English-first OBD-II diagnostics Static, fast, focused lookup pages
CD CheckDTC Garage-grade fault lookup
Open P0300 Try AI Diagnose
Home / Codes / P0779
DTC code page

P0779: Pressure Control Solenoid B Intermittent

Quick answer: The controller detected an intermittent fault in the pressure-control-solenoid B circuit or command response.

Drivers also search this fault as pressure control solenoid B intermittent, PCS B intermittent fault, intermittent line pressure control B code.

Severity: high Family: powertrain Related paths: 9
Meaning

What P0779 usually means

P0779 is the intermittent version of the PCS B branch, which makes it especially useful for realistic owner-search behavior. A transmission may shift fine for days, then flare, slam, or enter limp mode only after a long drive, heat soak, or rough road. That pattern fits an intermittent pressure-control problem well. The fault can come from a harness that opens with movement, a solenoid that changes behavior as it warms up, connector contamination, or a valve-body issue that shows itself only when fluid thins out.

Fast triage

Start here before chasing parts

  • Scan first: save freeze-frame and pending codes before clearing anything.
  • Confirm the complaint: compare the stored code with current drivability symptoms.
  • Use context: trims, live data, and related codes usually narrow the fault faster than guesswork.
  • Work simplest to hardest: leaks, connectors, maintenance items, and known patterns before expensive components.
Initial checks

What to check first

  • Ask whether the complaint is tied to hot operation, long drives, or rough roads because intermittent pressure faults need that context.
  • Capture freeze-frame and note exactly how warm the transmission was when the code stored.
  • Inspect the connector early since intermittent pin tension and fluid contamination are common real-world causes.
Driving risk

Can you keep driving?

P0779 can feel harmless between episodes, but intermittent pressure loss or harsh max-pressure behavior can still accelerate wear. It should not be ignored if the transmission is occasionally flaring or slamming shifts.

High urgency: If symptoms are active, reduce driving and diagnose quickly before secondary damage builds.
Likely causes

Common causes behind this code

  • Pressure-control solenoid B fails intermittently as temperature changes
  • Harness or connector fault opens only with movement, vibration, or heat
  • Fluid contamination or valve-body wear causes pressure instability only when hot
  • Shared power or ground problem intermittently disrupts PCS B control
  • Controller driver issue that drops or distorts command unpredictably

Cause phrases often tied to this code: intermittent pressure control solenoid B, heat-sensitive harness fault, connector contamination, valve body issue when hot, intermittent TCM driver problem.

Diagnostic order

Suggested workflow

  1. Review freeze-frame and determine whether the problem appears only hot, only after long drives, or only with vibration.
  2. Road test long enough to reproduce the complaint while monitoring commanded pressure strategy and shift behavior.
  3. Inspect and manipulate the external harness and connector while checking for intermittent electrical dropouts.
  4. If the electrical side stays stable, widen the diagnosis to a heat-sensitive solenoid or valve-body pressure-control issue.
  5. After repair, confirm the transmission remains stable through the same long, warm operating conditions that used to trigger the code.
Avoid guesswork

Common mistakes

  • Declaring the fault fixed because the transmission behaves normally on a short cold drive.
  • Replacing major components without first proving the intermittent pattern electrically.
  • Ignoring how much the complaint depends on temperature and trip length.
Repair path

Practical fix guidance

  • Treat P0779 like a time-and-heat problem, not just a parts list problem.
  • Prioritize connector, harness, and solenoid verification before condemning the transmission internally.
  • Validate the fix with a realistic warm road test long enough to challenge the original failure condition.
Vehicle context

Affected brands in this MVP

Brand hubs help broaden internal linking now and can evolve into make-specific diagnostic notes later.

Aliases and common searches

English phrases tied to P0779

Useful when the driver knows the wording but not the exact DTC yet.

  • pressure control solenoid B intermittent
  • PCS B intermittent fault
  • intermittent line pressure control B code
Related search intent

Queries this page can answer naturally

  • P0779 code meaning
  • what does P0779 mean
  • pressure control solenoid B intermittent
  • PCS B intermittent symptoms
FAQ

Quick questions about P0779

Can P0779 come and go without obvious shifting problems every trip?

Yes. Many intermittent pressure-control faults show up only with heat, vibration, or long-drive conditions.

Is P0779 always electrical?

No. Intermittent hydraulic sticking or a heat-sensitive solenoid can also create it.

Why is P0779 harder to prove than P0778?

Because the fault may disappear in the bay and require the same time, heat, and motion that triggered it on the road.