P0748 Code: Pressure Control Solenoid “A” Electrical

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Electronically controlled automatic transmissions have a pressure control solenoid that controls the transmission’s hydraulic pressure. needed to make the transmission operate properly. If your powertrain control module (PCM) detects problems in your pressure control solenoids, it may trigger trouble codes, including code P0748.

If a P0748 code pops up after using a scan tool, you need to get your vehicle fixed soon to avoid additional issues. Here’s what you need to know about the P0748 code:

What Does the P0748 Code Mean?

Diagnostic trouble code (DTC) P0748 stands for “Pressure Control Solenoid ‘A’ Electrical.” This code is generally set by your PCM if it detects complications in the pressure control solenoid that is designated “A.” The electronic automatic transmission’s pressure control solenoid(s) regulate transmission hydraulic pressure in response to throttle angle, engine speed, and prevailing load requirements.

For example, if you’re pulling a trailer up a hill, the ECM/PCM will increase transmission line pressure to hold the gears longer and provide a firmer shift, because that’s what’s needed under those circumstances. If you aggressively accelerate even on flat pavement, the same command is delivered.

Transmission line pressure determines shift timing and quality and if the electrical circuit controlling the Pressure Control Solenoid fails the line pressure will default to maximum. The transmission will usually shift much firmer and it may also shift later, depending on the platform. The firm shift protects the clutches to prevent them from burning out, which happens if they’re not firmly applied and the transmission is providing torque to the output.

“Electrical” indicates that this is a problem with the circuit rather than the mechanical part of the solenoid itself, although the solenoid winding may be the cause of the fault code.

Note: The definition of code P0748 may be different depending on the vehicle manufacturer. Consult the appropriate repair manual or repair database for the exact code definition.

What are the Possible Causes of the P0748 Code?

A P0748 code can be triggered by various vehicle problems. Here are this trouble code’s most common causes:

• Defective or faulty pressure control solenoid
• Dirty transmission filter and/or fluid
• Faulty transmission pump and/or valve body
• Clogged hydraulic channels
• Wiring or connector damage
• PCM malfunction or damage

What are the Common Symptoms of the P0748 Code?

Trouble codes can be accompanied by different symptoms. They can change depending on what is causing the P0748 code. Here are the most common symptoms of a P0748 code:

• Illuminated check engine light
• Erratic shifting
• Poor fuel economy
• Overheating transmission

How to Diagnose the P0748 Code

Like all trouble codes, P0748 can become difficult to diagnose. Diagnosis and troubleshooting can also vary, depending on your vehicle’s make and model. Consulting a professional is the quickest way to fix issues causing your vehicle’s P0748 code. However, you can get a good idea of how to diagnose this trouble code by watching this video:

How to Fix the P0748 Code

Problems that cause trouble codes may not be a big deal at first. However, they can become severe over time. You can try working on a P0748 code from home, but fixing trouble codes can be too technical for a DIYer. Asking a mechanic for help is the fastest way to fix the P0748 code.

You can get an understanding of the P0748 code by doing some research. First, you can determine what’s causing the code and the complications related to it. Once you have all the information, you need to check a reliable repair manual or online repair database to work out the correct course of action.

It is also a good idea to have your vehicle’s repair manual on hand. Some fixes that work on other vehicles may not work for yours. What applies for a P0748 code in a Dodge may not apply for a Ford. Tread carefully as you try to resolve your vehicle’s problems. If it becomes too difficult to do on your own, don’t think twice about asking a mechanic for help.