P0719: Torque converter and brake switch B circuit reading low
Torque converter/brake switch B circuit low
Severity: Severity not verified — if the car runs badly, have it inspected
We found no source rating P0719. 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 braking.
P0719 in short
P0719 means the computer sees a low signal from the torque converter and brake switch B circuit. The brake light switch, its adjustment, blown fuses or bulbs, and corroded wiring 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. P0719 sets when the switch B circuit voltage reads lower than expected.
TroubleCodes.net says the brake switch, or its adjustment, is the most common cause and warns against replacing the converter solenoid first. Brake lights that do not work are a safety issue, so confirm they work.
Most likely causes
These are general causes for this code across vehicles. None is specific to one make or model.
Cause 1: Brake light switch failure or misadjustment
Common general cause- Why it ranks here
- TroubleCodes.net lists the brake switch and its adjustment as the most common cause.
- What would change this
- Rises if the brake lamps stay on, stay off or act oddly. Falls if the lamps and switch work normally.
Cause 2: Blown fuses or bulbs, corroded connectors, or damaged wiring
Common general cause- Why it ranks here
- TroubleCodes.net lists fuses, bulbs, corroded connectors, chafed or open wiring and poor grounds.
- What would change this
- Rises if a brake bulb holder is corroded or a fuse is blown. Falls if power and ground at the switch test good.
Cause 3: Engine or transmission computer fault
Possible — needs testing- Why it ranks here
- TroubleCodes.net says computer failure is rare and comes 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. Have the switch and wiring tested.
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, faulty, or the wiring or connector is damaged
It meansRepair or replace it.
IfFuse, bulb or ground faults are found
It meansRepair the fuse, bulb holder or ground.
Points to: Blown fuses or bulbs, corroded connectors, or damaged wiring
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 braking (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 P0719 yet. The causes and tests above apply across vehicles.
Related codes
P0719 questions
What does P0719 mean?
The torque converter and brake switch B circuit reads low. The brake light switch circuit is the usual place to look.
Is it safe to drive with P0719?
Check that the brake lamps work first. Failed brake lamps are a crash risk, so have the brake switch checked promptly.
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