Throttle Position Sensor/Switch A Circuit Range/Performance Problem
The throttle position sensor circuit has a performance issue.
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 throttle position sensor tells the engine computer how far the accelerator is pressed. If it sends incorrect readings, the computer can't adjust the engine power correctly, making it perform poorly.
What the computer is actually seeing
The PCM expects a voltage signal from the throttle position sensor that varies between 0.5V and 4.5V, depending on accelerator pedal position. If the voltage stays outside this range, the code sets.
What a healthy reading looks like
Expected throttle position sensor voltage should range from 0.5V (idle) to 4.5V (full throttle).
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 connector and wires for damage; repair any issues found. Check for continuity and proper ground. Decision: If issues found, repair and retest. If none found, move to step 2.
- 22. Using a multimeter, check the voltage at the throttle position sensor. Expect readings between 0.5V and 4.5V. Decision: If readings are in range, replace the throttle position sensor. If not in range, check wiring continuity back to the PCM. Move to step 3.
- 33. Measure the voltage at the PCM connector that corresponds to the throttle position sensor pin. Compare this to the expected voltage. Decision: If voltage at the PCM is normal, suspect a faulty PCM. If not, further inspect wiring.
Common causes
- Faulty throttle position sensor
- Damaged wiring or connectors
- Poor ground connection
- Faulty PCM (rare)
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It may be drivable, but expect reduced power and performance; fix it soon.
Will this code come back after clearing?
If the underlying issue isn't fixed, it will likely reappear.
Why does this code sometimes occur with P2135?
P2135 indicates a problem with the throttle position sensor range, which often happens in conjunction with P2120.
Working a real vehicle right now?
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