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P2729 OBD-II Trouble Code: Pressure Control Solenoid E Control Circuit Low

check engine light

P2729 code definition

The P2729 code shows up when there is an abnormality detected in a specific electronic pressure control solenoid or solenoid circuit.

What the P2729 code means

The computer-controlled automatic transmission in your vehicle uses varying amounts of hydraulic pressure to supply torque converter lockup and shift actuation. Electronic pressure control solenoids – which are monitored and controlled by the PCM – are used for regulating pressure. This code appears if the pressure falls outside of the acceptable parameters.

What causes the P2729 code?

There are a number of reasons the pressure could be off and the P2729 is triggered. The most common would be:

  • A malfunctioning electronic pressure control solenoid is causing the code to show up even though the pressure is actually fine.

  • There are hydraulic blockages occurring inside the internal transmission fluid passages which are causing the pressure to build.

  • Mechanical transmission failures.

  • Low levels of transmission fluid.

  • Contaminated transmission fluid.

  • A malfunctioning transmission control module or PCM.

What are the symptoms of the P2729 code?

One of the tough things about determining the underlying problem behind a P2729 code is that there may actually be no noticeable symptoms except for a possible Check Engine Light. On the other hand, the issue could be extremely apparent if it manifests itself through symptoms like disabled shifting or the torque converter clutch refusing to engage or disengage.

Sometimes, the code will coincide with the PCM putting the transmission into “limp-home” mode. Harsh shifting, transmission overheating, transmission slippage, a stored code, decreased fuel efficiency and a malfunction indicator lamp are other common symptoms to look out for. This code is also accompanied by lock up, torque converter clutch, shift solenoid, gear ratio and transmission slippage codes.

How does a mechanic diagnose the P2729 code?

To begin with, a mechanic will need to use a code reader or scanner along with a digital ohmmeter/voltmeter to diagnose the P2729 code. Practically every vehicle with an automatic transmission made since the mid-80s has some kind of computer-controlled automatic transmission system. OBD-II-equipped vehicles have a sophisticated computer-controlled system that accounts for various metrics of engine drivability as well.

Once the code is confirmed, the mechanic will most likely move onto checking the transmission pressure to see if it is enough for actuating gear changes. If pressure is low, they’ll assess the transmission fluid to see if it is low or just dirty. Then they’ll inspect the dipstick if necessary.

If there is nothing out of place about the fluid, the wiring and connectors will need to be examined to ensure their structural integrity. In some cases, the entire internal transmission harness has to be replaced.

Common mistakes when diagnosing the P2729 code

The electronic pressure control solenoid is often overlooked. The same can be said for wiring malfunctions. High pressure pumps get unnecessarily replaced a lot too.

How serious is the P2729 code?

Code P2729 can represent a number of different problems, but none of them should be considered minor. Even something like reduced fuel efficiency is nothing you want to deal with for an extended period of time as it’s going to cost you at the pump. Other problems like harsh shifting or your transmission overheating will mean your automobile simply quits working.

What repairs can fix the P2729 code?

While it depends on the exact nature of the problem behind the P2729 code, common repairs include:

  • Replacing the transmission fluid or simply adding more to it
  • Repairing or replacing wires, circuitry and connectors
  • Addressing clogs or debris in the hydraulic passages
  • Replacing a defective pump, malfunctioning shift solenoids or faulty electronic pressure regulators

Additional comments for consideration regarding the P2729 code

You have to be careful about driving too far after initially clearing the P2729 code. There are intermittent problems that could cause this code and which will show up shortly after the initial fix, which means you could end up stranded with an overheated car if you don’t try a shorter test drive first to see if the code comes back.

Need help with a P2729 code?

At YourMechanic, our goal is to get your vehicle repaired and running as quickly as possible. Call us at 1-800-701-6230 to speak with one of our service advisors or schedule an appointment online. We’ll give you a free quote and send out a certified mechanic to your home or business.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
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