Corroded or damaged connector, or faulty or damaged wiring to the solenoid (both sources). Defective pressure control solenoid (both sources). Dirty or contaminated transmission fluid that restricts hydraulic passages (both sources). Defective transmission valve body (both sources). Dirty or clogged transmission filter, or a defective transmission pump (OBD-Codes.com). Faulty PCM (OBD-Codes.com).

Clean corrosion from connectors and repair or replace damaged wiring. Replace the faulty pressure control solenoid (both sources list solenoid failure). Change the transmission fluid and filter, or flush the transmission to clean passages (OBD-Codes.com). Repair or replace the valve body, or the transmission pump, if testing points there. Flash (reprogram) or replace the PCM if it is confirmed faulty (OBD-Codes.com).

P0748🔧 Automatic transmission (pressure control)Stop and fix promptly

P0748: Pressure Control Solenoid A Electrical (Meaning, Causes, Fixes)

Q: What does P0748 mean?

P0748 means the computer that runs the automatic transmission has found an electrical problem with pressure control solenoid A, the valve that sets the fluid pressure used to shift gears. Wiring or connector trouble and a failed solenoid are the usual suspects, though both sources also list dirty fluid and the valve body, and left alone it can lead to slipping and further transmission damage. Automatic transmissions change gears by applying clutches and bands with hydraulic fluid pressure. Pressure control solenoids, usually at least an A, B and C, regulate that pressure. OBD-Codes.com says the powertrain control module (PCM) sets P0748 when pressure control solenoid A is experiencing an electrical malfunction, and that the other solenoid A codes are P0745, P0746, P0747 and P0749, each set for a different specific fault. RepairPal's detailed explanation says P0748 means the PCM is not seeing the specified electrical voltage drops from the pressure control solenoid as it works, which matches the electrical description. RepairPal's short summary, though, uses the same generic wording it uses for P0745 to P0747: the transmission control module (TCM) sets the code when a pressure control solenoid is not performing as desired. The two sources name a different module because some vehicles control the transmission from the PCM and others from a separate TCM; it's the same fault. RepairPal's definition line also drops the letter ("Pressure Control Solenoid Electrical"), while its headline and OBD-Codes.com both say solenoid A. Even though the code points to an electrical fault, OBD-Codes.com's cause list still includes hydraulic items like dirty fluid, a clogged filter, the pump and the valve body. This is a generic code for vehicles with automatic transmissions, and OBD-Codes.com lists Ford, Mercury, Lincoln, Jaguar, Chevrolet, Toyota, Nissan, Allison/Duramax, Dodge, Jeep, Honda and Acura among them, but notes exact repair steps vary by year, make, model and powertrain.

Q: Can I keep driving with P0748?

Stop and fix promptly. Get it fixed soon and drive gently until you do. Sources differ on how serious it is: RepairPal rates P0748 Urgent, meaning immediate action is needed because it can cause severe damage, while OBD-Codes.com says it normally starts as moderate but can progress to a more severe level rapidly if not corrected in a timely manner. RepairPal adds that the vehicle may not be driveable. If the transmission slips, overheats, shifts harshly or drops into limp mode, avoid highway driving and towing and get it to a shop before more damage is done.

Reviewed 2026-10-25 · Based on 2 cited source(s)

What P0748 means

Automatic transmissions change gears by applying clutches and bands with hydraulic fluid pressure. Pressure control solenoids, usually at least an A, B and C, regulate that pressure. OBD-Codes.com says the powertrain control module (PCM) sets P0748 when pressure control solenoid A is experiencing an electrical malfunction, and that the other solenoid A codes are P0745, P0746, P0747 and P0749, each set for a different specific fault. RepairPal's detailed explanation says P0748 means the PCM is not seeing the specified electrical voltage drops from the pressure control solenoid as it works, which matches the electrical description. RepairPal's short summary, though, uses the same generic wording it uses for P0745 to P0747: the transmission control module (TCM) sets the code when a pressure control solenoid is not performing as desired. The two sources name a different module because some vehicles control the transmission from the PCM and others from a separate TCM; it's the same fault. RepairPal's definition line also drops the letter ("Pressure Control Solenoid Electrical"), while its headline and OBD-Codes.com both say solenoid A. Even though the code points to an electrical fault, OBD-Codes.com's cause list still includes hydraulic items like dirty fluid, a clogged filter, the pump and the valve body. This is a generic code for vehicles with automatic transmissions, and OBD-Codes.com lists Ford, Mercury, Lincoln, Jaguar, Chevrolet, Toyota, Nissan, Allison/Duramax, Dodge, Jeep, Honda and Acura among them, but notes exact repair steps vary by year, make, model and powertrain.

Severity: can I keep driving?

Stop and fix promptly

Get it fixed soon and drive gently until you do. Sources differ on how serious it is: RepairPal rates P0748 Urgent, meaning immediate action is needed because it can cause severe damage, while OBD-Codes.com says it normally starts as moderate but can progress to a more severe level rapidly if not corrected in a timely manner. RepairPal adds that the vehicle may not be driveable. If the transmission slips, overheats, shifts harshly or drops into limp mode, avoid highway driving and towing and get it to a shop before more damage is done.

Common symptoms

Check engine light on (both sources)
Transmission slips when shifting or won't shift from gear to gear properly (both sources)
Vehicle enters limp mode (OBD-Codes.com) or may not be driveable (RepairPal)
Transmission overheating (OBD-Codes.com)
Transmission catches in gear (OBD-Codes.com)
Decreased fuel economy (both sources)
Possibly misfire-like symptoms (OBD-Codes.com) or other performance problems (RepairPal)
In unusual cases, no problems noticed by the driver (RepairPal)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Corroded or damaged connector, or faulty or damaged wiring to the solenoid (both sources)
Defective pressure control solenoid (both sources)
Dirty or contaminated transmission fluid that restricts hydraulic passages (both sources)
Defective transmission valve body (both sources)
Dirty or clogged transmission filter, or a defective transmission pump (OBD-Codes.com)
Faulty PCM (OBD-Codes.com)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Visually inspect the wiring and connectors to the transmission, the pressure control solenoids, the transmission pump and the PCM for damage, corrosion, loose connections or damaged pins. Since this is an electrical code, this is the best place to start.
Check the transmission fluid level and look at its condition, following your owner's manual procedure. RepairPal says healthy fluid is a clear cranberry color, while dirty, brown or burnt fluid points to trouble.
Find out when the transmission fluid and filter were last changed. OBD-Codes.com recommends checking service records before changing the fluid.
Read all stored codes. Both sources list engine misfire and driveline problems as possible misdiagnoses, and OBD-Codes.com adds transmission pump and internal transmission problems, so other codes can point you in the right direction.

Typical fixes

Clean corrosion from connectors and repair or replace damaged wiring
Replace the faulty pressure control solenoid (both sources list solenoid failure)
Change the transmission fluid and filter, or flush the transmission to clean passages (OBD-Codes.com)
Repair or replace the valve body, or the transmission pump, if testing points there
Flash (reprogram) or replace the PCM if it is confirmed faulty (OBD-Codes.com)

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

The transmission is slipping, overheating, catching in gear, stuck in limp mode or won't drive
RepairPal's shop procedure records freeze frame data, test drives at that road speed while watching the solenoid's commanded duty cycle on a scan tool, then does voltage drop and continuity tests by back-probing the harness
Continuity checks should read 0 ohms unless the service data says otherwise and must be done with power removed from the circuit (OBD-Codes.com); this needs a digital multimeter and vehicle-specific specifications
OBD-Codes.com recommends checking technical service bulletins (TSBs) for your year, model and transmission first, which a dealer or shop can look up

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I drive with P0748?

Only gently and briefly. RepairPal rates it Urgent and says the vehicle may not be driveable, and OBD-Codes.com says it can go from moderate to severe rapidly if not corrected, so get it diagnosed before the transmission is damaged further.

Is P0748 always a bad solenoid?

No. It's an electrical code, so wiring and connectors are a common cause, and both sources also list dirty fluid and the valve body. OBD-Codes.com adds a clogged filter, the transmission pump and the PCM. Check wiring and fluid before buying a solenoid.

What's the difference between P0745, P0747 and P0748?

All three are about pressure control solenoid A. OBD-Codes.com describes P0745 as a general malfunction, P0747 as the solenoid stuck on and P0748 as an electrical malfunction.

How much does it cost to fix P0748?

Neither source gives a repair cost. It ranges widely depending on whether the fix is wiring, the solenoid, a fluid service, the valve body or the pump, so get a diagnosis and written estimate first.

Sources

Last reviewed 2026-10-25. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.