P07B8
Transmission Park Position Sensor/Switch B Circuit/Open
Transmission
Generic OBD-II
Medium
What it means
P07B8 means an open circuit is detected in the "B" circuit of the transmission park position sensor/switch. This switch tells the vehicle when the selector is in Park, and it feeds the start interlock and gear-position display. An open can cause a wrong gear readout or prevent the engine from starting in Park, usually from a faulty switch, open wiring, or a corroded connector.
Medium
Can I keep driving? Possibly, but the vehicle may not start in Park and the gear readout can be wrong; get it checked promptly.
Common symptoms
What you'll notice
- Gear-position indicator wrong or missing
- May not start in Park (or only starts in Neutral)
- Shift interlock or start-interlock behaves incorrectly
- Check-engine or transmission warning light on
Common causes
Most likely first
- Faulty transmission park position sensor/switchLikely
- Open or damaged wiring or connectorCommon
- Corrosion in the sensor connectorCommon
- Misadjusted shift linkage or switchLess often
- Transmission control module fault (less common)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and note any companion range-switch codes.
- Inspect the park position switch connector and wiring for an open or corrosion.
- Verify the switch and shift-linkage adjustment.
- Test switch continuity across the Park and other ranges.
- Replace the park position sensor/switch if it fails testing.
FAQ
Quick answers
Is it safe to drive with P07B8?+
Driving may be possible, but the start interlock relies on this signal, so the car may not start in Park and the gear readout can be wrong. Get it checked promptly.
Can I just clear P07B8?+
An open circuit will set it again immediately. Repair the switch or wiring before clearing.
Related codes
Often seen with P07B8
Read & clear P07B8 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