Transmission Internal Mode Switch Logic
WARNING: This page is about a different car, the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Chevrolet Suburban 3500 HD, and 2018 Chevrolet Suburban. 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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