OBD-II Code · Powertrain
P0748
Pressure Control Solenoid "A" Electrical
Severity
high
Left alone, this one tends to take other parts with it.
Can you drive it
Not for long
Driving on this one risks further damage. Get it to a shop rather than carrying on with it.
Indicative cost (USD)
$300–$2,500
Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
EPC solenoid electrical fault — controls main line pressure.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then work the likely-causes list in the order shown.
That order is what a shop checks first for this code — wiring and connections before the component they run to, because a connector costs nothing to inspect and is a common answer.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Harsh shifts
- Slipping
- Possible no-engagement
Likely causes
- Failed EPC solenoidMost common
- Wiring
- Contaminated trans fluid
Read the full diagnostic procedureP0748 is the electrical version of the pressure control solenoid A fault: the TCM commanded the EPC solenoid and saw an open circuit, short to ground…
P0748 is the electrical version of the pressure control solenoid A fault
the TCM commanded the EPC solenoid and saw an open circuit, short to ground, or short to power on the driver feedback. Cheapest-first ladder: measure solenoid resistance at the case connector against spec (most EPC solenoids run 4-6 ohms); inspect the internal wire harness/pass-through connector for the same fluid migration and pin corrosion failure mode that drives most case-connector faults; verify TCM power and grounds before condemning the module; only then replace the solenoid. Caveat: an intermittent P0748 with no current fault and clean wiring is most often a thermal-sensitive solenoid winding that will only confirm with the unit at full operating temperature on the lift.
Vehicle-specific patterns1996-2003 Ford Taurus and Windstar with the AX4S/AX4N set P0748 from a failed EPC solenoid that is straightforward to replace through the side cover.
- 1996-2003Ford Taurus and Windstar with the AX4S/AX4N set P0748 from a failed EPC solenoid that is straightforward to replace through the side cover.
- 2001-2006GM trucks with the 4L60E set P0748 from internal harness pass-through corrosion at the case connector.
- 2005-2010Chrysler 300/Charger with the 545RFE set P0748 from a failed line pressure (LP) solenoid in the solenoid pack, replaced as a complete pack assembly.
- 2003-2009Saab 9-3 with the Aisin AW55-50SN sets P0748 when the internal harness fails inside the case.
Estimated repair$220 to $1,100.
Look up another code
P0748 — frequently asked
What does a P0748 code mean?
EPC solenoid electrical fault — controls main line pressure.
What causes a P0748 code?
Common causes: Failed EPC solenoid; Wiring; Contaminated trans fluid.
What are the symptoms of a P0748 code?
Typical symptoms: Harsh shifts; Slipping; Possible no-engagement.
Is it safe to drive with a P0748 code?
Not for long. Driving on this one risks further damage. Get it to a shop rather than carrying on with it. Estimated repair: $300-$2,500.
How do I diagnose a P0748 code?
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed. 1. Note every code that is set, not just this one. 2. Read the freeze frame — the conditions the fault was recorded under. 3. Confirm the fault is current rather than history. 4. Then work the likely-causes list in the order shown.
More free tools