2. If DTC B1155 is set, go to next step. If not, go to step 9).
  3. If SDM was replaced, go to next step. If not, go to step 5).
  4. Turn ignition off. Install correct SDM. See «SENSING & DIAGNOSTIC MODULE (SDM)»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) under REMOVAL & INSTALLATION. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  5. If IPC was replaced, go to next step. If not, go to step 7).
  6. Turn ignition off. Install correct IPC. If correct IPC is installed, reprogram IPC. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  7. If DTC B1155 and B1159 are both set, go to next step. If not, go to step «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) .
  8. Using scan tool, enter ON BOARD DIAGNOSTICS. Enter IPC OVERRIDE mode. Record OUTPUT OVERRIDE S12 and S13. Information should be: E-, Ksp-, Limo-. Follow scan tool instructions to reprogram IPC to correct information. Go to step 10).
  9. If DTCs B1159, B1160 and B1163 are all set, go to «DTC B1163: LOSS OF SERIAL DATA (NO WARNING LIGHT RESPONSE)»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) . If not, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) .
  10. Reconnect all SIR components. Ensure that all components are properly mounted. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .

When the ignition key is turned to RUN position, Instrument Panel Cluster (IPC) sends a message over class 2 serial data line containing serial data keying information. SDM receives messages and compares information stored in memory.

If SDM does not receive the serial data keying message or message does not match stored information, DTC B1159 will set without DTC B1155. Message is sent only at POWER-ON.

SDM commands IPC to turn on AIR BAG warning light and sets DTC.

Current DTC B1159 clears when SDM receives correct message over class 2 serial data line at POWER-ON. History DTC clears when scan tool CLEAR CODES is received or 250 malfunction free ignition cycles have occurred.

DTC B1159 will set without DTC B1155, when SBM is inoperative. State Of Health (SOH) DTCs may set in addition to DTC B1159.

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  2. Diagnose DTC B1159 using Diagnostic Procedure in «DTC B1155: SDM CALIBRATION MISMATCH»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) . If procedure has been performed, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) .

When the ignition key is turned to RUN position, Instrument Panel Cluster (IPC) sends message over class 2 serial data line containing a partial VIN. SDM receives message and compares information stored in memory.

If SDM does not receive a partial VIN message, DTC B1160 will set without DTC B1155. Message is sent only at POWER-ON.

SDM commands IPC to turn on AIR BAG warning light and sets DTC.

Current DTC B1160 clears when SDM receives correct message over class 2 serial data line at POWER-ON. History DTC clears when scan tool CLEAR CODES is received or 250 malfunction free ignition cycles have occurred.

DTC B1160 will set without DTC B1155, when IPC is inoperative. State Of Health (SOH) DTCs may set in addition to DTC B1160.

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  2. Diagnose DTC B1160 using Diagnostic Procedure in «DTC B1155: SDM CALIBRATION MISMATCH»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) . If procedure has been performed, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) .

When ignition switch is turned to RUN position, IPC flashes AIR BAG warning light 7 times. SDM commands IPC to turn light off if no SIR DTCs are present, by sending message over class 2 serial data line. IPC returns message to SDM that AIR BAG warning light is off.

DTC B1163 sets if SDM receives no response from IPC after sending AIR BAG warning light message 6 times. A loss of State of health (SOH) DTC U1096 or U1255 is also set. Test runs asynchronously during CONTINUOUS MONITORING.

SDM sets DTC B1163 and either DTC U1096 or U1255.

Current DTC clears when ignition switch is turned OFF or SDM receives correct IPC message response over class 2 serial data line. History DTC will clear when scan tool CLEAR CODES is received or 250 malfunction free ignition cycles have occurred.

History DTC B1163 sets if IPC loses voltage or ground with ignition switch in RUN position, or an intermittent short to voltage or ground exists in circuit 1807 class 2 serial data line. SOH DTCs will likely set with DTC B1163 indicating communication is lost between IPC and SDM. Check that IPC is functioning properly.

  1. If SIR DIAGNOSTIC SYSTEM CHECK has been performed, go to next step. If SIR DIAGNOSTIC SYSTEM CHECK has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  2. Turn ignition on. Clear SIR DTCs. Using scan tool, request SIR DTC display. If DTC B1163 is indicated, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) . If DTC B1163 is not indicated, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .

DTC B1171 indicates potential internal SDM malfunction.

DTC sets when any of the following conditions are detected by SDM

1) 23 VLR Voltage out of normal operating range during POWER-ON, POWER-OFF or CONTINUOUS MONITORING tests.

2) Crash data recording reserve voltage discharge time failure for 3 consecutive ignition cycles during POWER-OFF test.

3) Calculated checksum for internal memory does not match stored value during POWER-ON test.

4) Accelerometer is malfunctioning during POWER-ON or CONTINUOUS MONITORING tests.

5) Current source or current sink is malfunctioning during POWER-ON test.

6) Temporary memory storage area is malfunctioning during POWER-ON test.

7) SDM unable to read from or write to EEPROM during POWER-ON test.

8) Inflator arming sensor inside SDM is not closed during deployment event.

9) DTC B1125 has been set during CONTINUOUS MONITORING test.

10) FET driver is malfunctioning during POWER-ON test.

11) Permanent memory storage area is malfunctioning during POWER-ON test.

SDM commands IPC to turn on AIR BAG warning light and sets DTC.

Current DTC clears when no malfunction detected for 500 milliseconds. History DTC clears when scan tool CLEAR CODES is received or 250 malfunction free ignition cycles have occurred.

DTC B1171 indicates a fault within SDM. Replace SDM if DTC B1171 sets, current or history.

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .
  2. If DTC B1125 is indicated, go to «DTC B1125»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system) : DRIVER OR PASSENGER DEPLOYMENT LOOP SHORT TO VOLTAGE. If DTC B1125 is not indicated, go to next step.
  3. Replace SDM. See SENSING & DIAGNOSTIC MODULE (SDM) under «REMOVAL & INSTALLATION»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__removal-installation) . Reconnect all SIR components. Ensure that all components are properly mounted. Go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) .

When ignition switch is turned to RUN position, battery voltage is supplied to SDM through SDM fuse. SDM monitors IGN 1 voltage every 300 milliseconds.

DTC B1327 sets if IGN 1 voltage is less than 9 volts for one second or more and ignition switch is not in START position.

SDM sets DTC.

DTC B1327 clears when IGN 1 voltage is greater than 9.5 volts for one second.

SDM does not check for low IGN 1 voltage, during and for 2 seconds after ignition switch is in START position.

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition on. Connect scan tool to DLC. Using scan tool, select DATA from SDM DATA DISPLAY. If IGN 1 voltage is greater than 9 volts, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If IGN 1 voltage is 9 volts or less, go to next step.
  3. Turn ignition off. Disconnect SDM. (Scheme 15) Turn ignition on. Using Digital Multimeter (J-39200), measure voltage between ground and SDM connector terminal No. 3. (Scheme 1) If voltage is 9 volts or greater, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If voltage is less than 9 volts, check for malfunction in charging system. Repair as necessary.

When ignition switch is turned to RUN position, battery voltage is supplied to SDM through SDM fuse. SDM monitors IGN 1 voltage every 300 milliseconds.

DTC B1328 sets if IGN 1 voltage is greater than 15.5 volts for one second or more.

SDM sets DTC.

DTC B1328 clears when IGN 1 voltage is less than 15 volts for one second.

DTC B1328 may set if vehicle battery is placed on a battery charger, on fast charge, or a long period of time.

  1. If SIR Diagnostic System Check has been performed, go to next step. If SIR Diagnostic System Check has not been performed, go to «SIR DIAGNOSTIC SYSTEM CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check).
  2. Turn ignition on. Connect scan tool to DLC. Using scan tool, select DATA from SDM DATA DISPLAY. If IGN 1 voltage is less than 15.5 volts, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If IGN 1 voltage is 15.5 volts or greater, go to next step.
  3. Turn ignition off. Disconnect SDM. (Scheme 15) Turn ignition on. Using Digital Multimeter (J-39200), measure voltage between ground and SDM connector terminal No. 3. (Scheme 1) If voltage is 15.5 volts or less, go to «SDM INTEGRITY CHECK»(/cadillac/deville-concours/i-final-1999-1999/remont/airbag/#supplemental-inflatable-restraint-system). If voltage is greater than 15.5 volts, check for malfunction in charging system. Repair as necessary.

When the ignition switch is in RUN position, all modules communicating on class 2 serial data line send a State of Health (SOH) message every 2 seconds to ensure that the system is operating properly.

DTC sets when Instrument Panel Cluster (IPC) does not receive a State of Health (SOH) message from the SDM for 5 seconds.

SDM sets DTC U1096.

Current DTC clears when SDM receives a State of Health (SOH) message from the IPC or ignition switch is cycled. History DTC clears when scan tool CLEAR CODES is received.

History DTC B1096 sets if IPC loses voltage or ground with ignition switch in RUN position, or poor connection at IPC caused both serial data lines to open with ignition in RUN position. DTC U1096 will likely set with DTC B1163 when communication is lost between IPC and SDM. Check that IPC is functioning properly.

Modules connected to class 2 serial data line, monitor the line for serial data communications during normal operation. SDM sets DTC U1064 when no SOH messages detected on class 2 data line.

DTC sets when no class 2 messages are detected by SDM and SDM voltage is in normal operating range.

SDM sets DTC.

Current DTC clears when ignition switch is turned OFF or SDM receives message response over class 2 serial data line. History DTC clears when scan tool CLEAR CODES is received.

DTC cannot be retrieved with current status. An intermittent condition is likely to be caused by short to ground on class 2 serial data line.

Modules connected to class 2 serial data line, monitor the line for serial data communications during normal operation. SDM sets DTC U1064 when no SOH messages detected and low voltage detected on class 2 data line for 3 seconds.

DTC sets when no class 2 messages are detected by SDM, SDM voltage is in normal operating range, and low voltage detected on class 2 data line simultaneously.

SDM sets DTC.

Current DTC clears when ignition switch is turned OFF or SDM receives valid Class 2 message. History DTC clears when scan tool CLEAR CODES is received.

DTC cannot be retrieved with current status. An intermittent condition is likely to be caused by short to ground on class 2 serial data line.

Modules connected to class 2 serial data line, monitor the line for serial data communications during normal operation. SDM sets DTC U1064 when no SOH messages detected and high voltage detected on class 2 data line for 3 seconds.

DTC sets when no class 2 messages are detected by SDM, SDM voltage is in normal operating range, and high voltage detected on class 2 data line simultaneously.

SDM sets DTC.

Current DTC clears when ignition switch is turned OFF or SDM receives valid Class 2 message. History DTC clears when scan tool CLEAR CODES is received.

DTC cannot be retrieved with current status. An intermittent condition is likely to be caused by short to ground on class 2 serial data line.

WIRE REPAIR

SIR system requires special wiring repair procedures due to sensitive nature of circuitry. Wire Repair Kit (J-38125-A) contains special sealed splices for use in repairing SIR wiring. Splices use a heat shrink sleeve with sealing adhesive to produce a sealed splice and a cross-hatched core crimp to produce a positive contact for low energy circuits.

Repair damaged SIR wire harness connectors and terminals (except pigtails) using connector repair assembly packs and splice crimping tool provided. Terminals in SIR system are manufactured from a special metal to provide necessary contact integrity for sensitive, low-energy circuits. These terminals are only available in connector repair assembly packs, and no other terminal should be substituted.

If individual terminals on SDM harness connector are damaged, SDM harness connector must be replaced using SDM harness connector pigtail assembly or SDM harness connector replacement kit. If individual terminals on any other SIR connector are damaged, entire connector must be replaced. Use appropriate connector repair assembly pack. Replace entire SIR wire harness, if necessary to maintain SIR circuit integrity.

DO NOT make wiring, connector or terminal repairs on components with wiring pigtails. If a wiring pigtail is damaged, entire component (including pigtail) should be replaced.

Any wiring other than a pigtail can be repaired by splicing in a new section of wire of same gauge. Sealed splices and crimping tool must be used for these splices. Open wire harness by removing tape as necessary, using a sewing seam ripper. Refer to instructions in kit for wiring repair procedure.

TORQUE SPECIFICATIONS

ApplicationFt. Lbs. (N.m)
Steering Wheel Nut30 (41)
INCH Lbs. (N.m)
Driver-Side Air Bag Module Fasteners27 (3)
Front-End Discriminating Sensor Fasteners98 (11)
Passenger-Side Air Bag Module Fasteners18 (2)
Sensing & Diagnostic Module (SDM) Fasteners80 (9)
Side Impact Sensing Module (SISM) Fasteners80 (9)
Side Impact Air Bag Module Fasteners80 (9)
Turn Signal Switch Arm
Round Washer Head Screw27 (3)
Flat Head Tapping Screw22 (2.5)
Turn Signal Switch Assembly Screws31 (3.5)

TORQUE SPECIFICATIONS

SIR System Wiring Diagrams (Deville & Eldorado). Scheme 22

Scheme 22: SIR System Wiring Diagrams (Deville & Eldorado)
Scheme 22: SIR System Wiring Diagrams (Deville & Eldorado)