Transmission Internal Mode Switch Logic
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
| Gear Selector Position | Signal A | Signal B | Signal C | Signal P |
|---|---|---|---|---|
| Park | LOW | HI | HI | LOW |
| Park/Reverse | LOW | LOW | HI | LOW |
| Reverse | LOW | LOW | HI | HI |
| Reverse/Neutral | HI | LOW | HI | HI |
| Neutral | HI | LOW | HI | LOW |
| Neutral/Drive 6 | HI | LOW | LOW | LOW |
| Drive 6 | HI | LOW | LOW | HI |
| Drive 6/Drive 4 | LOW | LOW | LOW | HI |
| Drive 4 | LOW | LOW | LOW | LOW |
| Drive 4/Drive 3 | LOW | HI | LOW | LOW |
| Drive 3 | LOW | HI | LOW | HI |
| Drive 3/Drive 2 | HI | HI | LOW | HI |
| Drive 2 | HI | HI | LOW | LOW |
| Open | HI | HI | HI | HI |
| Invalid | HI | HI | HI | LOW |
| Invalid | LOW | HI | HI | HI |
| HI = Ignition voltage LOW = 0 volts |
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