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Home >> Audi >> 2007 >> S4 Quattro Cabriolet (8HE) V8-4.2L (BHF) >> Repair and Diagnosis >> Heating and Air Conditioning >> Testing and Inspection >> Scan Tool Testing and Procedures >> Measured Value Blocks for Display Groups 011 Through 019 >> Display Group 018

Display Group 018






Display Group 018

The "ignition off" time period transmitted by the instrument cluster control module (J285), the transmitted assignment of the ignition key, the signal for windshield wiper operation transmitted by the steering column electronic systems control module (J527), and the operating state of the fresh air blower (V2) transmitted by the fresh air blower control module (J126)





• If no signal for the "ignition off time period " is detected by the Climatronic control module (J255) A/C control head during ignition activation, the Climatronic control module (J255) A/C control head assumes a standing time of greater than 4 hours and the engine temperature is assumed to be equal to the ambient temperature. As a possible consequence, the fresh air blower can start with a delay during heating mode although the engine is warm. In addition, the outside air temperature display (G106) in the instrument cluster can display incorrect outside temperature values.

• After 4 hours of standing time, the AClimatronic control module (J255) A/C control head assumes when calculating the temperatures that all parts of the vehicle have assumed the same ambient temperature.

• Depending on the hardware/software version of the Climatronic control module (J255) A/C control head, the display in this field is limited to the value stored in the Climatronic control module (J255) A/C control head (e.g. 3:59 h, 04:46 h) or the actual time is displayed.

• After the battery (A) is connected, the instrument cluster control module (J285) can perform a restart (reset) and therefore may not be able to transmit a time signal. If necessary, switch the ignition off for several minutes and check the displayed time period after the ignition is switched back on.





• The assignment of the ignition key can be detected and thus transmitted by the instrument cluster control module (J285) only in vehicles equipped with an immobilizer. Refer to => Vehicle Diagnosis, Testing and Information System VAS 5051 in the "guided fault finding" function (repair the instrument cluster)

• When switching on the ignition, the Climatronic control module (J255) A/C control head starts with the setting that was valid the last time the ignition was switched off with this key (temperature, air distribution, fresh air blower speed).

• If the ignition is switched on with a key (e.g. via the emergency start function) that is not activated for this vehicle, the Climatronic control module (J255) A/C control head from hardware/software version "0711" automatically switches to the operating mode " Off" after the ignition is activated and only the operating mode " Def" can be set with the ignition on (other settings not possible). The fault anti-theft immobilizer control module (J334) is stored at the same time in the Climatronic control module (J255) A/C control head. This function was included as part of theft protection improvement.





• Depending on the position of the switch for windshield wiper operation, several operating statuses can be displayed at the same time (e.g. " 01001" for wipe-wash mode and interval mode).

• Depending on the version, "1XXXX" can be displayed in vehicles without and with a rain sensor when the windshield wiper is on even when it is currently not raining (the Climatronic control module (J255) A/C control head assumes that it is raining and sets the display to "1XXXX" even though there is no signal from the rain sensor).

• The information regarding the operating status is needed to regulate the vent temperature at the evaporator and for vehicles with an air quality sensor (G238).









• If the activation of the fresh air blower is OK, and the fresh air blower control module (J126) does not identify a fault, the current fresh air blower speed is transmitted via a square wave signal to the Climatronic control module (J255) A/C control head. In the case of this square wave signal, the duty cycle is approx. 50% and the frequency 1/20 of the fresh air blower speed (example: in the case of a fresh air blower speed of 3000 rpm, the frequency of square wave signal is 150 hertz or pulses per second).

• If a fault is detected by the fresh air blower control module (J126), the fresh air blower control module (J126) transmits a square wave signal with a frequency of 10 Hertz (pulses per second). Via the duty cycle the Climatronic control module (J255) A/C control head detects the identified fault.
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