A maximum of 10 faults can be stored in the MSA 15.2 and MSA 25.3 control module.
After selecting menu point "fault memory", the digits of the fault codes filed in the control module appear together with the relevant text.
Current faults appear in the HHT display highlighted in black.
Stored faults are not highlighted in black in the HHT display.
Procedure in the case of current faults:
Process faults as described in the test program - electrics.
Procedure in the case of stored faults:
Erase fault memory.Start engine and once again read fault memory.
If the fault is again stored, process fault as described in the test program - electrics.
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Faults which exist at one of the components listed below, are indicated by the EDC
(Electronic Diesel Control) indicator lamp coming on.
- Crankshaft position sensor
- Pedal value sensor
- Distributor injection pump
- Electronic shutoff valve (ELAB)
- Control module
The fault memory is not erased if the supply voltage is interrupted, e.g. if the battery is disconnected.
The faults stored can be read at the diagnostic unit with ignition "ON" or with "engine running" using the HHT.
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Fault ambient data
With the HHT, it is additionally possible to display the fault ambient data relating to the fault memory time.
Only the ambient data which were present when the fault first occurred, are stored.
The ambient data are spread over several image pages (up to 8 image pages).
The two last image pages are intended only for the development section.
Image pages with the result / F explain the fault causes e.g.
Short circuit
Open circuit
Value implausible
Formation of substitute value in the event of signal failure
If input signals are not received, the control module forms a substitute value on the basis of other signals in order to maintain the operability of the system.
Formation of the substitute value can result in
- Reduction in output / reduction in maximum engine speed
- Smooth running control being deactivated
- Exhaust gas recirculation being deactivated
- Cruise control being deactivated