| General notes on the injection system |
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| The engine control unit is equipped with a self-diagnosis system. The first step, before commencing repairs or fault finding, is to interrogate the fault memories of all the control units using the automatic test sequence. This is necessary because different control units are interconnected via data bus. Also check the vacuum hoses and connections (unmetered air). |
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| Fuel hoses in the engine compartment must be secured with spring band clamps. The use of clamp-type or screw-type clips is not allowed. |
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| Switch off the ignition before disconnecting and connecting the battery, as this may damage the 4AV control unit. |
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| Components marked with an * are checked by the self-diagnosis unit → Chapter. |
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| Components marked with ** can be tested with the final control diagnosis → Chapter. |
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| A minimum voltage of 11.5 V is required for perfect functioning of the electrical components. |
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| Do not use sealants containing silicone. Traces of silicone elements drawn in by the engine are not burnt in the engine and damage the lambda probes. |
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| If after fault finding, repair or inspection of components the engine starts briefly and then stops, it is possible that the immobiliser blocks the engine control unit. Then interrogate the fault memory and if necessary adapt the control unit → Chapter. |
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| Certain inspections may cause the control unit to detect and store a fault. It is therefore necessary to interrogate the fault memory after having completed all inspections and repairs, and if necessary delete → Chapter. |
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| Vehicles fitted with airbags are equipped with a crash fuel shut-off. It is intended to reduce the risk of a vehicle fire after a crash as the fuel pump is disconnected by the fuel pump relay. This installation also enhances the starting behaviour of the engine. When opening the door the fuel pump is activated for 2 seconds in order to build up the pressure in the fuel system. |
| Testing the intake system for tightness (unmetered air) → Chapter. |
| Testing the engine operating conditions → Chapter. |
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