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Vehicle Speed Sensor-PCM Input

DESCRIPTION
The sensor input is used by the Powertrain Control Module (PCM) to determine vehicle speed and distance traveled.

OPERATION
The speed sensor generates 8 pulses per sensor revolution. These signals, in conjunction with a closed throttle signal from the throttle position sensor, indicate a closed throttle deceleration to the PCM. When the vehicle is stopped at idle, a closed throttle signal is received by the PCM (but a speed sensor signal is not received).

Under deceleration conditions, the PCM adjusts the idle air control (IAC) motor to maintain a desired Manifold Absolute Pressure (MAP) value. Under idle conditions, the PCM adjusts the IAC motor to maintain a desired engine speed.

LOCATION

Fig. 18 Vehicle Speed Sensor Location - 2WD:




The vehicle speed sensor is located on the speedometer pinion gear adapter. The pinion gear adapter is located on the extension housing of the transmission (drivers side).