Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Ford >> 1991 >> Bronco 4.9 Y, Standard, M5OD-R2 >> Repair and Diagnosis >> Engine Performance >> Theory and Operation >> Engine Controls - Theory & Operation >> Input Devices >> Vehicle Speed Sensor (VSS)

Vehicle Speed Sensor (VSS)

The transmission-mounted VSS sends a pulsing signal to ECA when vehicle is moving. The VSS generates pulses with axle shaft revolution. The ECA interprets speed sensor input along with TPS closed throttle input.

This input enables ECA to differentiate between closed throttle deceleration and closed throttle idle (vehicle stopped) conditions. During deceleration, ECA controls Idle Speed Control (ISC) Valve to maintain a desired manifold pressure. During idle, ECA controls ISC motor to maintain a desired idle speed.

scientia non olet · About Mike's Workshop Manuals