Air Bag Restraint System — Audi A6 C5 (1997-2001)

DESCRIPTION & OPERATION

WARNING

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

The air bag restraint system is designed to provide increased accident protection for driver and passengers by deploying front air bags and front and rear seat belt tensioners in a front-end collision and side air bags when side impact is detected. The system is designed to be used with 3-point safety belts.

Main components of the system include driver-side air bag module, passenger-side air bag module, driver and passenger seat-mounted side air bag modules, left and right rear seat-mounted side air bag modules, front and rear seat belt tensioners, air bag control module, side air bag crash sensors, rear seat belt indicators, data link connector, spiral spring assembly (under steering wheel, in steering column) and air bag indicator light. (Scheme 1)

Air bag control module is capable of system self-diagnostics. Air bag system components are monitored electrically and any interferences in operation can be detected. These interferences (faults) are then stored in air bag control module memory. Air bag control module memory differentiates between types of faults. After diagnosis and servicing, fault memory can be erased.

Scheme 1

SERVICING

Manufacturer recommends replacing main air bag system components (air bag modules, seat belt tensioners, spiral spring and control module) every 15 years. Replacement year and month appear on a sticker located on driver-side B-pillar. Sticker must be updated when components are replaced.

SERVICE PRECAUTIONS

Observe these precautions when working with air bag systems

Never use test light, ohmmeter or voltmeter to test air bag system, except when testing spiral spring. System can only be tested using Scan Tool (VAG1551) and Adapter (VAG1551/3). DO NOT use Air Bag Tester (VAG1619).
Air bag system components must never be opened, disassembled or repaired. Always use new parts.
Air bag system components have expiration dates listed on driver-side B-pillar. Upon expiration (15 years), components must be replaced. Air bag modules must not be stored for longer than 3 months.
DO NOT use air bag system components that have been dropped from heights of approximately 20" or higher. Always replace air bag components that have been mechanically damaged.
Disable air bag system before servicing any part of system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__disabling-activating-air-bag-system) .
Before disconnecting battery cable(s) and disabling air bag system, obtain radio security code from vehicle owner.
After servicing, check system for proper operation. See «SYSTEM OPERATION CHECK»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__system-operation-check) .
DO NOT leave undeployed air bag system components unattended. Install components in vehicle immediately after removing from packaging.
When placing undeployed air bag modules on a bench or other surface, always make certain that trim cover faces up.
DO NOT allow chemical cleaners, oil, or grease to contact vinyl covering on air bag modules.
DO NOT expose air bag modules to temperatures greater than 212°F (100°C).
Use only original equipment seat covers that are designed for use with side air bags (identified by label on fabric).

CENTERING SPIRAL SPRING

If spiral spring is twisted, it must be centered before installation. From central position, spiral spring must be able to turn approximately 3 1/2 turns in both directions.

DISABLING & ACTIVATING AIR BAG SYSTEM

Before proceeding, see «SERVICE PRECAUTIONS»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__service-precautions) . To disable air bag system, disconnect and shield negative battery cable.
To activate system, ensure no one is in vehicle. Reconnect negative battery cable. Perform system operation check to ensure system is functioning properly. See «SYSTEM OPERATION CHECK»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__system-operation-check) .

DEPLOYED AIR BAGS OR SEAT BELT TENSIONER

Deployed air bag modules and seat belt tensioners can be disposed of like any other part. Handle air bag module using gloves, and wear safety glasses. Control modules contain a mercury switch and must be disposed of as hazardous material.

UNDEPLOYED AIR BAGS OR SEAT BELT TENSIONER

Undeployed air bags and seat belt tensioners must be removed from vehicle and deployed before disposal. Undeployed air bag modules and seat belt tensioners must not be disposed of at normal refuse locations. Undeployed air bag modules and seat belt tensioners contain substances which can cause illness or injury if handled improperly. Disposal of air bag modules and seat belt tensioners in any manner inconsistent with proper procedures may be a violation of federal, state and/or local laws.

Transportation of undeployed air bag modules and seat belt tensioners is subject to laws for flammable solids and regulated by Department of Transportation (DOT) and most state governments. Special shipping procedures are required. A DOT exemption label must be attached to undeployed air bag module or seat belt tensioner being shipped. This DOT exemption label is included with replacement air bag module or seat belt tensioner. Use replacement air bag module or seat belt tensioner shipping box to return undeployed component. Repair shops should check with hazardous material section of their respective state governments for applicable shipping requirements.

SCRAPPED VEHICLE

Undeployed air bags and seat belt tensioners must be removed from vehicle and deployed before scrapping vehicle. Undeployed air bag modules and seat belt tensioners must not be disposed of at normal refuse locations.

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

WARNING

Failure 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

Before proceeding, see «SERVICE PRECAUTIONS»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__disabling-activating-air-bag-system). Control module is located behind front center console. (Scheme 1)
Remove rear air outlet and rear air duct connecting piece. (Scheme 2) If necessary, remove center armrest. Remove rear console mounting nut. Remove mat lining and bolts. Remove shift lever knob and protective boot, if equipped with manual transmission. Unclip and remove center console insert upwards. Remove bolts and parking brake lever trim.
Raise rear center console at front and disconnect harness connector. Pull parking brake handle fully up. Disconnect trim from retaining tab on parking brake lever. Lift rear section of console over stud and move toward rear. Lift rear section of console and remove forward over parking brake lever.
Open front ashtray and unclip trim section. Remove radio and A/C control head. Remove front ashtray and switch trim panel. (Scheme 3) Remove front console mounting bolts. Pry out trim cap and remove nut. Pull center console over mounting pin on driver-side. Remove console toward rear. Remove connecting pieces for left and right-rear footwell vent air ducts. Release retainer and disconnect control module connector. Remove control module mounting nuts. Remove control module. (Scheme 4)

Installation

To install, reverse removal procedure. Tighten control module mounting nuts to 53 INCH lbs. (6 N.m). Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Replacement control modules must be coded. See ON BOARD DIAGNOSTIC (OBD) SYSTEM under DIAGNOSIS & TESTING. Check system for proper operation. See SYSTEM OPERATION CHECK .

Scheme 2

Scheme 2: Installation

Scheme 3

Scheme 4

Removal (Driver-Side)

Before proceeding, see «SERVICE PRECAUTIONS»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__disabling-activating-air-bag-system). Driver-side air bag module is located on steering wheel hub.
Use Torx T30 socket to release locking lugs on back of steering wheel. (Scheme 5) Tilt air bag module down and disconnect air bag module harness connectors. Remove air bag module from vehicle.

To install, reverse removal procedure. Install air bag module and secure with locking lugs. Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check system for proper operation. See SYSTEM OPERATION CHECK .

Removal (Passenger-Side)

Before proceeding, see «SERVICE PRECAUTIONS»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__disabling-activating-air-bag-system). Passenger-side air bag module is located above glove box.
Remove glove box. Disconnect air bag module connector. (Scheme 6) Remove nuts and air bag module.

To install, reverse removal procedure. Tighten air bag module mounting nuts to 80 INCH lbs. (9 N.m). Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check system for proper operation. See SYSTEM OPERATION CHECK .

Removal (Side)

Before proceeding, see «SERVICE PRECAUTIONS»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__disabling-activating-air-bag-system). Side air bag modules are mounted in outside seat back padding of each front seat.
Remove side air bag mounting screws. (Scheme 7) Carefully unclip side air bag from retaining hooks. Disconnect harness connector. Remove air bag module.

To install, reverse removal procedure. Drill out holes to 5.5 mm. Use new air bag mounting screws provided with new air bag. Tighten screws to 48 INCH lbs. (5.5 N.m). Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check system for proper operation. See SYSTEM OPERATION CHECK .

Scheme 5

Scheme 5: Installation

Scheme 6

Scheme 7

Crash sensors for side air bag modules are mounted under front seats. (Scheme 8) Remove seat and lower A-pillar trim. Unclip sill panel trim on inside. Lift floor mat and disconnect crash sensor harness connector. Remove bolts and crash sensor.

To install, reverse removal procedure. Tighten crash sensor mounting bolts to 53 INCH lbs. (6 N.m). Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check system for proper operation. See SYSTEM OPERATION CHECK .

Scheme 8

Scheme 8: Installation

Before proceeding, see SERVICE PRECAUTIONS . Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Turn front wheels to straight-ahead position. Remove driver-side air bag module. See AIR BAG MODULES . Remove steering wheel bolt. Disconnect harness connectors. Remove steering wheel.

To install, reverse removal procedure. Install new steering wheel bolt and tighten to 44 ft. lbs. (60 N.m). Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check system for proper operation. See SYSTEM OPERATION CHECK .

Before proceeding, see «SERVICE PRECAUTIONS»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__service-precautions). Disable air bag system. See «DISABLING & ACTIVATING AIR BAG SYSTEM»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system__disabling-activating-air-bag-system). Ensure front wheels are in straight-ahead position. Spiral spring is located under steering wheel.
Remove driver-side air bag module. See «AIR BAG MODULES»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system). Remove steering wheel. See «STEERING WHEEL»(/audi/a6/c5-1997-2001/remont/airbag/#air-bag-restraint-system). Remove screws and tilt lever handle. Remove screws and upper steering column cover. (Scheme 5) Remove screws and lower steering column cover. Disconnect harness connector. Release locking lugs and remove spiral spring. DO NOT turn or twist spiral spring after removal.

To install, reverse removal procedure. Ensure front wheels are in straight-ahead position. Center spiral spring if necessary. See CENTERING SPIRAL SPRING under ADJUSTMENTS. Tighten steering column cover screws to 5 INCH lbs. (0.6 N.m), and tilt lever handle screws to 25 INCH lbs. (2.8 N.m). Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check system for proper operation. See SYSTEM OPERATION CHECK .

Removal (Front)

Before proceeding, see SERVICE PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Remove sill panel trim and lower seat belt anchor bolt. (Scheme 9) Remove upper and lower B-pillar trim. Remove shouldered nut to disconnect upper belt from B-pillar. Disconnect seat belt tensioner harness connector. Remove bolt and seat belt tensioner.

To install, reverse removal procedure. Tighten seat belt mounting fasteners and tensioner mounting bolt to 37 ft. lbs. (50 N.m). Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check system for proper operation. See SYSTEM OPERATION CHECK .

Removal (Side-Rear)

Before proceeding, see SERVICE PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Remove rear seat back. Remove lower seat belt anchor bolt. (Scheme 10) Remove belt guide and belt webbing guide covers. Remove rear shelf and backrest. Pull belt through belt webbing guide. Disconnect harness connector at seat belt tensioner. Open luggage compartment side trim cover. Remove bolt and seat belt tensioner.

To install, reverse removal procedure. Tighten seat belt anchor bolt and tensioner mounting bolt to 37 ft. lbs. (50 N.m). Activate air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM . Check system for proper operation. See SYSTEM OPERATION CHECK .

Removal (Center-Rear)

Before proceeding, see SERVICE PRECAUTIONS. Disable air bag system. See DISABLING & ACTIVATING AIR BAG SYSTEM. Remove rear seat bench. Remove lower seat belt anchor bolt. (Scheme 11)and (Scheme 12). Remover belt guide trim. If equipped with folding backrest, remove belt adjuster trim by prying on both sides at lug. Remove rear shelf and backrest. Disconnect harness connector at seat belt tensioner. If equipped with folding backrest, open luggage compartment side trim cover to access tensioner. Remove bolt and seat belt tensioner.

Scheme 9

Scheme 9: Installation

Scheme 10

Scheme 11

Scheme 12

SYSTEM OPERATION CHECK

Turn ignition switch to ON position. Air bag Malfunction Indicator Light (MIL) should come on for about 10 seconds and then go out. If MIL comes on and remains on, control module has detected a system fault. See DIAGNOSIS & TESTING . If light does not glow, check bulb. If bulb is okay, perform diagnostics. See DIAGNOSIS & TESTING .

DIAGNOSIS & TESTING

WARNING

Failure 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 .

ON BOARD DIAGNOSTIC (OBD) SYSTEM

Air bag system is equipped with On Board Diagnostic (OBD) capability. If malfunction exists in a monitored sensor or other component, a Diagnostic Trouble Code (DTC) indicating type of malfunction is stored in DTC memory. Air bag Malfunction Indicator Light (MIL) in instrument cluster illuminates. DTCs remain stored in memory and MIL remains on until DTC memory is checked and erased using Scan Tool (VAG1551). If air bag system has deployed, DTC memory records whether components deployed correctly.

Connecting Scan Tool (VAG1551)

Connect Scan Tool (VAG1551) with Adapter (VAG1551/3) to 16-pin Data Link Connector (DLC) in lower left corner of instrument panel, to left of steering wheel. (Scheme 13) If there is no display, check voltage supply to DLC.

Scheme 13

Scheme 13: Connecting Scan Tool (VAG1551)

Checking & Erasing DTC Memory

With Scan Tool (VAG1551) connected, turn ignition ON. Press button "1" to select rapid data transfer. Press buttons "1" and "5" to select air bag code 15. Confirm input with "Q" button. Use right arrow to scroll forward through program. After approximately 5 seconds, RAPID DATA TRANSFER and SELECT FUNCTION will appear on display. Press buttons "0" and "2" to select "Check DTC Memory" function 02. Confirm input with "Q" button. Perform appropriate diagnostic test. See DIAGNOSTIC TROUBLE CODES for diagnosis of indicated codes. Press buttons "0" and "5" to select "Erase DTC Memory" function 05. Confirm input with "Q" button. Intermittent malfunctions are indicated by "/SP" on right side of scan tool display. Press "Print" button for complete printout of scan tool operation. To conduct an automatic test sequence, enter "00" and confirm input with "Q" button.

Coding Control Module

00004: Vehicles with front air bags, front seat belt tensioners and 2 rear seat belt tensioners.
00006: Vehicles with front air bags, front seat belt tensioners and 3 rear seat belt tensioners.
00104: Vehicles with front air bags, front side air bags, front seat belt tensioners and 2 rear seat belt tensioners.
00106: Vehicles with front air bags, front side air bags, front seat belt tensioners and 3 rear seat belt tensioners.
00204: Vehicles with front air bags, front side air bags, rear side air bags, front seat belt tensioners and 2 rear seat belt tensioners.
00206: Vehicles with front air bags, front side air bags, rear side air bags, front seat belt tensioners and 3 rear seat belt tensioners.
00205: Vehicles with front air bags, front side air bags, rear side air bags, front seat belt tensioners, 2 rear seat belt tensioners and seat belt fastened sensor.
00207: Vehicles with front air bags, front side air bags, rear side air bags, front seat belt tensioners, 3 rear seat belt tensioners and seat belt fastened sensor.
00115: Vehicles with front air bags, front side air bags, front seat belt tensioners, 2 rear seat belt tensioners, belt inquiry and front seat occupant sensor.
00117: Vehicles with front air bags, front side air bags, front seat belt tensioners, 2 rear seat belt tensioners, belt inquiry and front seat occupant sensor.

Confirm input with "Q" button. Press buttons "0" and "6" to select "End Output" function 06. Confirm input with "Q" button. Remove key from ignition. Repeat procedure to ensure correct coding. Check system for proper operation. See SYSTEM OPERATION CHECK .

DIAGNOSTIC TROUBLE CODES

Note. The following is a list of all malfunctions recognized by air bag control module.

Possible Cause

Battery discharged or malfunctioning. Short in wiring.

Corrective Action

Charge or replace battery. Repair short in wiring.

Open circuit in wiring. Spiral spring defective. Driver-side air bag defective. Control module defective.

Locate and repair open circuit. Check spiral spring. Replace driver-side air bag. Replace control module.

Short circuit in wiring. Spiral spring defective. Driver-side air bag defective. Control module defective.

Locate and repair short circuit. Check spiral spring. Replace driver-side air bag. Replace control module.

Open circuit in wiring. Passenger-side air bag defective. Control module defective.

Locate and repair open circuit. Replace passenger-side air bag. Replace control module.

Short circuit in wiring. Passenger-side air bag defective. Control module defective.

Locate and repair short circuit. Replace passenger-side air bag. Replace control module.

Air bag circuit wiring damaged or control module defective.

Locate and repair damaged wiring. Replace control module.

Air bag circuit wiring damaged. Spiral spring defective. Air bag module defective. Control module defective.

Locate and repair damaged wiring. Check spiral spring. Replace air bag module(s). Replace control module.

Air bag circuit wiring damaged or control module defective.

Locate and repair damaged wiring. Replace control module.

Air bag circuit wiring damaged. Spiral spring defective. Air bag module defective. Control module defective.

Locate and repair damaged wiring. Check spiral spring. Replace air bag module(s). Replace control module.

Frontal or side collision.

Replace air bags, control module and other components as necessary.

Open circuit in wiring. Driver-side seat belt tensioner disconnected or defective. Control module defective.

Locate and repair open circuit. Connect harness connector. Replace control module.

Short circuit in wiring. Driver-side seat belt tensioner defective. Control module defective.

Locate and repair short circuit. Replace control module.

Seat belt tensioner circuit wiring damaged or control module defective.

Locate and repair damaged wiring. Replace control module.

Seat belt tensioner circuit wiring damaged. Seat belt tensioner defective. Control module defective.

Locate and repair damaged wiring. Replace seat belt tensioner. Replace control module.

Open circuit in wiring. Passenger-side seat belt tensioner disconnected or defective. Control module defective.

Locate and repair open circuit. Connect harness connector. Replace control module.

Short circuit in wiring. Passenger-side seat belt tensioner defective. Control module defective.

Locate and repair short circuit. Replace control module.

Seat belt tensioner circuit wiring damaged or control module defective.

Locate and repair damaged wiring. Replace control module.

Seat belt tensioner circuit wiring damaged. Seat belt tensioner defective. Control module defective.

Locate and repair damaged wiring. Replace seat belt tensioner. Replace control module.

Control module incorrectly coded for vehicle configuration.

Code control module appropriately.

Wiring damaged. Tensioner defective. Control module defective.

Locate and repair open circuit. Replace tensioner. Replace control module.

Wiring damaged. Tensioner defective. Control module defective.

Locate and repair short circuit. Replace tensioner. Replace control module.

Wiring damaged or control module defective.

Locate and repair damaged wiring. Replace control module.

Wiring damaged. Tensioner defective. Control module defective.

Locate and repair damaged wiring. Replace tensioner. Replace control module.