90 Quattro 20V (Canada) L5-2309cc 2.3L DOHC (7A) (1989)
Active Check Module: Description and Operation
Circuit Description
The Auto-Check system monitors individual Systems and informs the driver of malfunctions via liquid-crystal display (LCD) warning indicators on the
instrument panel.
Malfunctions are classified in two groups: Warning Display and Danger Display.
The Warning Display group includes:
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Brake lights
-
Headlights (low-beam)
-
Taillights
-
Battery and charging system voltage
-
Windshield washer fluid level
-
Fuel level
If a defect occurs in the Warning Display group, the appropriate indicator will appear and a buzzer will sound once. For some defects, a yellow warning
triangle will also be illuminated.
If there is more than one defect, the appropriate indicators will appear one after the other. Warning Display group faults are suppressed if there is more
than one fault in the Danger Display group.
The Danger Display group includes:
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Brake fluid level
-
Engine coolant level
-
Engine coolant temperature
-
Engine oil pressure
If a defect occurs in the Danger Display group, the appropriate indicator will appear along with a red warning triangle, and a buzzer will sound three
times.
The Auto-Check control unit receives power via fuse #8 (S8) on the main fuse/relay panel. Components in the instrument cluster receive power via
fuses #4 (S4), #12 (S12) and #14 (S14).
WARNING: The driver-side airbag is an explosive device. Before removing the steering wheel or steering column switches, always disconnect the
airbag power-supply connector, refer to "Air Bag Systems" for more information.