Eberspächer Airtronic B5 Troubleshooting And Repair Instructions - page 20
Fault code
Fault description
Comments
Display
• Remedial action
Troubleshooting
20
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• Disconnect connector S1 / B1 at the heater and at the connector B1, PIN 16
check the cable up to the fresh air fan relay for short circuit to negative, if ok
–> replace control box, see page 28.
• Disconnect connector S1 / B1 at the heater and at the connector B1, PIN 15
check the cable up to the relay isolating switch or the car alarm input for short
circuit to negative, if ok –> replace control box, see page 28.
ADR shutdown due to signal change from (+) to (–) at connector S1, PIN 13 (D+)
or plus signal at connector S1, PIN 14 (HA+).
Overvoltage applied to control box for at least 20 seconds without interruption –
heater not working.
• Disconnect connector S1 / B1 at the heater, start the vehicle’s engine, measure
the voltage at connector B1 between PIN 1 (cable 2.5
2
rt) and PIN 10 (cable
2.5
2
br).
AIRTRONIC L 12 volt – voltage >16 volt —> check generator regulator.
AIRTRONIC L 24 volt – voltage >32 volt —> check generator regulator.
Undervoltage applied to control box for at least 20 seconds without interruption
– heater not working.
• Disconnect connector S1 / B1 at the heater, the vehicle’s engine is switched
off, measure the voltage at connector B1 between PIN 1 (cable 2.5
2
rt) and
PIN 10 (cable 2.5
2
br).
The measured value and the voltage at the battery should be the same. In case
of a voltage drop, check the fuses, the supply cables, the negative connections
and the positive support point on the battery for corrosion and correct
contact.
Temperature of the overheating sensor too high.
• Check hot air pipes for blockage –> remove blockage.
• Sum of the component ratings of air-conducting parts is too large –> Check air
system, if necessary re-lay – for component ratings, please refer to additional
parts catalogue.
• Check overheating sensor, for diagram and table of values please refer to
page 30, if ok –> measure fuel quantity, see page 33.
Flame sensor signals temperature at heat exchanger is too high.
• Check hot air pipes for blockage –> remove blockage.
• Sum of the component ratings of air-conducting parts is too large –> Check air
system, if necessary re-lay – for component ratings, please refer to additional
parts catalogue.
• Check flame sensor, if ok –> check overheating sensor, if overheating sensor
defective –> replace combination sensor, if overheating sensor ok –> measure
fuel quantity, see page 33, for diagram and table of values for flame sensor and
overheating sensor please refer to page 30.
Temperature difference between flame sensor and overheating sensor too large
• Check hot air pipes for blockage –> remove blockage.
• Sum of the component ratings of air-conducting parts is too large –> Check air
system, if necessary re-lay – for component ratings, please refer to additional
parts catalogue.
• Check flame sensor, if ok –> check overheating sensor, if overheating sensor
defective –> replace combination sensor, if overheating sensor ok –> measure
fuel quantity, see page 33, if fuel quantity ok –> replace control box, see
page 28. For diagram and table of values for flame sensor and overheating
sensor see page 30.
No faults
Warning:
Short circuit in control box, fresh
air output
Warning:
Short circuit in control box, car
alarm output
ADR shutdown
Overvoltage cutout
Undervoltage cutout
Overheating at the overheating
sensor (combination sensor)
Overheating at the flame sensor
(combination sensor)
Temperature difference between
flame sensor and overheating
sensor too large
000
004
005
009
010
011
012
013
014
4