Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2001 GMC Savana Special, 2001 GMC Savana Camper Special, 2001 GMC Savana, 2001 Chevrolet RV Cutaway, and 2001 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
Inspect wiring for poor connections at control module and TR switch. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wires that could short to bare metal or other wiring. Check for broken wire inside insulation. If diagnosing for intermittent short or open condition, move wiring harness while observing scan tool for value changes. For valid combinations of switch signal circuits "A", "B", "C" and "P" (Parity), see TRANSMISSION RANGE SWITCH LOGIC table.
TRANSMISSION RANGE SWITCH LOGIC (1)
| Gearshift Lever Position | Signal "A" | Signal "B" | Signal "C" | Signal "P" | ||
|---|---|---|---|---|---|---|
| Park | LOW | HI | HI | LOW | ||
| Reverse | LOW | LOW | HI | HI | ||
| Neutral | HI | LOW | HI | LOW | ||
| "OD" | HI | LOW | LOW | HI | ||
| "3" | LOW | LOW | LOW | LOW | ||
| "2" | LOW | HI | LOW | HI | ||
| "1" | HI | HI | LOW | LOW | ||
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