Volvo TAD734GE Repair Manual

Group 30: Electrical system Diagnostic Trouble Codes
43
splice
water in
fuel
MID 128, PID 97
Water in fuel
MID 128: Engine control unit
FMI 0: The sensor value is valid but above the nor-
mal working range.
FMI 3: The voltage exceeds the normal value or is
short circuited to higher voltage.
FMI 4: The voltage is less than the normal value or
is short circuited to lower voltage.
FMI Fault code explanation
0 Water in fuel
3, 4 Faulty sensor / Faulty monitor circuit
Fault indication
DCU: Engine warning in DCU display
CIU: Flash code
Flash code
Electrical fault: 2.9
Value fault: 2.1
Symptom
None
Circuit description
A monitor is located in the water trap under the fuel fil-
ter. Its task is to detect whether there is water in the
fuel.
The monitor senses the resistance between two pins,
wich are in contact with the fuel. When there is no wa-
ter in the fuel, the resistance is very high. If there is
any water in the fuel, the resistance falls.
At a threshold resistance (water has been detected),
the monitor’s output signal (yellow cable) to the engine
control unit pin B8 will be pulled down to zero.

Volvo TAD734GE Specifications

General

Engine Model	TAD734GE
Cooling System	Liquid-cooled
Displacement	7.15 liters
Bore x Stroke	108 x 130 mm
Aspiration	Turbocharged
Fuel System	Electronic Unit Injectors (EUI)
Engine Speed	1500 rpm
Emission Level	EU Stage II
Engine Type	4-stroke, 6-cylinder in-line diesel engine