Group 30: Electrical system
Diagnostic Trouble Codes
59
Circuit description
The sensor is an active sensor, i.e. the sensor must
receive operating voltage. The boost pressure sensor
measures the absolute pressure, which is the sum of
the boost pressure and atmospheric pressure (300
kPa thus corresponds to a boost pressure of 200 kPa
when atmospheric pressure is 100 kPa).
Pin A7 on the engine control unit (EMS 2) provides pin
3 on the sensor with an operating voltage of +5 Volt.
Pin 1 on the sensor is connected to battery negative
via pin A11 on the EMS 2. The output signal from the
pressure sensor, pin 4 on the sensor to pin A22 on the
EMS 2, is a voltage signal that is proportional to the
boost pressure.
Fault tracing
FMI 0 Boost pressure is too high
Conditions for fault code:
Boost pressure exceeds the set value of the engine
protection parameter.
Possible reason:
•
The wastegate does not function properly.
•
Faulty boost pressure sensor.
•
Wrong turbo compressor unit according to the en-
gine specification.
Suitable action:
1.
Check wastegate functionality (see workshop
manual Group 21-26).
2.
Check function of boost pressure sensor by con-
trol measuring boost pressure using a measuring
tap (see workshop manual Group 21-26).
3.
Check that turbo compressor unit is in according
to the engine specification.
splice
boost air and
temperature
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.
