P2818 on GMC: How to Diagnose & Fix
Pressure Control Solenoid "H" Stuck On
1 GMC model · 1 documented issue · 1 critical · $900-$6,500 repair
P2818 on GMC by model: symptoms, diagnosis and fix
2024-2025 Sierra 1500 trucks with the 10-speed automatic (5.3L L84, 6.2L L87 and 3.0L Duramax LZ0) are failing at very low mileage with a stuck valve-body solenoid. Symptoms: a 'Service Transmission' or 'Service Transmission — Unable to Shift Soon' message, sudden hard/slamming shifts, slipping, complete loss of reverse (owners have had to push the truck out of parking spaces), and default limp operation limited to fifth gear and reverse. Several complaints report the failure occurring under 7,000 miles. NHTSA reports cite DTC P2818 (pressure control solenoid) and P0747/P0700. The situation is compounded by a national valve-body backorder — owners document 50-plus days and in some cases over a year waiting for the part, with GM sometimes authorizing a full transmission replacement instead. Complaint ODI numbers include 11756150, 11754176, 11748050, 11744152, 11739083, 11727368, 11721983, 11694617, 11684139, 11680422, 11680435, 11654431, 11644523, 11634982 (2024) and 11711937 (2025).
How to Fix
GM issued TSB #25-NA-255 (Sept 22, 2025) directing technicians to REPAIR rather than replace the valve body on 2021-2024 Silverado/Sierra 1500 and full-size SUVs with the 10L80/10L90 when P0747 is set. The repair installs a new steel Feed Limit Low Valve, a higher-tension Feed Limit Valve Spring, and a new valve body spacer plate with gasket; it requires at least 7,000 miles on the vehicle and must not be used if there is significant clutch debris in the pan. No solenoid characterization programming is needed afterward. Ask the dealer specifically for the 25-NA-255 repair kit rather than accepting a backordered complete valve body. Repairs are covered under the 5yr/60k powertrain warranty for these model years. If clutch material is present, a transmission replacement is the correct call.
Sources for this issue (2)
P2818 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 P2818 mean on a GMC?
P2818 stands for "Pressure Control Solenoid "H" Stuck On." SAE-defined generic powertrain/transmission code. Transmission pressure control solenoids meter line pressure to the clutch and band circuits so the transmission can change ratio smoothly. The transmission control module commands solenoid "H" off and then checks the resulting pressure, gear ratio and slip. P2818 sets when the module sees the hydraulic circuit still pressurised — the solenoid is stuck in the applied (on) state, either electrically or mechanically, so the element it feeds cannot release. The controller usually responds by forcing a failsafe or limp mode to protect the gearset. On GMC it is documented across 1 model: Sierra 1500.
What are the most common causes of P2818?
The most common causes of P2818 are: Pressure control solenoid stuck open/on, or its valve-body bore worn so the valve will not return, Valve body wear, debris or varnish holding the control valve in position, Low, burnt, overheated or contaminated transmission fluid; clogged filter, Open, shorted or chafed solenoid wiring, or a corroded internal transmission connector / pass-through, Failed transmission control module or internal control solenoid assembly, Worn clutch material circulating debris through the hydraulic circuit. The specific cause varies by vehicle.
How much does it cost to fix P2818 on a GMC?
Published repair estimates on GMC range from $900 to $6,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P2818 on a different make?
View P2818 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.