Powertrain, generic · Transmission

P0779 Pressure Control Solenoid B Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Pressure control solenoids are current-controlled proportional valves, and what B and C mean depends on the design: on GM's clutch-to-clutch automatics they are the pressure valves of clutches 2 and 3, on GM's CVT B is primary pulley pressure and C line pressure, on Jatco CVTs B is the secondary pressure valve, on Saab's AF40 B and C are clutch valves SLC1/SLC2. In J2012 P0779 is an intermittent fault of valve B. The only manufacturer use found differs: Mitsubishi's 2022 Jatco CVT sets P0779 for an open circuit or short to positive in the secondary pressure valve circuit after 1 s (short to ground is P0778). The transmission then engages harshly, accelerates weakly and does not lock up.

Likely causes

Connector or wire open or loose contact
Short to positive in the harness
Valve coil faulty

Symptoms

  • Harsh engagement at times
  • Weak acceleration, no lock-up
  • Check engine light

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–2,000
Time1–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

pressure control solenoidtransmission valve bodytransmission clutchestransmission control module

Related codes

P0778P0776P0966P0967P0965

References: mitsubishitechinfo.com, mitsubishitechinfo.com, law.cornell.edu.