P0777 on Buick
Pressure Control Solenoid "B" Stuck On
P0777 on Buick vehicles indicates pressure control solenoid "b" stuck on. Au7o has documented this code across 1 Buick model — most commonly on Enclave. This code sets when the transmission control module determines that pressure control solenoid B is stuck in the ON/applied state and is not responding to commands to release. This solenoid regulates hydraulic pressure that controls clutch apply and shift feel, so a stuck solenoid causes incorrect line pressure. You may experience harsh shifts, slipping, or the transmission being locked into a particular pressure or gear. Prolonged operation can overheat and damage the transmission.
Common Causes of P0777
- •Pressure control solenoid B stuck mechanically
- •Debris or varnish in the valve body
- •Dirty or degraded transmission fluid
- •Low transmission fluid level
- •Internal valve body wear or sticking
- •Electrical fault in the solenoid circuit
- •Faulty transmission control module (less common)
P0777 on Buick by Model
Buick Enclave(1 issue)
- 3-5-Reverse Clutch Wave Plate Can Fracture (Special Coverage 14404)2008-2009
GM identifies some 2008-2009 Buick Enclave vehicles equipped with a 6T70/6T75 six-speed automatic transmission in which the 3-5-reverse clutch wave plate can crack or fracture. The documented result is loss of reverse, 3rd and 5th gears; drivers may also notice slip, flare or harsh shifts and a check-engine light.
Looking for P0777 on a different make?
View P0777 across all makes →Frequently Asked Questions
What does P0777 mean on Buick?▼
P0777 stands for "Pressure Control Solenoid "B" Stuck On." This code sets when the transmission control module determines that pressure control solenoid B is stuck in the ON/applied state and is not responding to commands to release. This solenoid regulates hydraulic pressure that controls clutch apply and shift feel, so a stuck solenoid causes incorrect line pressure. You may experience harsh shifts, slipping, or the transmission being locked into a particular pressure or gear. Prolonged operation can overheat and damage the transmission. On Buick specifically, this code is documented across 1 model.
What causes P0777 on Buick vehicles?▼
Common causes on Buick: Pressure control solenoid B stuck mechanically, Debris or varnish in the valve body, Dirty or degraded transmission fluid, Low transmission fluid level, Internal valve body wear or sticking. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0777 on a Buick?▼
Repair costs vary widely depending on the root cause and specific Buick model.
Which Buick models have P0777 documented?▼
Au7o has documented P0777 on 1 Buick model: Enclave.