A6 Sedan V6-3.2L (BKH) (2007)
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Connect DSO measuring leads 1 & 2 (VAS 5051/8) to adapter leads.
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Measuring lead (signal wire) to terminal - 2 - of connector - A -
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Measuring lead (shielding, Ground) to terminal - 1 - of connector - A -
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In Vehicle Diagnosis, Testing and Information System (VAS 5051 A), select operating mode Test Instruments: DSO (digital storage oscilloscope),
a => Vehicle Diagnosis, Testing and Information System VAS 5051 in function "Guided fault finding".
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Make the following setting at the Vehicle Diagnostic, Testing and Information System (VAS 5051 A): 5V/div = 0.5ms/div (5V DC and 0.5
milliseconds per unit)
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Start engine.
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At the Climatronic Control Module (J255) A/C control head, set the temperature preselect for the driver's and front passenger's side to maximum
cooling (e.g., to temperature setting " Lo", or turn both rotary switches to the "cold stop" position).
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Switch on and off the controller of the A/C compressor regulator valve (N280) via the Climatronic Control Module (J255) A/C control head by
pressing the Auto, Econ ON/OFF or A/C and ON/OFF buttons.
Shown on screen of oscilloscope, depending on setting of A/C control head Climatronic Control Module (J255):
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No square wave signal (A/C Compressor Regulator Valve (N280) is not activated) for operating mode "OFF" and " Econ" or "A/C off".
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A square wave signal with an impulse width - A - between 75% and 100% (A/C compressor regulator valve (N280) is activated) for operating
mode "Auto" and temperature setting "Lo".
‹› The Fig. shows a signal with a duty cycle of approximately 80%.