P0776 on Cadillac: How to Diagnose & Fix
Pressure Control Solenoid B Performance/Stuck Off
1 Cadillac model · 1 documented issue · $300-$3,500 repair
P0776 on Cadillac by model: symptoms, diagnosis and fix
The GM 6L50 6-speed automatic transmission in V6-equipped STS models is prone to overheating and developing harsh shift quality. The transmission fluid cooler is undersized for the vehicle weight, and the valve body solenoids degrade from heat cycling. Fluid darkens rapidly, and shift quality deteriorates with delayed or slipping 3-4 and 5-6 upshifts. The torque converter clutch also fails prematurely from heat damage.
Common Symptoms
- Harsh or delayed 3-4 upshift
- Transmission fluid dark or burnt smell by 50,000 miles
- Transmission temperature warning
- Torque converter shudder at 40-50 mph light throttle
- Slipping in higher gears under load
How to Fix
Perform a complete transmission fluid and filter change (not a flush) every 30,000 miles using Dexron VI. Install an auxiliary transmission cooler for vehicles used in hot climates or towing. If shifts are already harsh, a valve body rebuild or replacement with updated solenoids may be required. Torque converter replacement is needed if shudder is present.
Sources for this issue (1)
P0776 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 P0776 mean on a Cadillac?
P0776 stands for "Pressure Control Solenoid B Performance/Stuck Off." This code means the transmission's Pressure Control Solenoid B is not performing correctly and is behaving as if stuck in the 'off' position. Pressure control solenoids regulate the hydraulic fluid pressure used to apply clutches and bands and to control shift quality, so when one underperforms the transmission may shift harshly, slip, flare between gears, or feel inconsistent. The transmission control module sets this code when the fluid pressure or response it measures doesn't match what it commanded from that solenoid. It generally indicates a hydraulic performance issue with the solenoid or its fluid circuit rather than just a wiring fault. On Cadillac it is documented across 1 model: STS.
What are the most common causes of P0776?
The most common causes of P0776 are: Stuck or failed pressure control solenoid B, Low, dirty, or degraded transmission fluid, Clogged solenoid screen or valve body passages, Sticking or worn valve body components, Wiring or connector problem at the solenoid, Internal transmission wear or pressure loss, Faulty transmission control module. The specific cause varies by vehicle.
How much does it cost to fix P0776 on a Cadillac?
Published repair estimates on Cadillac range from $300 to $3,500 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 P0776 on a different make?
View P0776 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.