Grand Prix V6-204 3.4L DOHC (1992)
Transmission Position Switch/Sensor: Testing and Inspection
Chart C-1A Park/Neutral Switch Diagnosis
Park/Neutral Switch Circuit Diagram
CIRCUIT DESCRIPTION
The Park/Neutral (P/N) switch gets a 12 volt reference from the PCM, and the PCM monitors the circuit. When the switch is in the park or neutral
position, it grounds the circuit, causing a drop in the circuit voltage. Low voltage in circuit 434 indicates the transmission is not in a drive gear. The PCM
uses this information for the following:
^ Idle Air Control valve operation
^ Vehicle Speed Sensor diagnosis
^ EGR control
^ Torque Converter Clutch Control
NOTE: If circuit 434 indicates Park/Neutral while transmission is in a drive range (circuit 434 voltage low - switch grounded), the EGR system will not
operate and engine may "PING" under load. If circuit 434 voltage remains high (circuit open) while transmission is in Park/Neutral, a drop in
idle speed may be noticed when transmission is placed in a drive range.
TEST DESCRIPTION
