DAF LF45, LF55 Series. Manual - part 41

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Airtronic (ACH-EA) fault codes

AIRTRONIC (ACH-EA)

DAVIE XD diagnostics manual 

9

1. AIRTRONIC (ACH-EA) FAULT CODES

1.1 INTRODUCTION

If the electronic unit detects a system fault, this 

fault is usually stored in the memory of the 

electronic unit as a fault code.

Most system faults will also generate a warning.

AIRTRONIC (ACH-EA)

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Airtronic (ACH-EA) fault codes

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DAVIE XD diagnostics manual

1.2 EXPLANATORY NOTES TO AIRTRONIC D2/D4 (ACH-EA) FAULT CODES

Fault code

Fault code description with possible cause

Symptom

0-0

Internal fault in ECU (D871) due to:
-

defective ECU (D871)

-

insufficient battery voltage

-

Cab heater does not start or fails during 
operation

0-1

Internal fault in ECU (D871) due to:
-

defective internal temperature sensor in 
ECU (D871)

-

Cab heater does not start or fails during 
operation

1-0

Fault when starting ACH-EA, no flame is detected 
within the start time due to:
-

no or insufficient supply of fuel

-

insufficient supply of inlet air

-

clogged exhaust

-

defective flame sensor (combisensor F691)

-

defective glow filament (B168)

-

Cab heater does not start or fails during 
operation

1-4

Too many failed start attempts
(activation cut-off)

-

Cab heater does not start. The cab heater 
shuts down after a maximum of 255 failed 
starts and the electronic unit will block.

-

Electronic unit released by erasing faults 
using DAVIE XD

2-0

Flame extinguishes repeatedly during operation 
due to:
-

no or insufficient supply of fuel

-

insufficient supply of inlet air

-

clogged exhaust

-

defective flame sensor (combisensor F691)

-

Cab heater fails or emits smoke and 
supplies insufficient heat

3-1

Voltage (>30 V for at least 20 seconds) on pin 1 
of the ECU (D871) is too high due to:
-

excessive alternator/battery voltage

-

Cab heater fails during operation

3-2

Voltage (<20 V for at least 20 seconds) on pin 1 
of the ECU (D871) is too low due to:
-

insufficient alternator/battery voltage

-

interruption on pin 1 of the ECU (D871)

-

Cab heater fails during operation

4-0

Flame signalling when switching on due to:
-

defective flame sensor (combisensor F691)

-

defective ECU (D871)

-

Cab heater does not start

5-1

Short circuit to earth or short circuit to supply of 
flame sensor (combisensor F691) on pins FF1 
and FF2 of the ECU (D871)

-

Cab heater does not start or fails during 
operation

5-2

Interruption of flame sensor (combisensor F691) 
on pins FF1 and/or FF2 of the ECU (D871)

-

Cab heater does not start or fails during 
operation

5-3

The flame sensor signal (combisensor F691) is 
out of range

-

Cab heater does not start or fails during 
operation

6-1

Short circuit to earth or short circuit to supply of 
thermostat unit (E566) temperature sensor on pin 
13 and/or 10 of the ECU (D871)

-

Cab heater does not start or fails during 
operation

6-2

Interruption of thermostat unit (E566) 
temperature sensor on pin 13 and/or 10 of the 
ECU (D871)

-

Cab heater does not start or fails during 
operation

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Airtronic (ACH-EA) fault codes

AIRTRONIC (ACH-EA)

DAVIE XD diagnostics manual 

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7-1

Short circuit to earth or short circuit to supply of 
fuel metering pump (B122) on pin 4 and/or 9 of 
the ECU (D871)

-

Cab heater does not start

Internal fault in fuel metering pump (B122)

7-2

Interruption on pin 4 and/or 9 of the ECU (D871), 
fuel metering pump (B122)

-

Cab heater does not start

Internal fault in fuel metering pump (B122)

8-1

Short circuit to earth or short circuit to supply of 
cab heater fan (B305) on pins BM1 and BM2 of 
the ECU (D871)

-

Cab heater does not start

Internal fault in fan (B305)

8-2

Interruption of cab heater fan (B305) on pins BM1 
and/or BM2 of the ECU (D871)

-

Cab heater does not start

Internal fault in fan (B305)

8-3

Cab heater fan (B305) speed deviation due to:
-

blocked vent

-

missing solenoid in electric motor

-

defective ECU (D871)

-

Cab heater fails during operation

9-1

Short circuit to earth or short circuit to supply of 
glow filament (B168) on pin GS1 and/or GS2 of 
the ECU (D871)

-

Cab heater does not start

9-2

Interruption of glow filament (B168) on pin GS1 
and/or GS2 of the ECU (D871)

-

Cab heater does not start

10-0

Cab heater gets overheated too often due to:
-

clogged hot air pipes

-

defective overheating sensor (combisensor 
F691)

-

insufficient supply of inlet air

-

Cab heater fails during operation

10-4

ACH-EA safety function switched on as a result 
of:
-

too many overheatings

-

The ECU is blocked

12-1

Short circuit to earth or short circuit to supply of 
thermostat unit (E566) on pin 10, 11 and/or 13 of 
the ECU (D871)

-

Cab heater does not start

-

Cab heater does not switch on or off at the 
desired temperature

Internal fault in thermostat unit (E566) or timer 
unit (E581)

12-2

Interruption of temperature unit (F566) on pin 10 
and/or 11 of the ECU (D871)

-

Cab heater does not start

-

Cab heater does not switch on or off at the 
desired temperature

Internal fault in thermostat unit (E566) or timer 
unit (E581)

13-1

Short circuit to earth or short circuit to supply of 
overheating sensor (combisensor F691) on pins 
UF1 and FF2 of the ECU (D871)

-

Cab heater does not start or fails during 
operation

Fault code

Fault code description with possible cause

Symptom

AIRTRONIC (ACH-EA)

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Airtronic (ACH-EA) fault codes

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DAVIE XD diagnostics manual

13-2

Interruption of overheating sensor (combisensor 
F691) on pins UF1 and/or FF2 of the ECU (D871)

-

Cab heater does not start or fails during 
operation

13-3

Combisensor (F691) value is out of measuring 
range due to:
-

clogged hot air pipes

-

defective overheating sensor (combisensor 
F691)

-

insufficient supply of inlet air

-

defective flame sensor (combisensor)

-

Cab heater does not start or fails during 
operation

Fault code

Fault code description with possible cause

Symptom