P0719
Brake Switch B Circuit Low
Transmission / brake switch input
Generic OBD-II
High
What it means
P0719 means the transmission controller sees a constantly low signal from brake switch B — the input that tells it whether the brake pedal is pressed. The controller uses this to release the torque converter clutch and manage cruise control, so a faulty switch or wiring can cause lockup shudder, cruise dropouts, and brake-light issues.
High
Can I keep driving? Usually drivable, but the torque converter may not lock up smoothly and cruise control may cut out. Get the brake switch checked soon.
Common symptoms
What you'll notice
- Check-engine light on
- Torque converter clutch not locking/unlocking smoothly (shudder or flare)
- Cruise control won't engage or drops out
- Brake lights possibly stuck on or not working
Common causes
Most likely first
- Faulty brake light switch (brake switch B)Likely
- Short-to-ground or open in the brake switch wiringCommon
- Corroded or loose brake switch connectorCommon
- Blown fuse in the circuitLess often
- Failed transmission control module (least common)Less often
How to diagnose & fix
Work through it in order
- Scan and confirm the brake switch signal changes when the pedal is pressed.
- Check that the brake lights work and the switch is adjusted correctly at the pedal.
- Inspect the brake switch wiring and connector for a short to ground or an open.
- Check the relevant fuse.
- Replace or re-adjust the brake switch as needed. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0719?+
Generally yes, but the transmission's torque converter lockup and the cruise control rely on this signal, so they may behave oddly. Also verify your brake lights work correctly.
Can I just clear P0719?+
It returns until the brake switch or its wiring is fixed. Since the same switch often runs your brake lights, it's worth repairing properly.
Related codes
Often seen with P0719
Read & clear P0719 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