Audi Workshop Service and Repair Manuals > A2 > Heating, ventilation, air conditioning system | Heating, air conditioning system | Self diagnosis, V.A.G Inspection Service | Checking electric additional heater | Checking actuation of electric additional heater by engine control unit | Test requirements:

Checking actuation of additional heater by engine control unit: > < Checking actuation of electric additional heater by engine control unit

Test requirements:

Test requirements:

t	The engine is at ambient temperature (the coolant temperature is lower than 50 °C at the start of the test).

t	There is no fault saved in the engine control unit and in the operating and display unit for air conditioner/Climatronic -E87- → Chapter and → Relevant Workshop Manual, Diesel Direct Injection and Glow Plug System

t	Depending on the vehicle features, the following is set:

–	On the operating and display unit for air conditioner/Climatronic -E87- in vehicles with air conditioning: - Target temperature greater than 28 °C (e.g. “Hi”) - “Auto” mode (not “Econ”)

–	When the heater is activated in vehicles with a heater system: - Temperature rotary knob turned fully to “Warm” - Rotary knob for the fresh-air blower set to speed “3” - and with the Econ button not pressed (if there is one)

t	Additional consumers (e.g. heated rear window, heated seats) are switched off.

Heating, ventilation, air conditioning system
Heating, air conditioning system / Self diagnosis, V.A.G Inspection Service
Checking electric additional heater / ecking_actuation_of_electric_additional_heater_by_engine_control_unit/">Checking actuation of electric additional heater by engine control unit
Test requirements:

Checking actuation of additional heater by engine control unit: > < Checking actuation of electric additional heater by engine control unit