P0748Pressure Control Solenoid A Electrical
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Pressure control solenoid A sets line or clutch pressure by current; most are 'normally high', so with no current – as in limp mode – maximum pressure applies. 'A' is usually the line pressure valve, on GM clutch-to-clutch transmissions (6T, 8L, 9T) the pressure valve of clutch 1. Ford does not use P0745–P0749 but P0960–P0963. P0748 is the electrical code of this valve, checked by current, duty cycle or terminal voltage: Subaru after 0.14 s with MIL after two trips and limp mode in third, Allison against an 8 Ω current model after 125 ms, GM's diesel 4L80-E for a duty cycle outside 0.5–95 % for 2 s without MIL. The valve is switched off – maximum pressure, harsh shifts, frozen adaption, often a fixed gear (Saab AF40: second and reverse) and reduced torque. Saab's 2010 9-5 uses P0748 for a current deviation instead.
- What you may notice
- Harsh shifts or engagement (maximum pressure)
- Limp mode in a fixed gear
- Transmission warning or check engine light
- Reduced engine power (torque limit)
- Likely causes
- LikelyHarness or transmission connector (corrosion, oil, chafing)
- LikelyPressure control solenoid faulty (resistance out of spec)
- PossibleInternal harness, electronic module or mechatronic unit
- RareSystem voltage too low
- RareTransmission module driver
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €150 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.