01 P0065, P0066, and P0067: Air Assisted Injector Control • 02 Unlocking the Hidden Features of Modern Automatic Transmiss… • 03 How to choose the best engine oil for your car • 04 P0420 Code Explained: Catalyst System Efficiency Below Thre… • 05 Brakes: The Complete Guide to Troubleshooting Sticking Brak… • 06 At What Mileage Do Most Cars Start Having Issues? • 07 Toyota Hiace Petrol Engine Options 1TR and 2TR: A Comprehen… • 08 Piston Rings: The Key to a Long and Healthy Engine Life • 09 Car Owners Shocked To Discover The Real Purpose Of The Arro… • 10 A Comprehensive Guide to EGR: Function, Faults, and Fixes •

DTC codes / P07xx · Transmission / P0719

P0719Brake Switch 'B' Circuit Low

P0719 means the transmission control module (TCM) sees the brake switch 'B' circuit voltage staying low when it should be switching between high and low states as you press and release the brake pedal. The TCM uses this signal to coordinate torque converter clutch release and shift scheduling during braking, so a stuck-low circuit makes the computer distrust the brake input.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaTransmission

Symptoms you may notice

  • The check engine light or transmission warning light illuminates steadily while driving.
  • Often no symptoms besides the warning light, with normal shifting and braking feel.
  • Harsh or delayed downshifts when slowing to a stop, especially the torque converter clutch staying engaged too long.
  • The engine may stumble or nearly stall when coming to a halt because the converter clutch is not released on time.
  • Cruise control may refuse to engage or may drop out unexpectedly when the brake pedal is touched.
  • On some vehicles the shifter may not release from Park, or the brake lights may behave erratically.

Common causes, most likely first

  1. A failed or sticking brake pedal position switch, where the 'B' contact stays closed or the internal contacts are contaminated.
  2. A misadjusted brake switch bracket or pedal stop pad, so the switch never reaches its released state.
  3. A chafed, pinched or corroded wire in the brake switch 'B' signal circuit shorting to ground.
  4. Water intrusion or corrosion at the switch connector or in a body harness splice feeding the TCM.
  5. A faulty TCM or a poor ground at the TCM connector causing it to misread the brake signal.
  6. An aftermarket brake controller, remote start or alarm tapped into the brake wire and loading the circuit low.

How to diagnose and fix it

  1. Verify the brake lights work normally and check for any stored codes in the body control module (BCM) and TCM before touching anything.
  2. Inspect the brake pedal switch mounting, the pedal stop pad and the switch adjustment, then confirm the switch clicks and releases fully.
  3. Backprobe the brake switch 'B' signal wire at the switch and at the TCM while an assistant presses and releases the pedal, looking for the voltage to toggle between low and high.
  4. Disconnect the switch and check the 'B' circuit for continuity to ground with the pedal released; a short to ground points to a harness fault.
  5. Inspect the harness along the pedal box, kick panel and any body splice for chafe, corrosion or aftermarket taps, and repair as needed.
  6. If the circuit tests good but the TCM still reports low, substitute a known-good brake switch and recheck live data before condemning the TCM.
  7. Clear the codes and perform a road test with live brake switch data displayed to confirm the signal toggles and the code does not return.

Why the brake switch code fools technicians

  • The 'B' circuit is often a separate contact inside the same brake switch assembly, so the brake lights can work perfectly while the TCM still sees a stuck-low signal.
  • A missing or collapsed rubber pedal stop pad lets the switch plunger travel too far, and this mechanical failure mimics a failed switch more often than the switch itself does.
  • Aftermarket accessories tapped into the brake wire, such as trailer brake controllers or remote starters, are a common hidden cause of a low brake signal that only appears with the accessory installed.
  • P0719 does not always mean the switch is bad; a short to ground anywhere in the signal wire, including a body harness splice, will set the same code.
  • On some platforms the brake signal is shared with the cruise control and shifter interlock, so a fault here can disable cruise control or prevent shifting out of Park without any transmission symptom.

Can I keep driving with P0719?

The vehicle is generally safe to drive to a repair shop because the fault affects transmission scheduling and cruise control rather than the brakes themselves, but avoid heavy towing or aggressive driving and do not rely on cruise control until it is fixed.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage