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P0798moderate severity✨ AI-generated

Transmission Range Sensor Circuit High Input

The transmission range sensor is sending a high voltage signal when it shouldn't.

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)

Inside the transmission, the range sensor tells the computer what gear it's in. A high voltage signal usually means there's an issue in the wiring or the sensor itself.

What the computer is actually seeing

The powertrain control module (PCM) receives a voltage signal that exceeds the expected range, indicating an erroneous position of the transmission range sensor.

What a healthy reading looks like

Expected voltage from the sensor: 0.5 to 4.5 volts, depending on the selected gear.

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.

  1. 11. Check the wiring and connectors for the transmission range sensor for visible damage or corrosion. Repair if necessary.
  2. 22. Measure the voltage at the transmission range sensor connector with the key on (engine off). Expect 0.5 to 4.5 volts depending on position.
  3. 33. If voltage is out of range, test the sensor by unplugging it and checking for continuity of wires to the PCM.
  4. 44. If the wiring is okay, replace the transmission range sensor and clear the code.
  5. 55. If the code returns, check for PCM updates or reprogramming if applicable.

Common causes

  • Faulty transmission range sensor
  • Shorted or open wiring in the transmission range sensor circuit
  • Poor electrical connections or corroded connectors
  • Faulty PCM or software issue

Typical repair cost

$$

Related codes

Frequently asked questions

Can I drive with this code?

Yes, but the transmission may not shift properly, so it's best to fix it soon.

Will this code come back after I clear it?

If the underlying issue isn't fixed, yes, the code will return.

Why does this code pair with others?

It often indicates a fault in the transmission system that could affect multiple sensors.

Working a real vehicle right now?

Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.

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