P0778 Code: Pressure Control Solenoid B Electrical
🟠 Moderate severity · drivable
Drivable, but shifting may be harsh or erratic. Fix it soon to avoid transmission damage.
What P0778 means
There's an electrical fault in the pressure control solenoid B circuit, so the computer can't control transmission hydraulic pressure.
Symptoms
- Check engine light is on
- Harsh or erratic shifting
- Slipping between gears
- Possible limp mode
Common causes
- most common: Faulty pressure control solenoid
- common: Damaged wiring or loose connector
- common: Low or dirty transmission fluid
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Replace the pressure control solenoid | Mechanic | $200–500 |
| Check and change the transmission fluid | Yes | $100–250 |
Frequently asked questions
Can I drive with a P0778 code?
Yes, but shifting may be harsh. Fix it soon.
What is the most common cause of P0778?
A faulty pressure control solenoid or damaged wiring.
How much does it cost to fix a P0778?
$200–$500 for a new solenoid.
Related codes
P0776
P0776 Code: Pressure Control Solenoid B Stuck Off
P0777P0777 Code: Pressure Control Solenoid B Stuck On
P0700P0700 Code: Transmission Control System Malfunction
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.