Diagnostic Aids
WARNING: This page is about a different car, the 2000 Isuzu Hombre. However, it is still accessible from the selected car via links, so may be relevant.
Check transmission range sensor harness connector for poor terminal connections. Check for damaged wiring harness or connectors. When DTC P0705 sets, PCM defaults to 3rd gear until correct inputs are received.
Voltage level of the circuits is LO (grounded) or HI (open). The 4 states displayed represents the encoder "P", "A", "B" and "C" in sequence. See SYSTEM WIRING DIAGRAMS article.