In addition, in order to accurately determine the defect in the event of a malfunction of the electronic engine control, it is necessary to conduct a series of tests in a certain sequence. With an unqualified approach, damage to electronic units cannot be ruled out, and these damages entail expensive repairs. The control device cannot even be checked by the means at the disposal of a car enthusiast, let alone repaired. Practice shows that malfunctions of these units are very rare, however, sometimes malfunctions of sensors, switches or wires may occur, the causes of such malfunctions can be determined independently.
Before repairs or troubleshooting, it is necessary to interrogate the fault recorder, which is part of the engine control unit. This is done using the VAS 5051 diagnostic system (in the workshop). Self-diagnosis makes the search easier.
All vacuum hoses and connections must be checked for air leaks.
Fuel hoses in the engine compartment may only be secured using strap clamps. The use of clamps with a bolt and nut or hose clamps is not permitted.
The battery can only be disconnected and connected when the ignition is off, otherwise the control device may malfunction.
For the electrical components to function properly, a voltage of at least 11.5 volts is required.
Do not use sealants containing silicone. Particles of silicone components do not burn in the engine, as a result they damage the oxygen sensor.
During some tests, the control device may recognize and register some malfunction, therefore after the tests it is recommended to interrogate and, if necessary, erase the data of the malfunction recorder.