| Properties of the self-diagnosis |
Note | The self-diagnosis monitors only a part of the injection and ignition system. The “Current Flow Diagrams, Fault Finding and Fitting Locations” binder should always be used for fault finding. |
| The engine control unit -J537- is equipped with a fault memory. |
| If malfunctions occur in the monitored sensors or components, they are stored in the fault memory with indication of the fault type. |
| After the engine control unit has analysed the information, it distinguishes between the different fault codes ⇒ fault table → Chapter or → Chapter and stores these faults until the fault memory is erased. |
| Faults that only occur temporarily (sporadically) are output with the suffix “sporadically occurred fault”. On the display these faults are indicated by the suffix “SP”. Possible causes of sporadic faults are e.g. a loose contact or a momentary line interruption. If a sporadic fault no longer occurs within 40 warming-up phases (engine started at a temperature of 50°C and switched off at more than 72 °C), the fault is then automatically erased fom the fault memory. |
| The stored faults can be read out with the vehicle system tester -V.A.G 1552- using programme card -6.0- and higher version or fault reader -V.A.G 1551- using programme card -9.0- and higher version or vehicle diagnosis, measurement and information system -VAS 5051-. |
| After the fault or faults have been rectified, it is necessary to erase the fault memory → Chapter and also to re-generate the readiness code → Chapter. |
Note | General information on self-diagnosis is provided in the operating instructions for the diagnostic devices -V.A.G 1551-, -V.A.G 1552- or -VAS 5051-. |
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