P071F
Transmission Mode Switch B Circuit High
Transmission mode switch
Generic OBD-II
Low
What it means
P071F means the B transmission mode switch circuit is reading high — an open or short to voltage. This switch selects driving modes such as normal or sport, so the fault typically leaves the transmission stuck in a default mode rather than affecting how it shifts or drives, and the car remains safe to operate.
Low
Can I keep driving? Yes — this affects the driving-mode switch (such as normal/sport), not core transmission operation, so the car drives normally, though it may be stuck in one mode.
Common symptoms
What you'll notice
- Unable to change transmission driving modes (e.g. normal/sport/tow)
- Transmission stuck in a default mode
- Check-engine light on
Common causes
Most likely first
- Faulty transmission mode switchLikely
- Mode switch wiring open or shorted to voltageCommon
- Corroded or loose connector at the switchCommon
- Faulty control module inputLess often
How to diagnose & fix
Work through it in order
- Scan and confirm P071F, then read freeze-frame.
- Inspect the mode switch and its connector for corrosion or liquid intrusion.
- Check the switch wiring for opens or shorts to voltage.
- Test the switch operation against specification.
- Replace the mode switch if faulty; check the PCM/TCM input if wiring and switch are good.
FAQ
Quick answers
Is it safe to drive with P071F?+
Yes — only the drive-mode selection is affected, not shifting or safety. The transmission runs in its default mode until repaired.
Can I just clear P071F?+
It returns whenever the module re-reads the mode switch circuit high unless the switch or wiring is fixed.
Related codes
Often seen with P071F
Read & clear P071F yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX