P0724: Torque converter and brake switch B circuit reading high
Torque converter/brake switch B circuit high
Severity: Severity not verified — if the car runs badly, have it inspected
We found no source rating P0724. The code involves the brake light switch, which also controls brake lamps, so treat it as safety-relevant until the lamps are confirmed working.
It gets more serious if:
- Inspect soon: Have it inspected soon if the brake lamps do not light or stay on, or the engine stalls when slowing.
P0724 in short
P0724 means the computer sees a high signal from the torque converter and brake switch B circuit. The brake light switch, its adjustment, a wiring short to power, and corroded connectors are the usual causes. Check the brake switch before replacing transmission parts.
The brake light switch tells the computer when the brakes are applied, so it can release torque converter lock-up and cruise control. P0724 sets when the switch B circuit voltage reads higher than expected.
TroubleCodes.net says the usual real fault is the brake light switch, its adjustment or the connections, and that replacing the converter solenoid is a common mistake. Confirm the brake lights work.
Most likely causes
These are general causes for this code across vehicles. None is specific to one make or model.
Cause 1: Defective or misadjusted brake light switch
Common general cause- Why it ranks here
- TroubleCodes.net lists a defective switch and says it is the usual real fault.
- What would change this
- Rises if the brake lamps stay on or fail to light. Falls if the lamps and switch work normally.
Cause 2: Wiring short to positive, corroded connectors or poor grounds
Common general cause- Why it ranks here
- TroubleCodes.net lists a short to positive, corrosion and poor grounds.
- What would change this
- Rises if the connector is corroded or a harness is chafed. Falls if wiring tests good.
Cause 3: Engine or transmission computer fault
Possible — needs testing- Why it ranks here
- TroubleCodes.net lists the ECM, PCM or TCM, after the other causes.
- What would change this
- Rises only after switch and wiring test good. Falls if a switch or wiring fault is found.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Have someone watch the brake lamps while you press the brake pedal, and look at the brake light fuse and bulbs.
IfThe lamps do not light, or stay on with the pedal up
It meansThe brake switch or its circuit is suspect.
IfThe lamps work normally
It meansCheck the switch connector and adjustment.
Step 2: Have a shop check the brake switch position, connector, wiring and voltage at the switch.
Warning:Brake lights are a crash-safety item. Do not drive with failed brake lamps, and have the brake lights confirmed working after any repair.
IfSwitch is misadjusted or faulty
It meansReplace or adjust it.
IfA short to power, corrosion or a bad ground is found
It meansRepair the wiring.
Points to: Wiring short to positive, corroded connectors or poor grounds
IfThe switch and wiring test good
It meansAsk a shop to test the computer.
Symptoms
- Check engine light on
- Brake lamps that do not light, or stay on Gets more serious: stop and have it checked.
- Cruise control or torque converter lock-up that acts erratically
- Stalling when slowing or stopping (reported on TroubleCodes.net) Gets more serious: stop and have it checked.
How to fix
Parts and cost context
- Transmission control module (TCM):Test the sensor, switch and wiring first. Labour varies; get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
We don't have reviewed vehicle-specific evidence for P0724 yet. The causes and tests above apply across vehicles.
Related codes
P0724 questions
What does P0724 mean?
The torque converter and brake switch B circuit reads high. The brake light switch circuit is the usual place to look.
What is the difference between P0719 and P0724?
P0719 means the circuit reads low and P0724 means it reads high. Both point at the same brake switch circuit.
Sources and review
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error