Transmission

P0719 — Brake Switch B Circuit Low

Severity: medium Drive with care, to a shop

What P0719 means

The engine or transmission control module monitors the brake switch to know when the brake pedal is pressed. That signal is used to release the torque converter clutch when braking and to allow the shifter to leave Park. P0719 sets when the voltage in brake switch circuit B stays abnormally low, as with a short to ground or a faulty switch.

Symptoms

  • Check Engine light on
  • Shudder or jerking when braking to a stop (torque converter clutch not releasing)
  • Shifter stuck in Park (shift interlock problem)
  • Brake lights not working or always on
  • Cruise control not cancelling when braking
  • Engine stalling at a stop

Possible causes

  1. Faulty or misadjusted brake light switch
  2. Signal wire shorted to ground
  3. Wiring harness damaged by the brake pedal bracket
  4. Corroded or damaged switch connector
  5. Blown fuse or bad relay in the brake light circuit
  6. Rarely, a failed engine or transmission control module

How to diagnose

  1. Scan for codes and freeze frame data, and note any brake or cruise control codes
  2. Check whether the brake lights work when pressing and releasing the pedal
  3. Inspect the switch, its position and its clearance at the pedal bracket
  4. Check the connector for corrosion, moisture and loose terminals
  5. Watch the brake switch status on a scan tool while pressing the pedal
  6. Use a multimeter to test power, signal and ground at the switch connector against the wiring diagram
  7. Test the signal wire for a short to ground and inspect the harness near the pedal
  8. Check the brake light fuse and relay

Common fixes

  • Replace or adjust the brake light switch
  • Repair the short and restore the wiring insulation
  • Clean or replace the connector
  • Replace the fuse or relay
  • Diagnose and, if needed, replace or reprogram the control module

Questions and answers

What does P0719 mean?

The control module detected a low signal in brake switch circuit B. The most common causes are a bad switch or a wire shorted to ground.

Can I drive with P0719?

Briefly, yes, but you may get shuddering at stops and the brake lights might not work, which is unsafe. Check the brake lights and fix the cause soon.

How much does it cost to fix P0719?

Often the repair is a low-cost brake switch or a wiring fix. The exact cost depends on the vehicle and the cause.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.