P182E on 2018-2022 GMC Terrain (SL, SLE, SLT, Denali) — Internal Mode Switch Invalid Range
1 vehicles · 1 makes · $150-$1,500 repair
How to diagnose and fix P182E: most-reported vehicles
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GMC Terrain · 2018–2022
Second-generation Terrains with the electronic precision (push-button/monostable) shifter throw a persistent "Shift to Park" warning and refuse to shift out of (or fully into) park even when correctly positioned. GM traced it to build-up/contamination on the Park switch contacts in the transmission control (shifter) assembly, causing high resistance so the BCM cannot electronically confirm the Park position. It can strand the vehicle and, in many cases, keeps the ignition from turning off (stuck in Accessory).
Common Symptoms
- "Shift to Park" message won't clear
- Cannot shift out of park
- Cannot turn engine off (stuck in Accessory)
- Intermittent no-shift condition
- Warning chime persists
How to Fix
GM issued field actions ranging from an ECM/BCM software update to a shifter wire-harness/jumper change and ultimately replacement of the shifter control (transmission control button) assembly. Dealers first clear the fault; recurring cases get a new shifter cartridge or full center-console shifter unit.
Sources for this issue (1)
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P182E code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P182E mean?
P182E stands for "Internal Mode Switch Invalid Range." A GM-specific transmission code (Chevrolet, GMC, Buick, Cadillac). The internal mode switch sits inside the transmission and is moved by the shift cable to tell the transmission control module which gear range the driver selected. P182E sets when the switch does not indicate a valid Park, Reverse, Neutral, or Drive position. The transmission usually falls back to a default or limp strategy, so expect harsh or limited shifting, no gear engagement, a no-crank condition, or a gear indicator that shows the wrong range.
What are the most common causes of P182E?
The most common causes of P182E are: Failed internal mode switch (manual shift position switch) inside the transmission, Misadjusted, stretched, or disconnected shift cable so the switch never reaches a valid detent, Damaged or corroded internal transmission wiring harness or pass-through connector, Low or contaminated transmission fluid, Poor ground or chafed wiring between the switch and the transmission control module, Faulty transmission control module. The specific cause varies by vehicle.
How much does it cost to fix P182E?
Repair costs for P182E range from $150 to $1,500, depending on the vehicle and root cause.
Which vehicles are affected by P182E?
Au7o has documented P182E across 1 vehicle models from 1 manufacturers: GMC.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.