P0747 OBD-II Trouble Code: Pressure Control Solenoid Stuck On

P0747 code definition

The PCM will store the P0747 code when an abnormal reading from the electronic pressure control solenoid, or the related circuit, is detected.

What the P0747 code means

In order to monitor gear shift changes and fluid pressure in the transmission, the PCM relies on data from the pressure control solenoid. If the transmission pressure doesn’t align with the manufacturer’s specifications, it is likely that the gear shift operation will not perform correctly. In this case, the PCM will store the P0747 code.

What causes the P0747 code?

A faulty electronic pressure control solenoid is the most likely cause of this code; however, other causes may include:

• Blocked transmission fluid passages
• Low transmission fluid
• Dirty or contaminated transmission fluid
• Faulty electrical components, such as wiring, connectors, or harnesses, within the circuit
• Internal transmission failures

What are the symptoms of the P0747 code?

Symptoms of the P0747 code might be completely unobservable. However, some vehicle owners may experience:

• Disabled shifting function or harsh shifting
• Torque converter clutch that does not engage or disengage
• Slipping or overheating transmission
• Decreased fuel efficiency
• Illuminated Check Engine lamp

How does a mechanic diagnose the P0747 code?

After an OBD-II scanner detects the P0747 code, a technician will perform a thorough visual inspection of the transmission fluid. If it is low, it should be refilled; if the fluid is dirty, contaminated with debris, or smells like it is burnt, the entire system needs to be flushed, and refilled with clean fluid.

At each step, the mechanic should be sure to clear the code from the PCM and retest the system; if the code does not reappear, it’s likely that the issue has been resolved, and no further repairs will be necessary. After performing this task, the mechanic should inspect all electrical components, repairing or replacing any wiring or connectors as necessary. The technician should then continue diagnosing the pressure control components until the fault is discovered.

Common mistakes when diagnosing the P0747 code

The most common mistake that technicians report with the P0747 code is replacing the high pressure pump, when the solenoid or the electrical wiring are more commonly to blame.

How serious is the P0747 code?

Because this code relates directly to the operation of the shifting function, it is considered a high-priority issue that should be repaired as soon as possible. If the issue behind the P0747 code is not addressed immediately, it can cause major malfunctions.

What repairs can fix the P0747 code?

Addressing a P0747 code detection may include any of the following repairs:

• Replace a faulty electronic pressure control solenoid
• Clear blocked transmission fluid passages
• Refill low or dirty transmission fluid
• Repair or replace faulty electrical components within the circuit
• Correct any internal transmission failures

Need help with a P0747 code?

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