DAF LF45, LF55 Series. Manual — part 18

©

1-11

AS Tronic fault codes

AS TRONIC

DAVIE XD diagnostics manual

3

3114

Clutch closes unexpectedly during standstill and
with engaged gear. Current clutch position
changes without the solenoid valves of the clutch
unit being actuated. The clutch unit travel sensor
transmits clutch movements to the modulator.
-

Poor freedom of movement of clutch plate
on the keyways of the input shaft

-

During controlled closing of the clutch, the
clutch remains temporarily open due to
insufficient mechanical freedom of
movement of the clutch (heavy point)

-

Mechanical fault of clutch unit solenoid
valves

At standstill:
-

gearbox is automatically shifted to the
neutral position

-

once the neutral position has been reached,
it will be possible to drive on after the
selector switch has been changed from
position D-N-D

-

automatic mode not available

3117

It is not possible to teach-in the clutch during the
self-test. No change in clutch position is detected,
despite actuation of solenoid valves Y14 to Y17 in
the clutch unit. Possible cause:
-

internal modulator fault (D954)

-

internal clutch unit fault (B385)

-

electrical fault in wiring harness between
modulator and clutch unit

-

incorrect clutch travel sensor signal, engine
speed signal or input shaft speed signal

-

System is not available

3118

Clutch does not open despite the fact that
solenoid valves Y16 and Y17 are actuated:
-

internal modulator fault (D954)

-

internal clutch unit fault (B385)

-

electrical fault in wiring harness between
modulator and clutch unit

-

incorrect clutch travel sensor signal, engine
speed signal or input shaft speed signal

When driving:
-

no more gear changes possible

-

automatic mode not available

At standstill:
-

if the vehicle comes to a halt, a new effort is
made to open the clutch

-

at standstill the gearbox is automatically
shifted to the neutral position

-

system is not available

3119

Clutch does not close despite the fact that
solenoid valves Y14 and Y15 are actuated. The
clutch cannot transmit any engine torque.
-

Clutch travel sensor does not recognise the
closing motion of the clutch when driving or
when the engine is idling

-

Input shaft speed is not equal to the engine
speed

-

Admissible solenoid valve switch-on time is
exceeded

When driving:
-

no more gear changes possible

-

automatic mode not available

At standstill:
-

if the vehicle comes to a halt, the clutch is
opened

-

at standstill the gearbox is automatically
shifted to the neutral position

-

system is not available

3120

Selector valve Y17 (slowly open clutch) is not
working despite actuation (3x):
-

mechanical fault of selector valve Y17

-

Function is taken over by redundant selector
valve Y16

-

Reduced shifting comfort

-

Automatic mode not available

3121

Selector valve Y16 (open clutch rapidly) is not
working despite actuation (3x):
-

mechanical fault of selector valve Y16

-

Function is taken over by redundant selector
valve Y17

-

Reduced shifting comfort

-

Automatic mode not available

3122

Selector valve Y15 (close clutch slowly) is not
working despite actuation (3x):
-

mechanical fault of selector valve Y15

-

Function is taken over by redundant selector
valve Y14

-

Reduced shifting comfort

-

Automatic mode not available

Fault code

Fault code description with possible cause

Symptom

AS TRONIC

1-12

©

AS Tronic fault codes

3

DAVIE XD diagnostics manual

3123

Selector valve Y14 (close clutch rapidly) is not
working despite actuation (3x):
-

mechanical fault of selector valve Y14

-

Function is taken over by redundant selector
valve Y15

-

Reduced shifting comfort

-

Automatic mode not available

3124

Incorrect clutch travel sensor signal due to:
-

clutch travel sensor signal being outside
ranch

-

increasing input shaft speed during
standstill, with the clutch sensor detecting an
opened clutch

-

unacceptable difference between engine
speed and input shaft speed, with clutch
being open

When driving:
-

clutch is opened and closed in a time-
controlled fashion

-

automatic mode not available

At standstill:
-

shunting is not possible

-

if driving off from a stationary position does
not take place within a certain period of time,
the gearbox will be automatically shifted to
the neutral position. The drive-off gear must
then be selected manually.

-

reduced clutch comfort when closing the
clutch as you drive off

3126

Incorrect pressure sensor signal from integrated
pressure sensor in the modulator (D954) due to:
-

defective pressure sensor in modulator

-

pressure sensor signal outside range

-

defective modulator (D954)

-

System available, provided there is sufficient
air supply to the modulator

-

Teaching in of position sensors of selector
valves and clutch position during the self-
test takes more time than usually

-

Automatic mode not available

3127

Incorrect ECU temperature signal from integrated
temperature sensor in the modulator (D954) due
to:
-

defective temperature sensor in modulator

-

temperature sensor signal outside range

-

defective modulator (D954)

-

No noticeable system limitation

-

Automatic mode not available

3129

Position sensor signal, main range, in the
modulator (D954):
-

short circuit to earth

-

short circuit to supply

-

interruption

When driving:
-

if the fault occurs during shifting, the signal
"gear engaged" from the main range
position sensor will be generated in a time-
controlled fashion

-

no more gear changes possible, except from
neutral position

-

automatic mode not available

At standstill:
-

the possibility to shift to the neutral position
is monitored by testing the engaging cylinder
for gate selection by actuating selector
valves Y4 and Y5

-

driving off from a stationary position is
possible

-

to prevent tooth-to-tooth contact, the air
supply main valve Y10 and main range
selector valves Y6/Y7 remain engaged until
the clutch position during closing exceeds a
particular value

Fault code

Fault code description with possible cause

Symptom

©

1-13

AS Tronic fault codes

AS TRONIC

DAVIE XD diagnostics manual

3

3132

Teach-in fault, main range position sensor, during
self-test:
-

main range position sensor signal outside
range

-

if there is insufficient air pressure and the air
pressure sensor is not defective, an effort is
made to shift the main range to the neutral
position

-

internal modulator fault (D954); selector
valves Y6/Y7 are not actuated correctly

-

mechanically defective gearbox

-

With ignition off, the gearbox is shifted to the
neutral position

-

With ignition on, the selector valves Y6/Y7
(main range) and Y10 (air supply) are
actuated. As a result the gearbox must be
shifted to the neutral position. This takes
place 3 times.

-

Mechanical neutral position is measured by
the main range position sensor. If this signal
is out of range and there is sufficient air
pressure (air pressure sensor in modulator),
a teach-in fault is stored.

-

System not available

3133

Position sensor signal, gate selection in the
modulator (D954):
-

short circuit to earth

-

short circuit to supply

-

interruption

When driving:
-

only the gears opposite to the reverse gear
can be shifted

-

automatic mode not available

At standstill:
-

only the drive-off gears opposite to the
reverse gear can be shifted

-

reverse gear not available

3136

Teach-in fault, gate selection position sensor,
during self-test:
-

if sufficient air pressure is available, the gate
selection sensor signal is out of range after
3 failed efforts to select another gate
position

-

if insufficient air pressure is available, the
gate selection sensor signal is out of range
after a certain waiting time and a new effort

-

internal modulator fault (D954); selector
valves Y4/Y5 are not actuated correctly

-

mechanically defective gearbox

-

In case of an electrical fault in selector
valves Y4/Y5 for gate selection the ECU
tries to engage the forward gears of the main
range: 12AS - 2

nd

/3

rd

gear of main range;

16AS - 3

rd

/4

th

gear of main range

-

If the forward gears cannot be engaged, the
ECU will try to engage the reverse gear gate
of the main range: 12AS - R/1

st

gear of main

range; 16AS - 1

st

/2

nd

gear of main range

-

If it is possible to teach-in a gate, only the
gears in that particular gate can be shifted

-

If this is not possible, the system is not
available

-

Automatic mode not available

3137

Position sensor signal, rear-mounted range box
in the modulator (D954):
-

short circuit to earth

-

short circuit to supply

-

interruption

When driving:
-

only gears in the high or low range can be
shifted

-

no shifting up/down is possible when driving

-

if the fault occurs when shifting up/down, the
gears will be shifted in a time-controlled and
delayed fashion

-

Automatic mode not available

At standstill:
-

all drive-off gears can be engaged

-

main valve Y10 and rear-mounted range box
valve Y8 or Y9 remain actuated until the
clutch has reached a certain position. This
prevents tooth-to-tooth contact of the rear-
mounted range box

Fault code

Fault code description with possible cause

Symptom

AS TRONIC

1-14

©

AS Tronic fault codes

3

DAVIE XD diagnostics manual

3140

Teach-in fault, rear-mounted range box position
sensor, during self-test:
-

if there is sufficient air pressure, the sensor
signal of the rear-mounted range box is out
of range

-

internal modulator fault (D954); selector
valve Y8 or Y9 is not actuated correctly

-

mechanically defective gearbox

-

With ignition off, the gearbox remains in the
last selected range

-

Through actuation of main valve Y10 and
selector valve Y8 or Y9 for the rear-mounted
range box, the position of the engaged
range is ensured once again

-

If it is only possible to teach-in the low range,
gears can only be shifted in this range

-

If it is only possible to teach-in the high
range, gears can only be shifted in this
range

-

If it is impossible to teach-in either the low or
the high range, no more gears can be shifted

-

System is not available

3141

Position sensor signal, splitter range in the
modulator (D954):
-

short circuit to earth

-

short circuit to supply

-

interruption

-

It is not possible to shift gears in the splitter
range

-

Driving is only possible in the last selected
position of the splitter range: K1 or K2. If we
assume that K2 is the last selected position,
the PTO function will not be available

-

If the selected gear cannot be engaged, the
next higher gear is engaged, if possible

-

If the fault occurs when shifting the splitter
range, this range will be shifted in a time-
controlled and delayed fashion

-

Automatic mode not available

3144

Teach-in fault, splitter range position sensor,
during self-test:
-

if there is sufficient air pressure, the sensor
signal of the splitter range is out of range

-

internal modulator fault (D954); selector
valve Y2 or Y3 is not actuated correctly

-

mechanically defective gearbox

-

With ignition off, the gearbox remains in the
last selected range

-

Through actuation of main valve Y10 and
selector valve Y2 or Y3 for the splitter range,
the position of the engaged range is ensured
once again

-

If it is only possible to teach-in the low range,
only low-range gears can be engaged

-

If it is only possible to teach-in the high
range, only high-range gears can be
engaged

-

If it is impossible to teach-in either the low or
the high range, no more gears can be shifted

-

System is not available

3145

Rear-mounted range box does not disengage
from the last selected position after actuation:
-

insufficient air pressure available

-

internal modulator fault (D954); selector
valves Y8/Y9 are not actuated correctly

-

mechanically defective gearbox

When driving:
-

when shifting from the low to the high range,
the highest gear of the low range is engaged

-

when shifting from the high to the low range,
the lowest gear of the high range is engaged

-

automatic mode not available

At standstill:
-

if it is impossible to shift the low range, the
lowest gear in the high range is selected as
drive-off gear

-

no reverse shifting possible in the high range

Fault code

Fault code description with possible cause

Symptom