Volkswagen Workshop Service and Repair Manuals

• ◆ The engine control unit is equipped with self-diagnosis. Before carrying out repairs and fault finding the fault memory of all control units must be interrogated using the automatic test sequence (in Guided fault finding). This is necessary as the various control units are interconnected via a data bus. Also the vacuum hoses and connections must be checked (unmetered air).
• ◆ Fuel hoses in engine compartment must only be secured with spring-type clips. The use of clamp or screw-type clips is not permitted.
• ◆ The battery may only be disconnected when the ignition is switched off. If a coded radio is installed, obtain radio code before disconnecting battery.
• ◆ For trouble-free operation of the electrical components, a voltage of at least 11.5 V is necessary.
• ◆ Do not use sealing compounds containing silicone. Particles of silicone drawn into the engine, will not be burnt in the engine and damage the Lambda probe.

• ◆ If the engine starts, runs for a short period and then stops, after fault finding, repairs or component tests, then the fault may lie with the immobilizer which is blocking the engine control unit. In such cases the control unit must be adapted ; Adapting components.
• ◆ During some checks it is possible that the control unit will detect and store a fault. Therefore after completing all checks and repairs the fault memory must be interrogated and if necessary erased. => page 24-46, Interrogating and erasing fault memory.
• ◆ Models with an airbag are fitted with a crash fuel shut-off system. It reduces the danger of a fire in a crash in that the fuel pump is switched off via the fuel pump relay.
• ◆ When the door is opened the fuel pump is activated for 2 seconds to build up pressure in fuel system. This improves the starting characteristics of the engine.

Safety precautions .

Rules for cleanliness => Page 24-23.

Technical data => Page 24-28.