Transmission Fluid Pressure Sensor/Switch B Circuit High
What it means
P0848 means the transmission controller sees an abnormally high voltage on the fluid pressure sensor/switch "B" circuit, usually from an open or a short-to-power in the wiring. The engine starts and runs, but with a bad pressure signal the transmission may shift irregularly or drop into a protective limp mode until the circuit is repaired.
Can I keep driving? The engine runs, but shifts may be harsh, delayed, or the transmission may enter limp mode — have it diagnosed before hauling or long trips.
Real-world scan data
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
Common symptoms
What you'll notice
- Check-engine light on
- Harsh or delayed shifting
- Irregular shifting or transmission stuck in a fail-safe gear
- Reduced fuel efficiency
Common causes
Most likely first
- Faulty transmission fluid pressure sensor/switch (B)Likely
- Open circuit or short-to-power in the sensor wiringCommon
- Loose or corroded connector at the sensorCommon
- Failed control module (rare — check wiring first)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and note when the high reading occurs.
- Inspect the pressure sensor connector and wiring for opens, shorts, or corrosion.
- Compare the sensor's reported pressure to actual line pressure with a scan tool/gauge.
- Repair wiring/connector faults, then replace the pressure sensor/switch if it still reads high. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0848?+
Can I just clear P0848?+
Related codes
Read & clear P0848 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.