Mid 128, Pid 94; Fuel Pressure - Volvo TAD650VE Workshop Manual

Group 30: Electrical system
splice
splice
engine
interface
Note! Only TAD 650, 660, 750, 760 has an engine interface. On
TAD 734 the wiring to the EMS 2 is the same but without any en-
gine interface.

MID 128, PID 94

Fuel pressure

MID 128: Engine control unit
FMI 1:
FMI 3:
FMI 5:
FMI 7:
FMI
1
3, 5
7
Fault indication
DCU:
CIU:
Flash code
Electrical fault: 3.6
Value fault:
Symptom
None
Circuit description
The sensor is an active sensor, i.e. the sensor must
receive operating voltage. Pin B17 on the engine con-
trol unit provides pin 1 on the sensor with an operating
fuel pres-
voltage of +5 Volt. Pin 4 on the sensor is connected to
sure
battery negative via pin B18 on the engine control unit.
The output signal from the pressure sensor, pin 2 on
the sensor to pin B16 on the EMS 2, is a voltage sig-
nal that is proportional to the fuel pressure.
Diagnostic Trouble Codes
The sensor value is valid but below the nor-
mal working range.
The voltage exceeds the normal value or is
short circuited to higher voltage.
The current is less than the normal value or
is open circuited.
Mechanical fault. The system responds in-
correctly.
Fault code explanation
Fuel pressure is too low
Faulty sensor / Faulty sensor circuit
Fuel pressure is critically low
Engine warning in DCU display.
Flash code
3.8
37