Torque Converter Clutch Circuit Stuck On

Possible causes

• CommonTorque converter clutch solenoid stuck open or jammed by debris
• CommonSticking valve in the valve body
• CommonDebris from internal wear jamming the hydraulic circuit
• PossibleDegraded fluid causing valves to stick
• PossibleWiring fault holding the solenoid energised
• PossibleMechanical failure inside the torque converter

What you might notice

• Engine stalls as the car comes to a stop
• Car shudders and bogs at low speed
• Engine feels like it is lugging in too high a gear
• Stalling at junctions and in traffic
• Check engine light on

What to check, in order

1. Treat stalling in traffic as urgent. When the engine stops, power steering assistance and brake servo assistance go with it, and that happens at exactly the moment you are manoeuvring at a junction.
2. You can usually keep the car moving by selecting neutral as you slow to a stop, but that is a way of getting it home, not a repair.
3. Check the fluid level and condition. Debris in degraded fluid is a common cause of stuck valves.
4. Read all codes. Debris in the hydraulics usually sets more than one solenoid code.
5. Check whether the solenoid circuit is being held energised electrically before assuming a mechanical jam.
6. Look for clutch material in the fluid. Its presence changes this from a solenoid repair into a transmission overhaul.