Vehicle Electrical System, General Repair Notes

Vehicle Electrical System, General Repair Notes

CAUTION:
- When disconnecting and connecting battery, the procedure must be followed as described in the Repair information.
- Always refer to and heed CAUTION. and WARNING. texts associated with repair and/or removal and installation information.
- Only the yellow repair cables and insulation tape supplied with VAS 1978 are to be used for wiring/connector repairs. The use of yellow repair wires and yellow insulation tape identifies that a repair has taken place VAS 1978 Instruction Manual.
- Before beginning wiring and connector repairs, determine and rectify the cause of damage, e.g.: pinched between metal parts, malfunctioning electrical consumers, corrosion due to water ingress etc.
- Avoid loosening or removing any individual Ground (GND) connections (potential for corrosion).
- When repairs are completed, always perform a functional check of the component or system. Where applicable, check and erase Diagnostic Trouble Codes (DTCs) and set basic settings where applicable according to Repair information and/or VAS 5051/5052.
- Some tools are supplied with a tool safety clip, which is slid over the tool points after using the tool, in order to protect other workers from injuries and tool points from damage.

- Observe the current information in the corresponding Repair Instructions for all repairs.
- Observe country-specific laws.
- Before working on electrical system, disconnect battery Ground (GND) strap.
- By disconnecting battery Ground (GND) strap (current disruption), safe work on the electrical system is guaranteed. It is necessary to disconnect battery positive wire only when removing the battery.
- Further information, e.g. installing and removing individual components, can be found in the appropriate Repair information.
- For repairs to vehicle electrical system, soldering is not permitted.
- Only perform wiring harness and connector repairs to vehicle electrical system using Wiring Harness Repair Kit VAS1978 or Wiring Harness Repair Set VAS1978A.
- Wiring harness repairs may only be carried out using yellow wires.
- Wiring harness repairs may not be performed again in the wrapping of the vehicle specific wiring harness and are to be marked with yellow adhesive tape.
- These yellow wires and every location on wiring harness wrapped in yellow insulating tape indicates a previous repair.
- Crimp connections must never be repaired. If necessary, lay a wire parallel to the faulty wire.
- After crimping, heat-shrink crimp connections using hot air gun to prevent moisture penetration.
- Always observe also the supplementary notes for repairing wiring harnesses on airbag- and seat belt tensioner systems, fiber optic cables, CAN-Bus wires, antenna wires and wire cross-sections up to 0.35 sq.mm.
- Perform a function test after every repair. If necessary, check DTC memory, erase and/or bring systems into basic setting.
- If possible, do not loosen Ground (GND) straps from body (danger of corrosion).