How to Fix P1740 Code On Cummins? (Completely Explained)

DTCs (Diagnostic Trouble Codes) are identifiers for problems that a vehicle exhibits. Knowing these codes properly and understanding them accurately helps solve those issues quickly. But do you know what the P1740 code means on Cummins?

The code P1740 On Cummins indicates undesired RPM drop obtained by the engine torque converter clutch in overdrive. Short transmission fluid level, dirty transmission fluid, broken TCC and OD, and a weak connection between the TCC and OD are the reasons behind this code.

The symptoms of code P1740 are tough to detect. But it becomes easy to solve the code once you’ve found the reasons.

P1740 Code On Cummins

What Is Code P1740 On Cummins?

P1740 is a significant DTC code. It means the engine torque converter clutch failed to decrease the RPM. You’ll clearly understand the code if it is broken into small fractions.

  • P = Powertrain, parts of the structure to move the car onward. (in this case, the torque converter clutch)
  • 1 = Fuel and air metering index according to SAE
  • 7 = Transmission of fluid
  • 40 = Particular fault index (in this case, a faulty overdrive solenoid and the torque converter clutch)

Pray that this code never appears while driving. A car with an imbalanced RPM is dangerous for you and other vehicles on the road.

How Serious Is Code P1740 On Cummins?

It becomes a serious problem when the code P1740 appears on your car’s dashboard. The power Control Module monitors everything related to the power supply in a car.

When your car can’t obtain the required RPM, things turn into worse conditions. The car’s wheels won’t grip properly, resulting in a severe accident. Internal engine parts start to erode before the appearance of this code.

A faulty engine torque converter can’t minimize the RPM level, which also hampers the performance of the PCM. You’ll have a bumpy and uncontrolled ride when the code P1740 appears. It also costs a fat sum to fix the code.

When this code pops on the dashboard, the car is not only dangerous for you but also for the vehicles on the street!

What Causes P1740 Code On Cummins?

The code P1740 occurs because of some critical reasons. But some causes are visible if you concentrate a little.

Here are the valid reasons behind the P1740 code on Cummins.

  • Short Transmission Fluid Level

A significant decrease in the transmission fluid is the common reason behind the P1740 code. Sometimes this code appears on the car’s dashboard because of the leaking of the transmission fluid.

  • Greasy Transmission Fluid

Transmission fluid delivers hydraulic pressure and friction to operate the car’s internal parts. But dirty transmission fluid can’t provide maximum friction. So, the code appears to notify the driver.

  • Defective Torque Converter Clutch (TCC) And Overdrive Solenoid (OD)

A defective TCC and OD can’t work together. They won’t be able to achieve the required torque while cornering or drifting.

  • Weak Electric Connection Of TCC and OD

If the connection between the TCC and OD isn’t substantial, it fails to send a solid signal to drop the RPM. This is one of the reasons behind the P1740 code.

How To Fix Cummins P1740 Code?

Fixing the pop-up code P1740 early will save you in the long run. Taking an expert’s help is the best solution. You can DIY it in your home if you follow this method.

Level The Transmission Fluid:

Fix the leakages in the transmission tube to stable the fluid level. Change the oil regularly for better performance and torque.

Fix The Broken TCC and OD:

Restoring a broken TCC and OD is pretty tough. Replacing these parts is the best solution. New TCC and OD will provide maximum output.

Replace Faulty Connector’s Pins:

You can find these pins with bare eyes. Replace the bent, corroded, and broken connector pins with new ones.

Other Symptoms Of Getting P1740 Code On Cummins

Some additional signs will tell you about the P1740 code on Cummins. These symptoms get mixed with other DTC code signs. So, check thoroughly for the P1740 code.

A Running Engine Light

Running engine light is a common sign for the P1740 code. Take a proper visual before you mix it up with other code signs. Keep an eye on the car’s control panel to observe the engine light.

Warning Light Of Service Engine

Another symptom of code P1740 is the warning light of the service engine. It identifies the imbalanced RPM of the car through the Power Control Module (PCM).

How Much Does It Cost To Fix Cummins P1740 Code?

The location of the repair shop, the vehicle’s structure, engine type, and car model are some of the crucial determiners of the fixing price. You must consider these factors before you set the code right.

The average price is between $75 to $150 in most mechanic shops. It’ll cost you more money if the mechanic shop is far from your place.

Some automotive repair shops charge differently for scanning the code and fixing it. Then comes the car’s model and structure type.

You’ve to pay more money if you own a branded car because of its complex structure. Don’t forget the engine type and its model. Most repair shops charge on an hourly basis.

Can You Drive With Your Cummins With Code P1740?

It’s the worst idea to drive your car with the code P1740. In fact, stop driving immediately if you’re driving your vehicle with the P1740 code. You shouldn’t even run a test drive with this pop-up code!

The car won’t run swiftly without the desired RPM drop. As a result, car wheels will have different spins that could lead to an accident. You’ll have very little time to solve this problem.

It hampers the engine performance, which is not feasible. The price is high if you can’t achieve the required RPM drop. While taking a turn or drifting, the torque converter will fail to provide maximum force.


Your car has some serious problems if you see the P1740 code on the car’s dashboard. However, it’s elementary to fix if you’ve proper knowledge regarding this code. But taking an expert’s opinion is the best option. 

We hope that the discourse on what the P1740 code means on Cummins has given you a clear view of how to solve the issue.

Look for the symptoms before you fix the code. Do regular maintenance of your car to avoid problems related to the engine torque converter clutch in overdrive.

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