29-05-2025
P0740: Torque Converter Clutch Circuit Malfunction
What does the P0740 error code mean?
The check engine light diagnostic trouble code P0740 stands for "Torque Converter Clutch Circuit Malfunction/Open Circuit Malfunction." The code is set when there are electrical faults with your car's torque converter clutch solenoid or the solenoid circuit. It can cause check engine lights, shifting issues, stalling, shuddering, higher engine speeds, or even reduced fuel economy. Usually, low or poor-quality transmission fluid, among other transmission issues, is to blame.
Why is this issue important?
The torque converter clutch, or TCC, functions like a coupler. It conveys the mechanical power made by the movement of your car's pistons within the engine to the transmission, which eventually results in the wheels of your car spinning. A broken link in this chain can lead to drive issues, like stalling.
Can I safely drive my car with this error code?
It isn't a good idea to go anywhere unless absolutely necessary with a faulty torque converter clutch. The issue can cause your torque converter transmission to slip or fail to engage properly and potentially overheat the transmission. The increased friction can lead to temperature issues and possible long-term damage. The car may not drive well in any case, as these issues will lead to problems like stalling, bad gas mileage, or hard 'shifts' as the transmission struggles to fully engage and transmit the engine's mechanical energy to the wheels.
Common symptoms of the P0740 error code
The check engine light is illuminated
Poor fuel efficiency
Shifting problems like slipping, hard shifts, or failure to engage gears
Overheating transmission, or a burning smell as a result
Higher rpm or engine speed indicated
How is the P0740 error code diagnosed?
Use an OBD-II scanner to confirm the presence of the P0740 code. Some vehicles may not have a dedicated P0740 code but may throw a similar fault shown as a different code.
to confirm the presence of the P0740 code. Some vehicles may not have a dedicated P0740 code but may throw a similar fault shown as a different code. Inspect transmission fluid : Poor-quality transmission fluid or low transmission fluid can cause the P0740 code
: Poor-quality transmission fluid or low transmission fluid can cause the P0740 code Check wiring and connectors : Examining the transmission's wiring harness for faults related to the solenoid circuit may reveal damage or loose connectors.
: Examining the transmission's wiring harness for faults related to the solenoid circuit may reveal damage or loose connectors. Test the torque converter clutch solenoid: A multimeter tool can be used to check the solenoid's resistance and functionality.
How is the P0740 error code repaired?
Replace the faulty torque converter clutch solenoid.
Repair or replace damaged wiring or connectors in the torque converter clutch circuit.
Flush the transmission fluid if it is dirty or degraded.
More information on OBD-II diagnostic trouble codes
Follow the link below to reach our diagnostic check engine trouble codes catalog:
On-board diagnostics (OBD-II) trouble code directory
