Electric Booster Heater: Overview

Electric Booster Heater

OVERVIEW
Due to the slower warm up times associated with the diesel engine, an electric booster heater may be fitted to increase heater performance. The electric booster heater does this by heating the air leaving the heater assembly. The electric booster heater comprises ceramic coated thermistor elements and a microcontroller. A request for electric booster heater operation originates in the ATC (automatic temperature control) module. This request is transmitted to the CJB (central junction box) over the medium speed CAN (controller area network) bus. The CJB (central junction box) interprets this request and outputs a PWM (pulse width modulation) signal to the electric booster heater microcontroller. The duration of the pulses provided by the CJB (central junction box) is proportional to the amount of heating required.
The amount of heating requested by the ATC (automatic temperature control) is based on:
- Ambient air temperature
- ECT (engine coolant temperature)
- Heating request.

NOTE:
There is also a minimum blower motor speed required by the electric booster heater operation.
The electric booster heater is limited to 1.25 kW. If electrical load management is in force, electric booster heater performance will be reduced.