DAF LF45, LF55 Series. Manual — part 9

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1-3

UPEC fault codes

UPEC

DAVIE XD diagnostics manual

2

31-2

Short circuit to earth or interruption in the pump
unit (B131) on pin A35 of the ECU, causing the
pump unit of cylinder 1 to be switched off

-

Engine running on 5 cylinders

-

Reduced engine output

Short circuit to earth on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Short circuit to supply of the pump unit (B131) on
pin A35 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Interruption in the pump unit (B131) on pin A24 of
the ECU, causing the pump unit of cylinders 1, 2
and 3 to be switched off

-

Engine running on 3 cylinders

-

Engine does not supply power

31-4

The valve inside the pump unit (B131) does not
close due to:
-

jammed valve

-

internal contamination

-

internal wear

-

Engine running on 5 cylinders

-

Reduced engine output

The valve inside the pump unit (B131) does not
close fast enough due to:
-

internal contamination

-

internal wear

-

Reduced engine output

31-8

The valve inside the pump unit (B131) does not
open fast enough due to:
-

mechanical problems

-

internal contamination

-

No noticeable system limitation in UPEC

32-1

Short circuit to supply on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

32-2

Short circuit to earth or interruption in the pump
unit (B135) on pin A26 of the ECU, causing the
pump unit of cylinder 5 to be switched off

-

Engine running on 5 cylinders

-

Reduced engine output

Short circuit to earth on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Short circuit to supply of the pump unit (B135) on
pin A26 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Interruption in the pump unit (B135) on pin A25 of
the ECU, causing the pump unit of cylinders 4, 5
and 6 to be switched off

-

Engine running on 3 cylinders

-

Engine does not supply power

32-4

The valve inside the pump unit (B135) does not
close due to:
-

jammed valve

-

internal contamination

-

internal wear

-

Engine running on 5 cylinders

-

Reduced engine output

The valve inside the pump unit (B135) does not
close fast enough due to:
-

internal contamination

-

internal wear

-

Reduced engine output

32-8

The valve inside the pump unit (B135) does not
open fast enough due to:
-

mechanical problems

-

internal contamination

-

No noticeable system limitation in UPEC

Fault code

Fault code description with possible cause

Symptom

UPEC

1-4

©

UPEC fault codes

2

DAVIE XD diagnostics manual

33-1

Short circuit to supply on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

33-2

Short circuit to earth or interruption in the pump
unit (B133) on pin A34 of the ECU, causing the
pump unit of cylinder 3 to be switched off

-

Engine running on 5 cylinders

-

Reduced engine output

Short circuit to earth on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Short circuit to supply of the pump unit (B133) on
pin A34 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Interruption in the pump unit (B133) on pin A24 of
the ECU, causing the pump unit of cylinders 1, 2
and 3 to be switched off

-

Engine running on 3 cylinders

-

Engine does not supply power

33-4

The valve inside the pump unit (B133) does not
close due to:
-

jammed valve

-

internal contamination

-

internal wear

-

Engine running on 5 cylinders

-

Reduced engine output

The valve inside the pump unit (B133) does not
close fast enough due to:
-

internal contamination

-

internal wear

-

Reduced engine output

33-8

The valve inside the pump unit (B133) does not
open fast enough due to:
-

mechanical problems

-

internal contamination

-

No noticeable system limitation in UPEC

34-1

Short circuit to supply on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

34-2

Short circuit to earth or interruption in the pump
unit (B136) on pin A27 of the ECU, causing the
pump unit of cylinder 6 to be switched off

-

Engine running on 5 cylinders

-

Reduced engine output

Short circuit to earth on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Short circuit to supply of the pump unit (B136) on
pin A27 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Interruption in the pump unit (B136) on pin A25 of
the ECU, causing the pump unit of cylinders 4, 5
and 6 to be switched off

-

Engine running on 3 cylinders

-

Engine does not supply power

34-4

The valve inside the pump unit (B136) does not
close due to:
-

jammed valve

-

internal contamination

-

internal wear

-

Engine running on 5 cylinders

-

Reduced engine output

The valve inside the pump unit (B136) does not
close fast enough due to:
-

internal contamination

-

internal wear

-

Reduced engine output

Fault code

Fault code description with possible cause

Symptom

©

1-5

UPEC fault codes

UPEC

DAVIE XD diagnostics manual

2

34-8

The valve inside the pump unit (B136) does not
open fast enough due to:
-

mechanical problems

-

internal contamination

-

No noticeable system limitation in UPEC

35-1

Short circuit to supply on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

35-2

Short circuit to earth or interruption in the pump
unit (B132) on pin A33 of the ECU, causing the
pump unit of cylinder 2 to be switched off

-

Engine running on 5 cylinders

-

Reduced engine output

Short circuit to earth on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Short circuit to supply of the pump unit (B132) on
pin A33 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Interruption in the pump unit (B132) on pin A24 of
the ECU, causing the pump unit of cylinders 1, 2
and 3 to be switched off

-

Engine running on 3 cylinders

-

Engine does not supply power

35-4

The valve inside the pump unit (B132) does not
close due to:
-

jammed valve

-

internal contamination

-

internal wear

-

Engine running on 5 cylinders

-

Reduced engine output

The valve inside the pump unit (B132) does not
close fast enough due to:
-

internal contamination

-

internal wear

-

Reduced engine output

35-8

The valve inside the pump unit (B132) does not
open fast enough due to:
-

mechanical problems

-

internal contamination

-

No noticeable system limitation in UPEC

36-1

Short circuit to supply on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

36-2

Short circuit to earth or interruption in the pump
unit (B134) on pin A28 of the ECU, causing the
pump unit of cylinder 4 to be switched off

-

Engine running on 5 cylinders

-

Reduced engine output

Short circuit to earth on pump unit connections,
pin A24 and/or pin A25 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Short circuit to supply of the pump unit (B134) on
pin A28 of the ECU

-

Engine stalls and/or engine starts but does
not fire

Interruption in the pump unit (B134) on pin A25 of
the ECU, causing the pump unit of cylinders 4, 5
and 6 to be switched off

-

Engine running on 3 cylinders

-

Engine does not supply power

36-4

The valve inside the pump unit (B134) does not
close due to:
-

jammed valve

-

internal contamination

-

internal wear

-

Engine running on 5 cylinders

-

Reduced engine output

The valve inside the pump unit (B134) does not
close fast enough due to:
-

internal contamination

-

internal wear

-

Reduced engine output

Fault code

Fault code description with possible cause

Symptom

UPEC

1-6

©

UPEC fault codes

2

DAVIE XD diagnostics manual

36-8

The valve inside the pump unit (B134) does not
open fast enough due to:
-

mechanical problems

-

internal contamination

-

No noticeable system limitation

41-1

Voltage level of crankshaft sensor (F552) sine-
wave signal on pins A1 and A13 of the ECU is too
low due to:
-

too large an air gap between flywheel and
crankshaft sensor

-

contact resistance in connection points

-

short circuit or interruption

-

No engine speed signal on pin B5 of the
ECU

Excessive oscillation of crankshaft sensor (F552)
sine-wave signal on pin A1 of the ECU due to:
-

irregularity in flywheel circumference

-

faulty fitting of the flywheel

-

No noticeable system limitation in UPEC

41-2

Too low a voltage level of camshaft sensor (F558)
sine-wave signal on pins A2 and A14 of the ECU
due to:
-

too large an air gap between pulse disc and
camshaft sensor

-

contact resistance in connection points

-

short circuit or interruption

-

Longer start time before engine fires

Excessive oscillation of camshaft sensor (F558)
sine-wave signal on pins A2 and A14 of the ECU
due to:
-

irregularity in pulse disc circumference

-

faulty fitting of the pulse disc

-

Longer start time before engine fires

41-8

Incorrect or unacceptable sine-wave signals of
both the crankshaft sensor (F552) and camshaft
sensor (F558) due to:
-

contact resistance in connection points

-

defective ECU

-

interruption or short circuit in crankshaft
sensor and camshaft sensor

-

Engine stalls and/or engine starts but does
not fire

42-1

Signal of crankshaft sensor (F552) on pins A1 en
A13 of ECU fails due to:
-

poor connection/bad contact

-

faulty sensor

-

No engine speed signal on pin B5

42-2

Synchronisation of crankshaft sensor signal and
camshaft sensor signals is not correct due to:
-

loose pulse disc

-

incorrect timing setting

-

signal disturbance caused by external
influences

-

Engine starts but will not fire

42-4

Missing or unacceptable sine-wave signal of
crankshaft sensor (F552) due to:
-

interruption on pin A1 and/or A13 of the ECU

-

short circuit to earth on pin A1 of the ECU

-

short circuit to supply on pin A1 of the ECU

-

short circuit between pins A1 and A13 of the
ECU

-

No engine speed signal on pin B5 of the
ECU

Fault code

Fault code description with possible cause

Symptom