Idle Air Control Valve for Volkswagen 048 133 455

How Does an Idle Air Control Valve Work? (IAC) Introduction An IAC (idle air control) motor is designed to adjust the engine idle RPM speed by opening and closing an air bypass passage inside the throttle body. The cars computer or ECM (electronic control module) receives information from various sensors and will output signals to adjust the IAC motor in or out to adjust engine idle speed by controlling engine idle air. An IAC motor can fail one of two ways, either the motor short circuits and stops working or the motor will develop high resistance and cause the IAC control motor to react slowly, either failure can cause the engine to stall at idle. When a trouble code scan is performed it sometimes won't always detect a failed or weak IAC motor. To check the IAC motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the IAC should move in or out. If the IAC motor does nothing it has probably failed, replace it with a new unit and recheck system. Note: while the IAC motor is removed clean (use aerosol carburetor cleaner) the passages the IAC uses to control idle air speed, also inspect the IAC for a build-up on the seating (pointed) end and clean as necessary. Idle Control Valve OE NUMBER: HELLA 6NW 009 141-181 LUCAS FDB991 OE 048 133 455 SIEMENS VDO 408-202-013-002Z AUDI AUDI100 (4A, C4) 12/90 - 06/94 100 (4A, C4) 2.0 E ABK 4A,C4 1984 115 Saloon 4 12/90 - 06/94 AUDI AUDI80 (8C, B4) 06/93 - 12/94 80 (8C, B4) 2.0 E ABK 8C, B4 1984 115 Saloon 4 09/91 - 12/94 80 (8C, B4) 1.6 E ADA 8C, B4 1595 101 Saloon 4 06/93 - 12/94 AUDI AUDI80 Avant (8C, B4) 12/92 - 07/95 80 Avant (8C, B4) 2.0 E 16V quattro ACE 8C, B4 1984 140 Estate 4 12/92 - 07/95 AUDI AUDICABRIOLET (8G7, B4) 01/93 - 07/98 CABRIOLET (8G7, B4) 2.0 E ABK 8G7,B4 1984 115 Convertible 4 01/93 - 07/98 VOLKSWAGEN VOLKSWAGENCORRADO (53I) 08/91 - 12/95 CORRADO (53I) 2.0 i 16V 9A 1984 136 Coupe 08/91 - 12/95