1. Check connecting wires and plug connections between AFC control unit and instrument cluster for good contact and breaks.
2. The sensor signal (duration of injection) can be checked with an oscilloscope on the central electric plug L, term. 5, or on the instrument cluster (center multiple-pin plug, term. 11). The square wave signal changes frequency when the engine speed changes.
3. If the instrument cluster receives the sensor signal, check the printed circuit and, if necessary, replace the instrument.
4. If there is excessive deviation in the upper range between displayed and actual consumption, check the speedometer signals on left multiple-pin plug term. 2 by turning the driven wheels.
5. If the fuel consumption indicator does not return to zero after switching off the ignition, check whether center multiple-pin plug term. 14 of instrument cluster has + 12 volts (check fuse no. 23).
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