Error code

OBD2 P0778

OBD2P0778
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Pressure Control Solenoid 'B' Electrical.

Severity

moderateCan be driven but may experience harsh shifts and other issues.

Summary

P0778 indicates an electrical malfunction with pressure control solenoid B in the transmission.

Symptoms

  • Stored trouble code and possibly an illuminated warning light
  • Harsh, erratic, or unpredictable gear shifts
  • Varying degrees of transmission slippage under certain driving conditions
  • Gear selection may be delayed
  • Transmission overheating
  • Increased fuel consumption

Common Causes

  • Damaged, burnt, shorted, disconnected, or corroded wiring and connectors
  • Defective pressure control solenoid B
  • Dirty, contaminated, or degraded transmission fluid
  • Clogged fluid passages
  • Dirty or clogged fluid filter
  • Defective valve body
  • Defective pressure pump

Diagnosis

  1. Record all fault codes present, as well as freeze frame data.
  2. Identify and locate pressure control solenoid B and its related wiring.
  3. Perform a thorough visual inspection of all related wiring for damage or corrosion.
  4. Check resistance, ground, continuity, and reference voltage on all related wiring.
  5. Test the internal resistance of pressure control solenoid B.

Fixes

  • Replace damaged wiring and connectors as needed.
  • Replace defective pressure control solenoid B if necessary.

FAQ

What does P0778 mean?

P0778 indicates an electrical malfunction with the pressure control solenoid B in the transmission.

How do I fix P0778?

Fixes include replacing damaged wiring and connectors, or replacing a defective pressure control solenoid B if necessary.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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