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P0777 Powertrain

Pressure Control Solenoid B Stuck On

Pressure control solenoid B does not release line pressure when commanded — output pressure remains at maximum, leading to harsh shifts and elevated stress on the clutch packs and seals.

Affected components

  • Pressure control solenoid b
  • Valve body

Common causes

  • High likelihood: Solenoid stuck open by debris
  • Medium likelihood: Contaminated ATF clogging the pressure control valve
  • Low likelihood: Carbon or debris buildup preventing free movement

Possible symptoms

  • Check engine or transmission warning light on
  • Harsh, delayed, or missing shifts
  • Possible limp mode (locked in one gear)
  • Slipping or shuddering during gear changes

Diagnostic notes

  • The malfunction indicator lamp may illuminate

Related codes

Sources

Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.

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