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?

No — this code can cause damage if you keep driving. Get it diagnosed before continuing. Estimated repair: $300-$2,500.

OBD-II Code · Powertrain

P0748

Pressure Control Solenoid "A" Electrical

high severityDo not drive$300-$2,500

EPC solenoid electrical fault — controls main line pressure.

Common symptoms

Harsh shifts
Slipping
Possible no-engagement

Likely causes

Failed EPC solenoid
Wiring
Contaminated trans fluid

Where to start

Try the cheapest cause first. Start by checking: failed epc solenoid.
Cost & scope. $300-$2,500
If the code returns after the fix: escalate to a shop or scanner with live-data and freeze-frame. A code that re-sets means the underlying fault is still there. Don't keep driving with this one active — risk of damage.

Read the full diagnostic procedure+

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 patterns+

Vehicle-specific patterns: 1996-2003 Ford Taurus and Windstar with the AX4S/AX4N set P0748 from a failed EPC solenoid that is straightforward to replace through the side cover. 2001-2006 GM trucks with the 4L60E set P0748 from internal harness pass-through corrosion at the case connector. 2005-2010 Chrysler 300/Charger with the 545RFE set P0748 from a failed line pressure (LP) solenoid in the solenoid pack, replaced as a complete pack assembly. 2003-2009 Saab 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

← All OBD-II codes

More free tools

VIN DecoderDecode year, make, model, engine, recalls.Maintenance ScheduleOil, timing belt, fluids, by vehicle.Gas CostWeekly, monthly, annual fuel math.Tire SizeOEM vs new — diameter delta + speedo error.

See all 10 tools