P0764 indicates an intermittent electrical fault within the shift solenoid C circuit of an automatic transmission. This solenoid controls hydraulic flow to engage specific gears, and the powertrain control module has detected irregular voltage or resistance. The issue often stems from electrical connectivity rather than a complete component failure.
Internal coil wear or sticking plunger causes intermittent electrical contact.
Heat or vibration causes wires to chafe, short, or lose connection temporarily.
Corrosion or looseness at the transmission connector disrupts signal flow.
Dirty fluid affects solenoid operation and hydraulic pressure stability.
Debris or wear inside the valve body restricts solenoid movement.
Internal driver circuit failure is rare compared to external components.
It is not recommended as intermittent shifting issues can lead to further transmission damage or unsafe driving conditions.
No, this usually indicates an electrical or solenoid issue that can often be repaired without replacing the entire transmission.
No, PCM failure is extremely rare for this code; replacing the computer is usually unnecessary and should only be considered after all wiring and solenoid tests pass.
It may help if the fluid is low or dirty, but it will not fix a failed electrical solenoid or damaged wiring.