P0719
UniversalTorque Converter/Brake Switch B Circuit Low
Medium SeverityThe P0719 code indicates that the vehicle's computer has detected a low voltage signal in the brake switch B circuit, which is crucial for controlling the torque converter clutch. This issue can lead to improper torque converter operation, affecting transmission shifting and potentially causing the engine to stall when stopping.
⚠️ Before You Begin (Safety First)
Always disconnect the battery before working on electrical components to prevent accidental shorts or injury. Use proper jack stands when working under the vehicle.
Common Symptoms
- Check Engine Light illuminated
- Torque converter not locking up or unlocking properly
- Engine stalling when coming to a stop
- Harsh shifting
- Cruise control not working
- Brake lights not functioning correctly
Common Causes
- Faulty brake switch (most common)
- Wiring issue in the brake switch B circuit (e.g., short to ground, open circuit)
- Corroded or loose electrical connectors
- ECM/PCM failure (rare)
Frequently reported on: General/Universal
Diagnostic Steps
- Verify the code with an OBD-II scanner and check for other related codes.
- Visually inspect the brake light switch and its wiring for any obvious damage, corrosion, or loose connections.
- Test the brake switch's functionality using a multimeter to check for proper continuity and voltage signals when the pedal is pressed and released.
- If the switch is faulty, disconnect the battery and replace the brake switch, typically located near the brake pedal arm.
- Clear the code and test drive the vehicle to ensure the issue is resolved and the code does not return.
👨🔧 When to Call a Professional
If after replacing the brake switch the code persists, or if you suspect deeper transmission issues like harsh shifting or stalling unrelated to the brake pedal, it's time to consult a professional mechanic for advanced diagnostics.
Commonly Asked Questions
What is the "B Circuit" referring to in P0719?
In this context, "B Circuit" often refers to a secondary circuit within the brake switch or a specific input to the ECM/TCM that signals brake pedal application, distinct from the primary brake light circuit. It's often related to cruise control or torque converter clutch control.
Can a faulty brake switch cause my car to stall?
Yes, if the ECM/TCM doesn't receive the correct brake pedal signal, it might not properly unlock the torque converter clutch when coming to a stop, leading to the engine stalling.
Are the brake lights affected by P0719?
Not always directly. While some brake switches control both the brake lights and the signal to the computer, the "B Circuit" might be an independent signal for transmission or cruise control. However, it's worth checking your brake lights if you have this code.
Is it safe to drive with a P0719 code?
Driving with a P0719 code is generally not recommended if it's causing stalling or erratic shifting, as this can be unsafe. If it's only the check engine light with no noticeable symptoms, it might be less urgent but should still be addressed promptly.
How much does a new brake switch cost?
Brake switches are generally inexpensive, often ranging from $15 to $50 for the part, making this a relatively affordable DIY repair.