IFI Diagnosis/Fault Memory

Notes re fault memory
- Fault memory: fault readout
current faults: are displayed with a grey background grid
stored faults: are displayed with a light background

All inputs/outputs are checked for plausibility during operation. Any fault which exists is stored in the fault memory of the IFI control module.
The faults remain stored with ignition "OFF" or after disconnecting the car battery.

In the case of major faults, the EPC (Electronic Power Control) malfunction indicator lamp (A1e43) comes on.

(USA) version
In the case of exhaust-relevant faults the CHECK ENGINE malfunction indicator lamp (A1e26) comes on and the following readout appears on the multifunction display:
CHECK-ENGINE
ENGINE ELECTRONICS.
The faults are identified with an OBD fault code.
Such faults are e.g.:
- Crankshaft position sensor (L5/6)
- Fuel rack position sensor (Y23/1I1)
- IFI accelerator position sensor (R25/2)
- IFI fuel metering control (Y23/1)
- EGR lift sensor (B28/3)
- EGR vacuum transducer(Y31/1)
- Pressure regulating flap vacuum transducer (Y31/2)

Fault ambient data
With the HHT it is additionally possible to display the fault ambient data which existed at the time the fault was stored. Only those ambient data which existed when the fault first occurred, are stored. The ambient data are distributed over several image pages (up to 8 image pages), the last two image pages being intended solely for Development.
Image pages with the result V/F explain the causes of the fault e.g.:
- voltage too high
- voltage too low
- signal too large
- signal too small
- value implausible