AD83.70-D-4000B | Auxiliary heater (AHE) diagnosis fault memory | 27.6.97 |
MODEL 901.###, 902.###, 903.###, 904.### ## up to 753730 up to 31.10.97 with CODE (H11) Warm air auxiliary heater
Heater unit designation B3L-C,
Heater unit designation D3L-C
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 put stationary heater/auxiliary heater or engine with heater booster into operation in confined spaces or while refuelling. Allow heater unit to cool down after operation and wear safety gloves. | |
Auxiliary heater (AHE) diagnosis, previous knowledge | |||
I | Battery voltage > 9.5 Volts | ||
II | Auxiliary heater complete (all connectors connected) | ||
III | Connect Hand-Held Tester (HHT) | ||
IV | Ignition and auxiliary heater switched on | ||
| Cables, plugs and connectors are also taken into account on the tests 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 code | Fault text (HHT) | Possible cause/Remedy | |
| Overvoltage shut-off | Check regulating voltage | |
| Undervoltage shut-off | Check fuse F9. Check battery and regulating voltage. Check electric cables (voltage drop) | |
| Overheating or metering pump –//– | Check inlet and outlet of hot air pipe for obstruction and eliminate obstruction if necessary Check electric cables and connections on metering pump. Check overheating switch | |
| Overheating of flame sensor | Check flame sensor and replace if necessary | |
| Glow plug –//– | Check glow plug and replace if necessary. Check electric cables and connections If in order, replace printed-circuit board | |
|
| Current regulator printed-circuit board –//– | Check electric cables. If in order, replace printed-circuit board | |
| Diagnosis output | Check electric cables | |
| Blower motor or speed regulator defective | Check connections to blower motor. Check motor and replace blower if necessary. If in order, replace printed-circuit board. | |
| Speed specified value signal | Check electric cables and connection. If in order, replace printed-circuit board | |
| Metering pump | Check metering pump and replace if necessary. Check electric cables and connections | |
| Too many attempts at starting | Control module lock-out due to failure to start 5 times in succession (refer to code ) | |
| Does not start | Check fuel supply. Check glow plug and replace if necessary. Check flame sensor | |
| Flame goes out during operation | Check fuel supply, quantity of fuel and blower speed. If combustion is in order, check flame sensor. | |
|
| Temperature sensor –//– | Check connector to temperature sensor. Check temperature sensor on printed-circuit board and replace printed-circuit board if necessary. | |
|
| Heater timer –//– | Check connections on heater timer and replace heater timer if necessary. | |
|
| Flame sensor –//– | Check connector to flame sensor. Check flame sensor and replace if necessary | |
| External interference voltages | Eliminate interference voltages | |
| Control module defective | Replace control module |