Park/Neutral Position Switch
The transmission range (TR) switch is part of the park/neutral position (PNP) and back-up lamp switch assembly (1), which is externally mounted on the transmission manual shaft. The TR switch contains four internal switches that indicate the transmission gear range selector lever position. The TCM supplies ignition voltage to each switch circuit. By grounding one or more of the switch circuits, the TCM detects the selected gear range by the state change of the switch input. Refer to Transmission Range Switch Logic . Switch input to the TCM is represented on the scan tool as HI and LOW. HI indicates an ignition voltage signal. LOW indicates a zero voltage signal. The four parameters represent transmission range switch signal A, B, C and Parity.