P0740 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.

Definition

This code shows that there is a malfunction with the torque converter clutch circuit. The electrical control unit has detected a problem with the circuit controlling the torque converter clutch solenoid.

The make and model of the vehicle can have an impact on the ways that the diagnostic and repair process should be performed. This means that the specific instructions from the manufacturer of the vehicle may have to be referenced.

Meaning

The P0740 code means that something unusual has been detected by the powertrain control module (PCM) within the torque converter clutch circuit. The application of the torque converter clutch can be varied by the powertrain control module to optimize the performance of the vehicle. Multiple applications of the torque converter clutch is considered abnormal. This will trigger the powertrain control module to illuminate the check engine light on the dashboard.

Causes

There are several causes that can trigger the P0740 OBD-II code to appear. Some of the most common causes include a torque converter clutch solenoid, powertrain control module or transmission module that is faulty. Other causes that are associated with the transmission are an incorrect fluid level, restriction within the transmission, internal damage or skipping over maintenance. Damage to the torque converter or clutch can also be potential causes of the code.

Symptoms

Symptoms of the P0740 code include the transmission being unable to shift in or out of a certain gear, harsh shifting of the transmission, overheating of the transmission, engine stalls and the inability to move because the torque converter clutch is not engaging or disengaging.

Diagnosis

A mechanic will begin the diagnostic process by checking the condition and level of the transmission fluid. If anything seems out of place, this could potentially be the source of the problem. If there is nothing wrong with the transmission fluid, the service information would be used to look for the diagnostic procedure provided by the manufacturer for the specific code, and closely follow all of the instructions. The transmission may need to be removed or disassembled in order to properly diagnose the problem.

Common mistakes

One of the most common mistakes with addressing the P0740 code is to assume that the torque converter has become damaged only because of the part’s listing in the trouble code. This can lead to spending a significant amount of money to replace it, when the problem can be solved by simply topping off the fluid level. Another common mistake is believing that the issue is caused by driveline, engine misfire or internal transmission issues. Looking at every aspect of each problem is important, because it can help find the correct solution quickly and efficiently. A professional mechanic will be aware of these mistakes and try to avoid them.

How serious is this?

The P0740 DTC-II is an incredibly serious code because it can cause issues with the drivability of the vehicle. This is one of the codes that can leave drivers stranded with an inoperable vehicle on the side of the road. An engine that runs well means little when the transmission is unable to operate properly, and transfer power from the engine to the wheels. It is in the best interest of a driver to diagnose and repair the issues associated with code as quickly as possible.

What repairs can fix the code?

There are several repairs that can repair problems associated with the P0740 code. The torque converter clutch solenoid, torque converter or clutch, powertrain control module or transmission may need to be replaced. Replacing or adding more transmission fluid and filter or overhauling the existing transmission could also fix the code.

Related codes

Conclusion

It is important for the safety of the driver to properly diagnose and repair problems associated with the P0740 code as soon as possible. If left untreated, the engine in the vehicle could stall and cause serious drivability issues. Applying the proper diagnosis and repairs can prevent a driver from being stuck on the side of the road with an inoperable vehicle. Hiring a professional mechanic is a great way to ensure that each process will be completed correctly and efficiently.