Skip the auto shop - Our mechanics make house calls

P2734 OBD-II Trouble Code: Pressure Control Solenoid E Stuck On

check engine light

P2734 code definition

In P2724 codes, the vehicle’s PCM has detected a problem in a particular solenoid circuit or electronic pressure control solenoid. Computer controlled automatic transmissions use specific degrees of hydraulic pressure for torque converter lockup points and shifting; the PCM controls pressure via one or more electronic pressure control solenoids.

What a P2734 code means

The parameters for a P2734 code may vary greatly between manufacturers and models, but they all rely on calculations from:

  • Throttle position
  • Engine speed
  • Vehicle speed

This data helps determine the degree of pump pressure needed for efficient operation. If fluid pressure doesn’t agree with the fluid pressure needed, a code will be stored and the dashboard malfunction indicator lamp (MIL) will illuminate. In some instances, multiple failure cycles may be needed to illuminate the MIL.

Causes of P2734 code

  • Faulty electronic pressure control solenoid
  • Blockage inside internal transmission fluid passages
  • Mechanical failures of internal transmission parts
  • Low fluid level
  • Dirty or contaminated fluid
  • Faulty transmission control module
  • Faulty PCM

Symptoms of P2734 code

  • Failure to shift
  • Failure of torque converter clutch to engage or disengage
  • Limp-in mode
  • Harsh shifts
  • Slipping transmission
  • Overheating transmission
  • Stored code
  • Illuminated MIL or Check Engine Light

Note that the P2724 code may be accompanied by other codes related to torque converter clutch, lockup, gear ratio, shift solenoid or transmission slippage.

Diagnosing the P2734 code

  • A code reader and digital volt/ohmmeter will be needed. The OBD-II uses a computerized control system to compare engine drivability inputs with vehicle speed, engine/turbine speed and transmission output speed, determining transmission fluid pressure via the pressure control solenoid and pump.

  • Check for dirty, contaminated or burnt transmission fluid, and top off transmission if needed using recommended fluid.

  • Burnt fluid, as always, can be a sign of overheating and catastrophic internal mechanical failure. Drop transmission pan and check for clutch material or shavings. If such debris is found, a total rebuild, fluid flush/replacement and new torque converter are recommended. If no debris, check internal wiring and connectors, looking for shorted or burned wiring.

  • In most cases, shorted or burned wiring or connectors will necessitate full replacement of internal transmission harness.

  • If wiring, connectors and components appear OK, connect the scanner to the diagnostic connector and record all stored trouble codes. This information can be helpful in diagnosing intermittent problems that may have led up to the hard code.

  • Clear codes and operate vehicle to see if code returns. If code doesn’t return, it could be an intermittent problem, which can be tricky to diagnose and may need to be allowed to worsen for a proper diagnosis.

  • After clearing codes, fill the transmission with correct fluid and test drive at normal operating temperature. If codes don’t return, the problem may have been caused by low fluid level/pressure. If the code returns along with slippage or delays in engagement, use a manual pressure gauge to check pump pressure.

  • Find a hydraulic pressure diagram for the vehicle and thread your gauge onto the correct opening on the transmission housing, then compare your readings to manufacturer’s specs. Transmission pump replacement will require you to drop the transmission.

  • If the code returns but the transmission seems to operate normally, look into reference voltage and ground signals for electronic pressure control solenoid, and compare against manufacturer’s specs.

  • Disconnect any related control modules and check for continuity and resistance in reference voltage and ground circuits. Repair/replace system circuits and connectors and retest system. Test any other related circuits and the solenoid itself for resistance and continuity, and compare readings against specs.

  • Repair/replace any circuits, connectors or components that don’t comply with specs.

  • Retest entire system; if all circuits seem intact, connect scanner to the diagnostic connector and see if you can manually activate the pressure control solenoid.

  • If the control solenoid is operating properly and all circuits are within manufacturer’s specs, the problem could be the torque converter, high pressure pump or PCM. If the solenoid fails to engage manually, replace the solenoid and then retest the entire transmission control system.

Additional considerations for P2734 code

Sensor issues can be hard to track down, and often can mean several things. A methodical process-of-elimination method is key, rather than just replacing parts. One thing’s for sure, though – transmission problems only get worse as time and miles go on. A P2724 code and its symptoms mean that you should not keep driving that vehicle. Get it into a shop for qualified diagnosis and repair as soon as possible.

Need help with a P2734 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.

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

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


Post a question and get free advice from our certified mechanics.


More related articles

Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance Related Trouble Codes: P2158: Vehicle Speed Sensor B P2160: Vehicle Speed Sensor B Circuit Low P2161:...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...

Related questions

Q: power shuts down,but will run and drive very slow

For issues like this you should have the system computer scanned and have any codes diagnosed by a mechanic. The cost to have the problem properly diagnosed far out weighs throwing parts at the problem hoping to fix it. The...

Q: my check engine light came on.

Hi - the "high voltage" remark from your parts house person means that the O2 sensor is seeing a steady "rich" mixture coming out of the engine, and responds by generating a 1 volt signal (vs 0 volts for a...

Q: Stalls out when I put in drive p1729

Given your mileage, it is likely the throttle body and idle air controller need cleaning. It is also possible the throttle position sensor (which communicates with the transmission) may also be failing. This would seem more likely since your replacement...