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Home >> Oldsmobile >> 1987 >> Cutlass Ciera V6-173 2.8L >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Transmission Position Sensor/Switch >> Description and Operation
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Transmission Position Sensor/Switch: Description and Operation

PURPOSE
The Park/Neutral (P/N) switch indicates to the Electronic Control Module (ECM) when the transmission is in Park, Neutral or Drive. This information is used for the Torque Converter Clutch (TCC), Exhaust Gas Recirculation (EGR) and the Idle Air Control (IAC) valve operation.

OPERATION
The park/neutral switch contacts are a part of the neutral start switch and are closed to ground in park or neutral, and open in drive ranges. The ECM supplies ignition voltage through a current limiting resistor to CKT 434 and senses a closed switch when the voltage on CKT 434 drops to less than one volt.

CAUTION: Vehicle should not be driven with park/neutral switch disconnected, as idle quality will be affected and a possible false Code 24 Vehicle speed Sensor (VSS).

Refer to Refer to System Diagnosis / C-charts Component Testing / Chart C-1A for P/N Switch Diagnosis.
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