P0719
Torque Converter/Brake Switch B Circuit Low
Encountering the engine check light code P0719 signifies an explicit mechanical or electrical operational breakdown categorized as "Torque Converter/Brake Switch B Circuit Low". Professional scanner tools usually flag this subsystem loop early on.
Driver's Summary
Code P0719 means your vehicle detected a problem with the torque converter/brake switch b circuit low system. Drivers typically experience torque converter clutch engages erratically, cruise control fails when this code is active. Short trips are generally acceptable, but avoid high-load driving and get this inspected soon.
Symptoms
Torque converter clutch engages erratically, cruise control fails
Common Causes
- Short to ground in the brake switch circuit
- Failed brake light switch
- Misadjusted brake pedal switch
- Water intrusion in the connector
How to Fix
- 1 Repair grounded wiring
- 2 Replace brake switch
- 3 Adjust the switch clearance
- 4 Dry and protect connector
Technical Explanation
Detection of P0719 occurs when the ECM cross-references multiple sensor inputs and determines that the reported values are physically inconsistent or out-of-range. Shift solenoid circuits are monitored for both functional performance (does the transmission achieve the commanded gear ratio?) and electrical integrity (is the solenoid's resistance within the normal range of 10–40 ohms?). The MIL illuminates after the fault is confirmed on two consecutive drive cycles, and the freeze frame data captured at first detection is stored in the PCM's memory for diagnostic reference.
Is It Safe to Drive?
While the vehicle is typically drivable with P0719 active, avoid towing, aggressive acceleration, or extended highway driving until the fault is resolved. The primary risk is accelerated wear on short to ground in the brake switch circuit and failed brake light switch.
Mechanic's Pro Tip
Before replacing any component on P0719, spend 5 minutes inspecting the wiring harness and connector first — corrosion, chafed insulation, and backed-out pins cause the majority of these faults and cost nothing to fix. Use a multimeter to measure voltage drop across the connector pins under load; anything above 0.1V indicates excessive resistance that will cause intermittent failures even after replacing the sensor.
Brake switch replacement: $50 - $150