P0740 Code Definition
Torque converter clutch circuit malfunction is the technical definition of this trouble code
What the P0740 code means
What the P0740 code means is that the powertrain control module (PCM) has detected something unusual within the torque converter clutch circuit. The powertrain control module can vary the application of the torque converter clutch for optimal vehicle performance. If the torque converter clutch application is abnormal (usually multiple times) the powertrain control module will trigger a Check Engine Light.
What are the causes of the P0740 code?
Some potential causes of the P0740 code may include:
- A faulty torque converter clutch solenoid
- A damaged torque converter or clutch
- Incorrect transmission fluid level
- Skipping over transmission maintenance
- A restriction within the transmission
- Internal transmission damage
- A faulty powertrain control module or transmission module
What are the symptoms of the P0740 code?
Symptoms of a P0740 code that the driver may experience would include:
- The transmission not shifting in or out of a particular gear
- The transmission may shift harshly
- The torque converter clutch may not engage or disengage causing the vehicle not to move
- The engine may stall
- The transmission could overheat
How does a mechanic diagnose the P0740 code?
A mechanic may begin the diagnosis of the P0740 code by first checking the transmission fluid for proper level and condition. If anything is out of the ordinary, this could be part of the problem. If nothing is wrong with the transmission fluid, the mechanic would then use service information to look up a diagnostic procedure for this code given by the manufacturer and then follow the instructions given. Keep in mind that this diagnostic may require the transmission to be removed or even disassembled.
Common mistakes when diagnosing the P0740 code
An easy mistake that could be made is assuming that the torque converter is damaged just because this part is listed in the trouble code. This may result in a lot of money being spent to have it replaced, when it may just be the fluid level needing to be topped off. It is important to look at every aspect of each problem to get to the correct solution as quickly and efficiently as possible.
How serious is the P0740 code?
The P0740 code can be very serious as it can cause drivability issues. This is one of the codes that can leave a driver stranded on the side of the road. A good running engine means nothing without a properly operating transmission to transfer the engine power to the wheels. It is a good idea to have this issue diagnosed and repaired as soon as possible.
What repairs can fix the P0740 code?
Repairs that can fix the P0740 code may include:
- Replacing the torque converter clutch solenoid
- Replacing the torque converter or clutch
- Adding or replacing transmission fluid and filter
- Replacing the powertrain control module
- Overhauling the current transmission
- Replacing the transmission with a brand new one
Additional comments regarding the P0740 code
In order to help prevent trouble codes such as the P0740 code, it is a good idea to replace the transmission fluid in your vehicle along with the filter (if applicable) at the recommended intervals. Doing this will ensure that the internal parts of the transmission stay well lubricated and also prevents debris from causing a restriction within the transmission.
Need help with a P0740 code?
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.