Двигатели Scania четвёртой серии. Руководство - часть 158

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03:04-06

Fault code D101

Fault

The voltage has been below 0.147 V (under -
1.2 bar absolute pressure), i.e. below the lower 
limit for the fuel pressure to the front bank, 
cylinder 1-3.

Cause

The voltage between pin 3 and 2 in connector 
A1 is too low, or there is a fault with the 
voltage supply to sensor group 2 (pin 8 in 
connector B2, pin 1 in connector A1).

Remarks

If the voltage is outside the permitted range, the 
control unit uses a pre-programmed value 
(0.448 bar absolute pressure).

If the value from the fuel pressure sensor for 
the rear bank, cylinder 4-6 is incorrect at the 
same time, it is probably the shared voltage 
supply for the sensors which is faulty.

Engine torque is limited by approximately 30% 
as long as the fault is active.

Action

Check the signal from the fuel pressure sensor.

Check for any visible faults on the sensor and 
the wiring.

Clean the connectors.

Then, erase the fault code memory and check 
whether the fault code is generated again.

Fault codes

03:04-06

ã

71

Fault code D102

Fault

Internal fault in the control unit.

Cause

The control unit could not process (convert) the 
signal from the fuel pressure sensor on the 
front bank, cylinder 1-3.

Remarks

If the fault is active, the control unit uses a pre-
programmed value (0.448 bar absolute 
pressure).

Engine torque is limited by approximately 30% 
as long as the fault is active.

Action

Clear the fault code memory. Start the engine 
and accelerate the engine to full speed.

If the fault code is regenerated, renew the 
control unit.

Fault codes

72

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03:04-06

Fault code D103

Fault

The fuel pressure to one or two cylinders in the 
front bank, cylinder 1-3, is too high.

Cause

The control unit has discovered that the 
pressure from the solenoid valve to the injector 
does not drop as expected due to an obstruction 
in the fuel supply to the injector.

The fault code can be generated if the vehicle 
has not been driven for some time, especially in 
cold weather, as air might have entered the 
system. The fault code will be generated, either 
when starting or within two minutes after 
starting.

Remarks

As a result, the engine is running unevenly due 
to no fuel supply to one or two cylinder.

Action

Bleed the fuel system and bring the engine to 
operating temperature.

If the engine runs unevenly despite bleeding 
the fuel system and bringing the engine to 
operating temperature, carry out the following:

Change injectors on the front bank, cylinder 
1-3.

Clean the fuel rail (clean the ducts for injection 
timing and fuel with compressed air).

Clean the fuel ducts in the cylinder heads on 
the front bank, cylinder 1-3.

If it becomes evident that the fault is due to 
debris in the fuel system, check the fuel filter 
and change if necessary.

Fault codes

03:04-06

ã

73

Fault code D104

Fault

The fuel pressure to all cylinders in the front 
bank, cylinder 1-3, is too high.

Cause

The fuel volume solenoid valve may be stuck 
open.

The fuel pressure sensor signal is incorrectly 
high in relation to the expectation of the control 
unit considering the current engine load.

Remarks

As a result, the engine speed is limited to 
between 500 and 550 rpm by means of the fuel 
shut-off valve. The engine runs very unevenly.

Action

Check the wiring and clean the connectors to 
the solenoid valves and the pressure sensor on 
the front bank, cylinder 1-3.

Clear the fault code memory. Start the engine 
and accelerate the engine to full speed.

If the fault remains, first renew the fuel volume 
solenoid valve and if necessary the fuel 
pressure sensor.

Fault codes