Airbag - Wiring Harness Repair
Group: 97Number: 00-01
Date: Dec. 4, 2000
Subject:
Airbag Wiring Harness Repairs Using Repair Kit VAS 1978 and VAS 1978/AR
Model(s):
All 2000
Service
This bulletin contains repair procedures applicable to airbags. Certain wiring harness terminals and connectors may now be repaired using VAS 1978 Wire Harness Repair kit and VAS 1978/AR supplemental kit.
The following contain important information to keep in mind while using the VAS 1978 kit and VAS 1978/AR supplemental kit to perform harness repairs. For more detailed questions about special cases, or the latest information about critical repairs involving safety Systems, contact the Audi Technician Helpline at 1-800-388-2384.
WARNING!
When working on ANY airbag system, ALWAYS read and follow the Repair Manual CAUTIONS & WARNINGS.
WARNING!
DO NOT repair wiring and connectors that are hard wired to any airbag system component. Only the wiring and connectors that are a part at the main vehicle harness may be repaired. Shielded wiring for components, such as speed sensors or knock sensors, may not be repaired, but must ALWAYS be replaced.
DO NOT use solder when repairing a wiring harness.
Only use approved methods and materials it wiring harness repairs are required.
For additional information, refer to:
^ Self Study Program, "Wiring Harness Inspection and Repair", Course Number 971003
^ Instruction Manual, Wiring Harness Repair kit VAS 1978
^ Service Circular, Tools & Equipment, No: ATE-00-03, dated Apr. 3, 2000
For airbag repairs or component replacement, see Repair Manual, Body Interior, Repair Group 69.
Note:
If a quality repair cannot be achieved due to severe harness damage, replace the harness. Severe harness damage includes the following conditions:
^ Stretched harness with damage to wire insulation
^ Chafing in multiple locations
^ Wiring that reveals corrosion
EVERY repair adds some resistance. When carrying out repairs, make as few repairs as possible, using only the proper tools and components.
The VAS 1978 and VAS 1978/AH kits meet the requirements for the latest Audi wiring diagram repair procedures. Replacement tools, terminals and other harness repair components are available separately.
Wire Harness Repair Kit VAS 1978
The VAS 1978 and VAS 1978/AR Wiring Harness Repair kits feature an organized assortment of tools and color-coded components that support all authorized wiring harness repairs. Perform repairs using only the tools, wires, terminals and other components supplied in the VAS 1978 Wiring Harness Repair kit and VAS 1978/AR supplemental kit.
The kits include detailed instructions for disconnecting, unlocking, disassembling and repairing different types of multi-point connectors currently in use in Audi vehicles.
Wire Harness Repair Kit VAS 1978/AR
The instruction manual that accompanies the VAS 1978 kit is an excellent guide for how to use the kit.
General Notes
^ The quality of crimped termination in wiring harnesses is critical. Always use the proper tools and components.
^ Repair wires and connectors must match in size.
^ DO NOT use soldering to repair wiring harnesses in Audi vehicles.
^ Perform all repairs using ONLY the VAS 1978 Wiring Harness Repair kit and VAS 1978/AR supplemental kit.
^ ALL parts of the harness must be completely rebuilt and restored to ORIGINAL condition.
^ The repaired harness must be mounted and routed EXACTLY as it was before the repair.
^ Check for special surface treatment on connector terminals. If, for example, the original terminal was gold-plated, a gold-plated replacement must be used.
^ For questions about specific applications, refer to Repair Manual repair procedures, Technical Bulletins, or consultants on the Audi Technician Helpline.
^ Inspection of several features can be used to assess the quality of a crimped termination. Refer to Self Study Program, Course Number 971003, "Wiring Harness Inspection and Repair'; Page 24, "Crimped Terminals, visual Checks" for more information.
Terminals
Terminals are the electrical contacts located either in a connector or at the mating connection to an electrical or electronic device. The only function of a terminal is to conduct electricity as efficiently as possible.
The terminal design, material, surface protection and method of attachment (termination) all depend on the cost, reliability and durability requirements of the application.
Terminal inspection
Replace terminal when one of following conditions occur:
^ Terminal is bent or unintentionally deformed
^ Terminal is cracked or torn at crimped areas (B and C)
^ Wire insulation has been drawn into core crimp (B)
^ Material is cracked at transition bend (D)
^ Terminal coating shows signs of moisture or "greasy" coating. The terminal surface should be bright and shiny.
Primary lock tab(s) (A) should be straight and stand away from terminal.
Note:
During terminal extraction, primary lock tab(s) may have been pressed into terminal. To straighten lock tabs, carefully lift tab using a sharp edge.
Crimping
Crimping means using force to compress and mechanically deform (crimp) the terminal around the uninsulated strands of wire or cable. Compressing the terminal and wire accomplishes the two following important results:
^ Forces contaminants out of the crimp area, achieving more direct contact and better conductivity
^ Causes terminal and wire strands to flow, filling the space between strands. This significantly increases the contact area and conductivity
The ideal amount of compression or crimping force (the degree of deformation) is a balance of mechanical strength and electrical conductivity:
^ Too little crimping force results in greater resistance (reduced conductivity) and less strength - the wire may pull out
^ Too much crimping force results in greater potential for wire fatigue, and breakage
The ideal result is achieved when the crimped terminal and the wire inside are compressed by approximately 20% for both open and closed barrel terminals.
For crimping to work effectively, the wire and terminal must be matched in size. This ensures that both the terminal and wire will be compressed during crimping, resulting in a good connection.
Open-barrel terminals
An open-barrel terminal has crimping wings that are folded over in order to compress the wire during crimping.
^ When folded in sequence, they form an overlapping crimp.
^ When folded simultaneously, they form a "B" crimp, as shown.
Closed-barrel terminals
Closed-barrel terminals have a round oval shaped crimp area. Crimping deforms the barrel using, for example, a nest and indent die, as shown.
Wire and Insulation Condition
The end of the wire, which is crimped to a terminal and carries the seal, must be free of damage and distortion.
- Inspect for unevenness in the outer insulation that may prevent a proper seal, especially where a cable tie or other fastener has been used to secure the harness.
If the wire has been installed too tightly and the insulation has been damaged
- Make the repair in a different location, where the wire is not damaged.
Wire harness, repair
Note:
DO NOT use other procedures or matedals, other than those in VAS 1978, for wire harness repairs, specifically soldering, wire nuts, generic repair kits, etc.
Always review Safety Precautions in VAS 1978 Instruction Manual prior to performing any wiring harness repairs.
If wiring harness repairs are required:
- Use only VAS 1978 Wire Harness Repair kit and VAS 1978/AR Airbag Wire Harness Repair Kit.
If the wire harness cannot be repaired using this procedure and materials contained in VAS 1978 and VAS 1978/AR:
- Replace the wire harness.