Pressure Control Solenoid "A" Stuck On

Possible causes

• CommonDebris jamming the solenoid open
• CommonFailed solenoid stuck in the applied position
• CommonSticking valve in the valve body
• PossibleDegraded fluid, varnished internals
• PossibleWiring fault holding the solenoid energised

What you might notice

• Very harsh, banging shifts
• Transmission refusing to shift
• Harsh engagement when selecting drive or reverse
• Limp mode
• Check engine light on

What to check, in order

1. Check the fluid level and condition, and look for debris or clutch material.
2. Check whether the solenoid circuit is being held energised electrically before assuming a mechanical jam - a shorted wire produces the same symptom and is cheaper to fix.
3. Read all codes. Several stuck solenoids at once means contaminated fluid, and cleaning up only one of them will not last.
4. Drop the pan and inspect the filter and magnet if you are going in. What you find there tells you whether the transmission is worth repairing.
5. Very harsh shifts put shock loads through driveline components. Do not drive it like this any longer than necessary.