Transmission Range Switch
WARNING: This page is about a different car, the 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, 2003 Chevrolet Monte Carlo, and 2003 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Transmission range switch may also be referred to as Park/Neutral Position Switch.
The Transmission Range (TR) switch is part of the Park/Neutral position and back-up light switch assembly and is externally mounted on the transmission manual shaft. See Fig 1 . The TR switch contains four internal switches that indicate the transmission gear range selector lever position. The PCM supplies ignition voltage to each switch circuit. By grounding one or more of the switch circuits, the PCM detects the selected gear range by the state change of the switch input. Switch input to the PCM 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.