Transmission Fluid Pressure Sensor/Switch B Circuit High
This code indicates that the transmission fluid pressure sensor is reading a high voltage signal.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The transmission fluid pressure sensor measures the pressure of the fluid in the transmission. When it's working right, it sends a signal to the computer, usually between 0.5 and 4.5 volts. A reading above 4.5 volts means there's a problem, often due to a bad sensor or wiring issue.
What the computer is actually seeing
The computer expects the fluid pressure to correspond with a specific voltage signal depending on the pressure conditions inside the transmission. A voltage above 4.5 volts is considered too high and triggers the fault code.
What a healthy reading looks like
The sensor should output a voltage between 0.5 to 4.5 volts depending on fluid pressure; 4.5 volts or higher indicates a fault.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the transmission fluid level and condition; it should be at the recommended level and clean, not burnt. If low, refill and retest.
- 22. Inspect the wiring and connectors to the transmission fluid pressure sensor for damage or corrosion. Repair or replace as needed.
- 33. Using a multimeter, measure the voltage output at the transmission fluid pressure sensor; it should be between 0.5 and 4.5 volts. If it’s higher than 4.5 volts, replace the sensor.
- 44. If the sensor is functioning properly, check the transmission control module (TCM) for faults or updates.
Common causes
- Faulty transmission fluid pressure sensor
- Shorted wiring in the sensor circuit
- Improper fluid level or type in the transmission
- Connector issues or corrosion
- Transmission control module (TCM) malfunction
Typical repair cost
$$-$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's best to fix it soon; you could experience shifting problems.
Will this code come back after resetting?
If the underlying issue isn’t fixed, yes, it will return.
Why might this code pair with other codes?
It often pairs with other transmission-related codes due to shared components or systems.
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