P0779: Pressure Control Solenoid B Intermittent
What to do
Note whether the problem is worse hot or cold. That single observation separates a hydraulic leak from an electrical fault, and it is one only the driver is in a position to make.
What this code means
Pressure control solenoid B behaves inconsistently. Shift quality on the changes it governs varies between journeys or with temperature, which is the pattern worth testing against: fluid thins as it heats, so leakage past a worn bore rises with temperature, and a fault that appears only once thoroughly warm points at hydraulics rather than wiring.
Likely causes
Start here
- Faulty pressure control solenoid · moderate
- Worn valve body · specialist
- Damaged transmission wiring harness · moderate
Less common
- Low or degraded transmission fluid · easy
- Corroded transmission connector · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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