The control unit regulates the operation of the heater and controls the combustion process in accordance with the readings of the flame sensors, air temperature at the inlet and outlet of the heater, the position of the thermostat handle. Built-in temperature sensor can be replaced by an external one. If a malfunction occurs, the control unit diagnoses the heater and issues a malfunction code. Depending on the configuration of the heater, on the display of the combi-timer (in the form of numbers) or on the switch indicator (in the form of a block code - blinking). In addition, the heater can be diagnosed using a diagnostic adapter and a PC.
1. Remove the heater.
2. Disassemble the housing.
3. Carefully open the retainer on the impeller of the air blower (2 flat-head screwdrivers).
4. Remove the blower impeller from the shaft.
5. Remove the connectors from the control unit.
6. Unscrew the screws and remove the control unit.
7. Perform repair work with the elements removed.
Note: The control unit repair is not subject to.
1. Place the control unit in the installation position and secure with screws.
2. The tightening torque of the screws 0.7 ± 0.07 Nm.
3. Slip the impeller of the air blower onto the motor shaft. Drain it until it clicks into the groove on the shaft.
4. Connect the plug connectors to the control unit.
5. Assemble the housing parts.
6. Install the heater on the vehicle.
7. Check the CO2 value, adjust if necessary.
8. Check the ease of rotation of the impeller by hand. With the subsequent inclusion to pay attention to possible noises.
ATTENTION! The impeller must be free of foreign objects.