Torque Converter/Brake Switch B Circuit High
The P0724 code indicates that the Powertrain Control Module (PCM) has detected a high voltage signal from the brake switch B circuit, which is part of the torque converter clutch (TCC) control system. This circuit monitors brake pedal position to disengage the TCC when braking. A high voltage reading suggests a short to power, faulty brake switch, or wiring issue, potentially causing the TCC to remain engaged during braking, leading to stalling or poor drivability.
1. Symptoms You Will Notice
- Check Engine Light on
- Torque converter not disengaging when braking
- Engine stalls when coming to a stop
- Harsh or delayed shifting
- Brake lights may not work properly
2. Most Common Causes
- Faulty brake switch B
- Short to power in brake switch circuit
- Damaged wiring or connector
- Corroded terminals
- PCM failure (rare)
3. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P0724 is present.
Step 2: Visually inspect brake switch and wiring for damage or corrosion.
Step 3: Test brake switch operation with a multimeter; check for voltage at switch connector.
Step 4: Check for short to power in the brake switch B circuit.
Step 5: If wiring and switch are OK, test PCM input/output signals.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The torque converter may not disengage, causing stalling or transmission damage.
How much does it cost to fix?▼
Typically $50-$150 for a brake switch replacement; more if wiring repair is needed.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.