HEATING OUTPUT AND TEMPERATURE DOOR ACTIVATION, CHECKING, "Convenience" VERSION: Notes

WARNING: This page is about a different variant/trim than selected.

Test Requirements Are Met. Refer To HEATING OUTPUT AND TEMPERATURE DOOR ACTIVATION, TESTING REQUIREMENTS .

-- Close the engine hood.

-- Close the doors, the windows, the sunroof and the rear lid.

-- Open all instrument panel vents.

-- Turn on the ignition and activate the ready mode, the engine start by itself if needed (high voltage vehicles).

-- Start the engine (not high voltage vehicles).

Set The Following On The Climatronic Control Module -J255- A/C Display And Control Head:

"Auto" for the driver and passenger side (the indicator lamp in the AUTO buttons come on).
Temperature preset for the driver and front passenger side set to "cold" ("LO" in the Climatronic Control Module -J255- or in the MMI display).
A/C compressor is turned on (the indicator lamp in the AC or A/C button turns on).
Preset for the fresh air blower "maximum speed" (in the Climatronic Control Module -J255- display and in the MMI display, setting "10" or greater).
Set the airflow direction using the knob on the A/C display and control head for the driver and passenger side to "footwell" and "instrument panel vents" (in the Climatronic Control Module -J255- and in the MMI display)

NOTE:

The Indicator Lamp In The AUTO - Buttons Turns Off When Performing Manual Changes For The Airflow Direction And/Or The Fresh Air Blower Speed.

The maximum possible fresh air blower speed depends on several conditions (coolant temperature, vehicle voltage, etc.)

If the dial for setting the driver side temperature is held for a longer time, then this setting will be taken over as well for the passenger side.

-- Set the Rear Temperature Selection Potentiometer -G538- to "cold" (installed in the rear center console vent).

-- Open the vents in the rear center console.

-- Initiate the Guided Fault Finding for the A/C system and select the "Read measuring value block" function, using the Vehicle Diagnostic Tester in the "Guided Fault Finding " function.

-- Let the A/C system run several minutes at maximum cooling output (A/C compressor is switched on, indicator lamp in the AC or A/C button comes on).

-- Compare the Evaporator Vent Temperature Sensor -G263- measured value with the measured values of the Left Front Upper Body Vent Temperature Sensor -G385-, the Right Front Upper Body Vent Temperature Sensor -G386-, the Left Footwell Vent Temperature Sensor -G261- and the Right Footwell Vent Temperature Sensor -G262-).

SPECIFIED VALUES:

The measured values of the temperature sensor after heat exchanger (Left Front Upper Body Vent Temperature Sensor -G385-, Right Front Upper Body Vent Temperature Sensor -G386-, Left Footwell Vent Temperature Sensor -G261- and Right Footwell Vent Temperature Sensor -G262-) may be a maximum of 5 °C (41 °F) greater than the value of the Evaporator Vent Temperature Sensor -G263- after five minutes.

If the required values are not reached, perform a fault finding at a temperature increase on the evaporator. Refer To TEMPERATURE INCREASE DOWNSTREAM FROM EVAPORATOR, DETERMINING MALFUNCTION .

-- Using a commercially available thermometer, measure the air coming out of the vents in the rear center console and the rear footwell vents (left and right under the front seats) and compare the measured values with the temperatures displayed in the measured values block.

SPECIFIED VALUES:

The measured values may be 5 °C (41 °F) greater than the displayed measured values for the temperature sensor.

If the required values are not reached, perform a fault finding at a temperature increase on the evaporator. Refer To TEMPERATURE INCREASE DOWNSTREAM FROM EVAPORATOR, DETERMINING MALFUNCTION

-- Using the knob on the Climatronic Control Module -J255- A/C display and control head, select the "warm" temperature setting for the front passenger side ("HI" in the Climatronic Control Module -J255- and in the MMI display).

-- Read the measured values displayed for the temperature sensor in the measured value block (Evaporator Vent Temperature Sensor -G263-, Left Front Upper Body Vent Temperature Sensor -G385-, Right Front Upper Body Vent Temperature Sensor -G386-, Left Footwell Vent Temperature Sensor -G261- and Right Footwell Vent Temperature Sensor -G262-).

-- Using a commercially available thermometer, measure the temperature of the air coming out of the vents in the rear center console (left and right).

SPECIFIED VALUES:

The temperature at the Right Front Upper Body Vent Temperature Sensor -G386- and Right Footwell Vent Temperature Sensor -G262- increases to above 52 °C (126 °F) (depending on the engine temperature at the time).
The temperature at the Left Front Upper Body Vent Temperature Sensor -G385- and Left Footwell Vent Temperature Sensor -G261- increases by less than 10 °C (50 °F) in contrast to the measured value of the Evaporator Vent Temperature Sensor -G263-.
The measured temperature of the air coming out of the vents in the rear center console increases by less than 20 °C (68 °F).