What does it mean?
P1765 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Throttle Valve Signal Plausibility .
Symptoms
- MIL (check engine lamp) is on, often together with engine-side throttle codes
- Transmission goes to limp mode and holds a single gear
- Shift points are clearly wrong: far too early, far too late, or the box hunts between gears
- No kickdown response when the accelerator is pushed to the floor
- Reduced engine power, hesitation or a flat spot when pulling away
- Unstable idle or the engine settles at a higher than normal idle speed
Likely causes
- Throttle position sensor worn or out of calibration, so the reported angle does not match actual plate position
- Carbon build-up in the throttle body holding the plate slightly open against the learned zero point
- Throttle body adaptation (basic setting) never performed after cleaning, replacement or a battery disconnection
- Corroded connector, broken 5 V reference or missing ground at the throttle position sensor
- Missing or corrupted throttle load message on the data bus between the engine and transmission control units
- Low system voltage or a poor module ground shifting the reference and skewing the reading
- Failed throttle actuator motor or its position feedback track
How to fix it
- Scan every module and deal with engine-side throttle and bus faults first; this code is frequently a consequence of one of them
- Watch the throttle angle in live data through a slow full sweep, looking for dropouts, sticking values or a non-zero closed reading
- Remove and clean the throttle body, then run the manufacturer adaptation routine and re-check the closed value
- Back-probe the sensor connector: verify 5 V reference, ground and signal while flexing the harness
- Check communication between the engine and transmission modules, including bus wiring condition and terminating resistance
- Replace the sensor or throttle body only after the signal is proven erratic, and always re-run adaptation afterwards