P071D
Transmission Mode Switch B Circuit
Transmission controls
Generic OBD-II
High
What it means
P071D means the computer has detected a fault in the "B" circuit of the transmission mode switch — the control that selects driving modes such as normal, sport, or tow/haul. It's a comfort/convenience fault: the car drives normally, but the selectable mode may be stuck in its default program until the switch circuit is repaired.
High
Can I keep driving? The car drives normally — only the selectable drive mode (e.g. sport/tow/normal) may not work, so you can keep driving and fix it at your convenience.
Common symptoms
What you'll notice
- Selectable drive mode (sport/tow/economy) won't change or is ignored
- Transmission stays in its default shift program
- Check-engine light on
- Mode indicator light not responding
Common causes
Most likely first
- Faulty transmission mode switchLikely
- Open or short in the mode switch wiringCommon
- Corroded connector or liquid intrusion at the switchCommon
- Faulty TCM/PCM (less common)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm which mode switch circuit is flagged.
- Visually inspect the mode switch for corrosion or liquid intrusion.
- Check the switch wiring and connectors for opens and shorts.
- Test the switch signal as you toggle modes with a scan tool.
- Repair or replace the switch, clear the code, and retest.
FAQ
Quick answers
Is it safe to drive with P071D?+
Yes. This only affects the selectable drive mode — normal shifting and safety are unaffected. You just may not be able to switch modes until it's fixed.
Can I just clear P071D?+
It returns once the module re-checks the switch circuit. The switch or its wiring has to be repaired for the code to stay cleared.
Related codes
Often seen with P071D
Read & clear P071D 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