Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance Problem
The Throttle Position Sensor has a range or 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 (TPS) measures how far open the throttle is. If it's off, the engine can't adjust the air and fuel mixture properly, which can cause power loss or stalling.
What the computer is actually seeing
The Engine Control Module (ECM) expects a TPS voltage signal between 0.5V (closed throttle) to 4.5V (wide open throttle) and uses this input to control fuel delivery and ignition timing. If it sees a reading outside this range, it sets this code.
What a healthy reading looks like
TPS should vary smoothly from 0.5V to 4.5V as the throttle opens. At idle, you typically see around 0.6V - 0.8V; at wide open throttle, around 4.0V - 4.5V.
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 for visible wiring damage or corrosion at the throttle position sensor connector. Repair as needed. Decision: If repairs made, clear codes and retest. If not, proceed to step 2.
- 22. Using a multimeter, measure the voltage at the TPS with the ignition on (engine off). Expected at closed throttle: 0.5V - 0.8V. At wide open throttle: 4.0V - 4.5V. Decision: If readings are within range, inspect accelerator pedal sensor. If not, replace TPS.
- 33. If TPS needs replacement, disconnect the battery, swap in a new sensor, and reconnect the battery. Clear codes and test drive the vehicle. Decision: If the code returns, inspect wiring and connectors. If not, the issue is resolved.
Common causes
- Faulty throttle position sensor
- Loose or corroded connections
- Faulty accelerator pedal position sensor
- Wiring issues or shorts in the TPS circuit
- Air intake leaks affecting sensor readings
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable, but there may be power loss or stalling. Best to fix soon.
Will this code come back after I clear it?
If the underlying issue isn't fixed, yes, it will likely return.
Why does this code pair with P0221?
P0221 usually indicates a problem with the accelerator pedal position sensor, which can affect the TPS performance.
Working a real vehicle right now?
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