Malfunctions, MID 128
Group 30: Electrical system
MID 128, PID 97 Water switch, fuel filter MID 128: Engine control unit Fault code FMI 0: The value is valid but exceeds the normal working range. FMI 9: Abnormal updating rate. FMI
Fault code explanation
0
Water in fuel
9
Faulty sensor / Faulty sensor circuit
Fault indication Warning is displayed in the tachometer/display. FMI 0: Indication for “water in fuel” flashes in the alarm display. FMI 9: An orange lamp flashes in the alarm display.
Symptom Engine stops when there is a short circuit in the monitor power supply cables.
Connector (36 pin)
Circuit description The monitor consists of a measurement probe containing two measurement points, galvanically isolated by a layer of insulation. The measurement probe is in contact with the fuel. When there is no water in the fuel, the resistance between the measurement points is very high. If there is any water in the fuel, the resistance falls. At a threshold resistance (water has been detected), the monitor (pin 1) will give an output signal which is proportional to the monitor supply voltage. Pin 16 on the engine control unit (EDC7) provides pin 2 on the monitor with battery voltage. Pin 3 on the monitor is connected to battery negative via pin 3 on the engine control unit.
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