Transmission

P0776 — Pressure Control Solenoid B Performance or Stuck Off

Severity: medium Drive with care, to a shop

What P0776 means

The transmission control module compares commanded line pressure with actual pressure, judged from clutch slip and sensor data. Pressure control solenoid B regulates one of the hydraulic pressure circuits in the valve body. P0776 sets when the solenoid fails to deliver the requested pressure or stays stuck in the off position.

Symptoms

  • Harsh or erratic shifts
  • Transmission goes into limp mode
  • Check Engine or transmission warning light on
  • Slipping during acceleration
  • Delayed engagement into Drive or Reverse
  • Transmission stuck in one gear

Possible causes

  1. Failed pressure control solenoid B
  2. Sticking or worn valve body spools
  3. Low or degraded transmission fluid
  4. Weak pump output and low line pressure
  5. Clogged transmission filter
  6. Damaged, open or corroded wiring or connector at the solenoid
  7. Faulty transmission control module (rare)

How to diagnose

  1. Scan all codes and freeze frame data, and note any other transmission codes
  2. Check fluid level and condition: color, smell, metal debris
  3. Inspect the transmission wiring harness and connector for damage, moisture and corrosion
  4. Measure solenoid resistance and compare with specification
  5. Check power supply and ground on the solenoid circuit
  6. Command the solenoid with a scan tool and watch the pressure response
  7. Measure actual line pressure with a gauge
  8. Drop the pan and inspect the filter and valve body

Common fixes

  • Change transmission fluid and filter
  • Replace pressure control solenoid B
  • Repair the wiring or connector
  • Clean or rebuild the valve body and replace worn spools
  • Replace the oil pump if pressure is low
  • Reprogram or replace the transmission control module if it is faulty

Questions and answers

What does P0776 mean?

It is a fault in pressure control solenoid B inside the automatic transmission. The solenoid is not doing what the control module commands, or it is stuck off, so hydraulic pressure is wrong.

Can I drive with P0776?

Only for a short distance and with care, such as to a repair shop. Driving long with incorrect pressure wears the clutches faster and can lead to a costly transmission repair.

Will a fluid change fix P0776?

Sometimes, if dirty or worn fluid and a clogged filter are the cause. If the solenoid is electrically bad or mechanically stuck, it needs replacing or the valve body needs repair.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.