DAF LF45, LF55 Series. Manual — part 10

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1-7

UPEC fault codes

UPEC

DAVIE XD diagnostics manual

2

42-8

Unacceptable sine-wave signal of crankshaft
sensor (F552) due to:
-

missing hole in flywheel, for example due to
fouling

-

No noticeable system limitation in UPEC

43-1

Interruption or short circuit/short circuit to supply/
short circuit to earth in the camshaft sensor
(F558) on pin A2 and/or A14 of the ECU

-

Longer start time before engine fires

43-2

Unacceptable sine-wave signal of camshaft
sensor (F558) due to:
-

loose pulse plate

-

Longer start time before engine fires

43-4

Missing or unacceptable sine-wave signal of
camshaft sensor (F558) due to:
-

interruption on pin A2 and/or A14 of the ECU

-

short circuit to earth on pin A2 of the ECU

-

short circuit to supply on pin A2 of the ECU

-

short circuit between pins A2 and A14 of the
ECU

-

Longer start time before engine fires

43-8

Synchronisation signal from camshaft sensor
(F558) faulty or missing under dynamic
conditions due to:
-

contact resistance in connection points of
camshaft sensor

-

faulty camshaft sensor

-

mechanical damage of the pulse plate or
camshaft sensor

-

interruption on pin A14 of the ECU

-

too low a voltage level of camshaft signal

-

Longer start time before engine fires

44-1

Excessive engine speed caused by:
-

downhill driving

-

incorrect changing down into a lower gear

-

No noticeable system limitation in UPEC

45-1

Signal measurement via coolant temperature
sensor (F566) not correct due to:
-

interruption on pin A22 and/or A5 of the ECU

-

Thermometer gives no reading

-

ECU switches to default replacement value
for engine coolant temperature

45-2

Signal measurement via coolant temperature
sensor (F566) not correct due to:
-

short circuit to earth on pin A22 of the ECU

-

short circuit between pins A22 and A5 of the
ECU

-

Thermometer gives no reading

-

ECU switches to default replacement value
for engine coolant temperature

45-4

No signal measurement via coolant temperature
sensor (F566) due to:
-

internal ECU fault

-

Thermometer gives no reading

-

ECU switches to default replacement value
for coolant temperature

46-1

Boost pressure signal measurement via inlet air
boost pressure/temperature sensor (F649) not
correct due to:
-

short circuit to supply on pin A12 and/or A23
of the ECU

-

Reduced engine output

-

ECU switches to default replacement value
for boost pressure

46-2

Boost pressure signal measurement via inlet air
boost pressure/temperature sensor (F649) not
correct due to:
-

interruption on pin A23 and/or A12 of the
ECU

-

short circuit to earth on pin A23 and/or A12
of the ECU

-

Reduced engine output

-

ECU switches to default replacement value
for boost pressure

Fault code

Fault code description with possible cause

Symptom

UPEC

1-8

©

UPEC fault codes

2

DAVIE XD diagnostics manual

46-4

No boost pressure signal measurement via inlet
air boost pressure/temperature sensor (F649)
due to:
-

internal ECU fault

-

Reduced engine output

-

ECU switches to default replacement value
for boost pressure

47-1

Inlet air temperature signal measurement via inlet
air boost pressure/temperature sensor (F649) not
correct due to:
-

interruption on pin A21 and/or A17 of the
ECU

-

ECU switches to default replacement value
for inlet air temperature

47-2

Inlet air temperature signal measurement via inlet
air boost pressure/temperature sensor (F649) not
correct due to:
-

short circuit to earth on pin A21 of the ECU

-

short circuit between pins A21 and A17 of
the ECU

-

ECU switches to default replacement value
for inlet air temperature

47-4

No inlet air temperature signal measurement via
inlet air boost pressure/temperature sensor
(F649) due to:
-

internal ECU fault

-

ECU switches to default replacement value
for inlet air temperature

48-1

Signal measurement via fuel temperature sensor
(F565) not correct due to:
-

interruption on pin A6 and/or A11 of the ECU

-

ECU switches to default replacement value
for fuel temperature

48-2

Signal measurement via fuel temperature sensor
(F565) not correct due to:
-

short circuit to earth on pin A11 of the ECU

-

short circuit between pins A11 and A6 of the
ECU

-

ECU switches to default replacement value
for fuel temperature

48-4

No fuel temperature signal measurement via fuel
temperature sensor (F565) due to:
-

internal ECU fault

-

ECU switches to default replacement value
for fuel temperature

51-1

Signal measurement on potentiometer in
accelerator pedal sensor (F672) not correct due
to:
-

short circuit to supply on pin B23 of the ECU

-

interruption on pin B35 of the ECU

-

short circuit between pin B16 and pin B23 of
the ECU

-

moisture in connector connection

-

Indistinct response to accelerator pedal

-

Engine runs at increased idling speed

51-2

Signal measurement on potentiometer in
accelerator pedal sensor (F672) not correct due
to:
-

interruption on pin B16 and/or pin B23 of the
ECU

-

short circuit to earth on pin B16 and/or pin
B23 of the ECU

-

short circuit between pin B16 and pin B35 of
the ECU

-

short circuit between pin B23 and pin B35 of
the ECU

-

moisture in connector connection

-

Indistinct response to accelerator pedal

-

Engine runs at increased idling speed

51-4

No signal measurement on potentiometer in
accelerator pedal sensor (F672) due to:
-

internal ECU fault

-

Indistinct response to accelerator pedal

-

Engine runs at increased idling speed

Fault code

Fault code description with possible cause

Symptom

©

1-9

UPEC fault codes

UPEC

DAVIE XD diagnostics manual

2

51-8

Conflict between position of idling switch and
output signal of potentiometer in accelerator
pedal sensor (F672) due to:
-

short circuit to supply on pin B16 of the ECU

-

short circuit between pin B17 and pin B25 of
the ECU

-

short circuit to earth on pin B17 of the ECU

-

moisture in connector connection

-

No response to accelerator pedal

-

Engine runs at increased idling speed

Conflict between position of idling switch and
output signal of potentiometer in accelerator
pedal sensor (F672) due to:
-

interruption on pin B17 and/or pin B25 of the
ECU

-

When the accelerator pedal is depressed
the idling speed of the engine increases
gradually.

52-8

After the ignition had been switched on, the brake
pedal was operated several times (20x) while the
accelerator pedal was still being operated

-

No noticeable system limitation

53-1

Short circuit to supply of vehicle speed signal of
MTCO (B525) on pin B29 of the ECU

-

Cruise control cannot be activated

-

Variable vehicle speed limitation function
cannot be activated

-

Engine brake can be activated with the
vehicle stationary

-

Control function for engine speed control
cannot be activated

53-2

Short circuit to earth of vehicle speed signal of
MTCO (B525) on pin B29 of the ECU

-

Cruise control cannot be activated

-

Variable vehicle speed limitation function
cannot be activated

-

Engine brake can be activated with the
vehicle stationary

-

Control function for engine speed control
cannot be activated

53-8

Unacceptable vehicle speed signal of MTCO
(B525) on pin B29 of the ECU due to:
-

interruption on pin B29

-

excessive vehicle speed for example due to
incorrectly programmed K factor in MTCO

-

loose pulse ring in gearbox

-

Cruise control cannot be activated

-

Variable vehicle speed limitation function
cannot be activated

-

Engine brake can be activated with the
vehicle stationary

-

Control function for engine speed control
cannot be activated

54-1

Too high a voltage on the atmospheric pressure
sensor in the ECU due to:
-

internal fault in ECU

-

No noticeable system limitation in UPEC

54-2

Too low a voltage on the atmospheric pressure
sensor in the ECU due to:
-

internal fault in ECU

-

No noticeable system limitation in UPEC

54-4

Internal ECU fault relating to the atmospheric
pressure sensor

-

No noticeable system limitation in UPEC

55-8

Frequency of speed signal of electronically
controlled fan clutch (B335) on pin B30 of the
ECU is too high due to:
-

mechanically blocked fan clutch

-

No noticeable system limitation in UPEC

Fault code

Fault code description with possible cause

Symptom

UPEC

1-10

©

UPEC fault codes

2

DAVIE XD diagnostics manual

55-9

Unacceptable frequency of speed signal of
electronically controlled fan clutch (B335) on pin
B30 of the ECU in relation to engine speed due
to:
-

interruption on pin B30

-

short circuit to supply or to earth on pin B30

-

fan leakage

-

no supply voltage

-

Reduced engine power (coolant
temperature may increase excessively as a
result of which the coolant overheating
safety may be activated)

56-1

Irregular engine running detected by the ECU due
to:
-

fuel leak of injector pipe of cylinder 1

-

defective/clogged injector of cylinder 1

-

air in fuel system

-

internal leakage of pump unit of cylinder 1

-

clogged injector pipe of cylinder 1

-

too low a combustion pressure in cylinder 1
caused by a mechanical defect of the engine
(valve seal etc.)

-

Irregular engine running and reduced
engine power

56-2

Irregular engine running detected by the ECU due
to:
-

fuel leak of injector pipe of cylinder 5

-

defective/clogged injector of cylinder 5

-

air in fuel system

-

internal leakage of pump unit of cylinder 5

-

clogged injector pipe of cylinder 5

-

too low a combustion pressure in cylinder 5
caused by a mechanical defect of the engine
(valve seal etc.)

-

Irregular engine running and reduced
engine power

56-3

Irregular engine running detected by the ECU due
to:
-

fuel leak of injector pipes of cylinders 1 and 5

-

defective/clogged injectors of cylinders 1
and 5

-

air in fuel system

-

internal leakage of pump units of cylinders 1
and 5

-

clogged injector pipes of cylinders 1 and 5

-

too low a combustion pressure in cylinders 1
and 5 caused by a mechanical defect of the
engine (valve seal etc.)

-

Irregular engine running and reduced
engine power

56-4

Irregular engine running detected by the ECU due
to:
-

fuel leak of injector pipe of cylinder 3

-

defective/clogged injector of cylinder 3

-

air in fuel system

-

internal leakage of pump unit of cylinder 3

-

clogged injector pipe of cylinder 3

-

too low a combustion pressure in cylinder 3
caused by a mechanical defect of the engine
(valve seal etc.)

-

Irregular engine running and reduced
engine power

Fault code

Fault code description with possible cause

Symptom