Transmission Fluid Pressure Sensor/Switch E Circuit Range/Performance Problem
There's an issue with the transmission fluid pressure sensor or switch E.
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 E measures the pressure of the transmission fluid. If the pressure is too high or too low, or if the sensor has a fault, it signals a problem to the engine control module (ECM).
What the computer is actually seeing
The ECM monitors the voltage from the transmission fluid pressure sensor E, expecting it to stay within a specific voltage range that indicates normal fluid pressure. Outside of this range triggers the fault code.
What a healthy reading looks like
The expected voltage from the sensor should be between 0.5V and 4.5V under normal operation. If the voltage is below 0.1V or above 4.9V, it indicates a problem.
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; top off if low and see if the code returns. Decision: If fluid is low, fix that and retest before further diagnosis.
- 22. Inspect the wiring and connector to the transmission fluid pressure sensor E for any damage or corrosion. Decision: Repair any issues found and retest.
- 33. Use a multimeter to check the voltage output of the sensor. With the engine running, the voltage should be between 0.5V and 4.5V. Decision: If the voltage is out of range or jumps erratically, replace the sensor and retest.
- 44. If the sensor tests good and wiring is intact, check for external influences like a malfunctioning TCM or fluid pressure problems within the transmission.
Common causes
- Faulty transmission fluid pressure sensor E
- Wiring issue or bad connection to the sensor
- Low transmission fluid level or old fluid
- Faulty transmission control module (TCM)
- Mechanical issue within the transmission
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with P0778?
It's moderate severity; it's best to fix soon to avoid transmission issues.
Will this code come back after repairs?
If the root cause was fixed, it shouldn’t return. Monitor for any related symptoms.
Why does this code pair with P0841?
P0841 indicates a similar issue with the transmission fluid pressure sensor circuit; they often fail together.
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