Self-diagnosis of the injection system

The fuel injection system control unit is equipped with a fault memory. which records malfunctions of sensors or systems, indicating the type of malfunction. Sometimes there are malfunctions that are random in nature (sporadic). Such faults are additionally indicated by the symbol «S/P». If a sporadic fault has not occurred after 50 engine starts, it is automatically cleared (removed) from memory. If malfunctions affecting the vehicle control systems are detected, the warning light comes on. Faults can be read using the VAG 1551 fault code reader or VAG 1552 tester. After the fault has been eliminated, it must be deleted from the fault memory.

The fault memory is divided into permanent and temporary (fault cleared after 50 engine starts).

The selection of functions using the VAG 1551 fault code reader or the VAG 1552 tester is shown in Table 4.4.

Table. 4.4. Function selection using the VAG 1551 fault code reader or VAG 1552 tester