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Home >> Saab >> 1991 >> 900 Base, 2D Convertible, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> Theory and Operation >> Engine Controls - Theory & Operation >> Computerized Engine Controls >> Control Units >> Automatic Performance Control (APC) ECU (Turbo)
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Automatic Performance Control (APC) ECU (Turbo)

The APC system ECU is located under the dash, left of the steering column. It receives signals from a detonation sensor, pressure sensor and ignition system ECU. The APC ECU processes these signals and sends a signal to a solenoid valve at the turbocharger to control optimum boost pressure.

NOTE: Components are grouped into 2 categories. The first category covers INPUT DEVICES, which control or produce voltage signals monitored by the control unit. The second category covers OUTPUT SIGNALS, which are components controlled by the control unit.