As a result, the auxiliary heater increases the temperature of the coolant to provide sufficient heating for the air passing through the heat exchanger.
The maximum power of the additional heater is 5 kW, and the minimum is 2.2 kW.
A fuel pump connected to the auxiliary heater supplies diesel fuel from the fuel supply line to the prechamber.
An additional pressure control valve is installed upstream of the fuel pump to reduce the fuel pressure to below 0.2 bar.
The exhaust gases are expelled to the outside through a separate exhaust system.
Smoke generated when the auxiliary heater is switched on for the first time is normal and is a consequence of the nature of the combustion process.
Auxiliary heater is automatically activated after engine start (D+ signal from generator activated), if the outside temperature is below 5°C and the coolant temperature is below 75°C. The coolant temperature is controlled by the system whenever the vehicle is in operation.
The system is not automatically activated if the coolant temperature reaches 85°C or if it does not function properly.
The system shuts down under the following conditions:
- if after the second attempt to start ignition does not occur (after a pause of 90 seconds)
- if the flame goes out during operation, and the second attempt to start the heater is unsuccessful
- if overheating triggers the overheating sensor
- if the voltage exceeds/falls below the prescribed value, or if the power supply to the glow plug or dosing pump is interrupted
- if the fan wheel is blocked or defective.
Additional heater in section
| Pos. | Spare Part No | Name |
| 1 | - | Combustion chamber fan |
| 2 | - | Flame sensor |
| 3 | - | glow plug |
| 4 | - | Coolant outlet |
| 5 | - | temperature sensor |
| 6 | - | Overheating sensor |
| 7 | - | coolant inlet |
| 8 | - | fuel line |
| 9 | - | Exhaust gases |
| 10 | - | fuel injection pump |
| 11 | - | Fresh air intake |
| 12 | - | Electronic control unit |
Expanded image - auxiliary heater
| Pos. | Spare Part No | Name |
| 1 | - | Cooling sleeve cover |
| 2 | - | Combustion chamber fan cover |
| 3 | - | Electronic control unit |
| 4 | - | Combustion chamber fan |
| 5 | - | Cooling sleeve |
| 6 | - | glow plug |
| 7 | - | Flame sensor |
| 8 | - | Overheating sensor |
| 9 | - | temperature sensor |
| 10 | - | Compression spring |
| 11 | - | O-ring of circular cross-section |
| 12 | - | Wiring harness |
| 13 | - | Pad |
| 14 | - | Pad |
| 15 | - | heat exchanger |
| 16 | - | The combustion chamber |
| 17 | - | O-ring of circular cross-section |
| 18 | - | fan motor cover |
| 19 | - | Adapter |
| 20 | - | Glow plug wiring harness |
Electric auxiliary heater (automatic action)
Diesel vehicles for the European market (except Scandinavia), will be equipped with an electrically powered auxiliary heater.
Settings for the auxiliary heater with three glow plugs (0; 1; 2; 3) controlled by the powertrain control module (RSM) and switched by two relays. The control of the PCM ensures that sufficient battery charge is maintained. The auxiliary heater is switched off when the demand for electricity for all the switched on loads causes the battery charge level to drop. To control the auxiliary heaters, the PCM evaluates the following signals:
- cylinder head temperature
- air intake temperature,
- generator state of charge (ALFF).
CAUTION: Glow plugs cannot be replaced. The threaded connection has a one-time seal. The auxiliary heater must be replaced as an assembly.
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