Throttle/Pedal Position Sensor A Circuit High Input
The throttle position sensor A is sending a high signal input.
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What it means (plain English)
The throttle position sensor measures how far the gas pedal is pushed. If it sends a signal that's higher than normal, it means the computer thinks the pedal is pushed too far when it isn’t, which can confuse the engine's control system.
What the computer is actually seeing
The Engine Control Unit (ECU) sees a voltage input greater than 4.5 volts when it should be around 0.5 to 4.0 volts depending on pedal position.
What a healthy reading looks like
Typically, the throttle position sensor should show a voltage between 0.5 to 4.0 volts, proportional to the pedal position; closed throttle should be about 0.5 volts, and wide open should be near 4.0 volts.
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. Inspect the throttle position sensor wiring for physical damage or corrosion. Decision Point: If wiring is damaged, repair/replace as needed. If wiring is fine, proceed to step 2.
- 22. Check the throttle position sensor connector for corrosion or poor contact. Decision Point: Clean or repair the connector if necessary. If connector is good, proceed to step 3.
- 33. Test voltage at the throttle position sensor harness with ignition on but engine off. Decision Point: If voltage is above 4.5 volts, replace the throttle position sensor. If readings are within range, check and test the ECU input for faults.
Common causes
- Faulty throttle position sensor
- Wiring issues (short circuit to power)
- Damaged connectors
- ECU malfunction
- Intermittent issues caused by corrosion or dust
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive long distances; limited engine performance can lead to stalling or reduced power.
Will this code come back after clearing it?
It may return if the underlying issue isn't fixed; check for wiring issues first.
Why does this code appear alongside P0122?
P0122 indicates a low input, while P0123 indicates high input, showing sensor malfunction or wiring issues.
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