AD83.70-D-4000F | Auxiliary heater (AHE) diagnosis fault memory | 21.7.98 |
MODEL 901.###, 902.###, 903.###, 904.### ## as of 753731 as of 3.11.97 with CODE (H11) Warm air auxiliary heater
Heater designation B3L-C compact,
Heater designation D3L-C compact
Danger! | Risk of explosion due to fuel vapors, risk of poisoning from inhaling combustion gases and risk of injury from burns during or after heater operation | Do not start stationary heater/auxiliary heater with engine booster in confined spaces or while refueling. Allow heater to cool down after operation and wear safety gloves. | |
Auxiliary heater (AHE) diagnosis, previous knowledge | |||
I | Battery voltage > 10.5 volts | ||
II | Auxiliary heater complete (all connectors connected) | ||
III | Connect Hand-Held Tester (HHT) | ||
IV | Ignition and auxiliary heater all switched on | ||
| Cables, plugs and connectors are also taken into account during testing with the HHT and, if a fault is displayed, may have to be checked again separately in accordance with the relevant electric wiring diagram for open circuit, good contact and correct connection | ||
Fault memory | |||
Fault code | Fault text (HHT) | Possible cause / remedy | |
| Control module fault | Replace control module | |
| Control module fault, internal temperature sensor | Replace control module | |
| Does not start | Check fuel supply, glow plug and flame sensor | |
| Too many attempts at starting | Failure to start 10 times in succession (refer to code ) | |
| Flame goes out | Check fuel supply and quantity of fuel If combustion is in order, check flame sensor | |
| Overvoltage | Check regulating voltage | |
| Undervoltage | Check fuse F9. Check battery and regulating voltage. Check electric cables (voltage drop) | |
| Premature flame recognition | Check flame sensor | |
|
| Flame sensor –//– | Check flame sensor and replace if necessary | |
|
| Metering pump –//– | Check metering pump and replace if necessary Check electrical cables and connections | |
| Incorrect blower motor speed | Check blower motor, replace blower if necessary | |
|
| Glow plug –//– | Check glow plug, replace if necessary Check electrical cables and connections | |
| Overheating | Check hot air pipe inlet and outlet for obstruction, remove obstruction if necessary Check overheating sensor | |
| Frequent overheating | Check hot air pipe inlet and outlet for obstruction, remove obstruction if necessary Check overheating sensor Check flame sensor | |
|
| Potentiometer –//– | Check heater timer connections and replace timer if necessary | |
|
| Overheating sensor –//– Outside tolerance | Check overheating sensor and replace if necessary |
Referenced documents
- ad0000d200003a Connecting hand-held tester (HHT), reading fault memory
- ad8370d2000d Auxiliary heater (AHE) diagnosis previous knowledge
- as8370z000201a Risk of explosion caused by fuel vapors igniting, risk of poisoning caused by inhaling combustible gases and risk of injury caused by burns during and after operation of heater unit