P0748 code meaning
Pressure Control Solenoid A Electrical
Powertrain system Generic code P07xx codes Check engine light
What P0748 means
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.
P0748 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0748
- Harsh shifts or engagement (maximum pressure)
- Limp mode in a fixed gear
- Transmission warning or check engine light
- Reduced engine power (torque limit)
Common causes of P0748
- Most likelyHarness or transmission connector (corrosion, oil, chafing)
- Most likelyPressure control solenoid faulty (resistance out of spec)
- PossibleInternal harness, electronic module or mechatronic unit
- Less likelySystem voltage too low
- Less likelyTransmission module driver
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pressure control solenoid aTransmission valve bodyTransmission wiringTransmission control module
What each part of P0748 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 7 | Area: transmission. |
| 48 | The exact fault in that area. |
What to do next
- Note P0748 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0748
What does P0748 mean?
P0748 means "Pressure Control Solenoid A Electrical". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P0748?
Drive gently and only to a workshop. With P0748 the car can go into limp mode (reduced power) to protect itself.
Will P0748 fail an emissions test?
Yes, it can. P0748 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0748 to fix?
Difficulty: medium. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P0748 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.