Throttle/Pedal Position Sensor A/B Voltage Correlation
The throttle and pedal position sensors are not matching within expected parameters.
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What it means (plain English)
The vehicle has two sensors that report how far the gas pedal is pressed. If they send different signals, the computer gets confused.
What the computer is actually seeing
The Engine Control Module (ECM) expects to see similar voltage values from both throttle position sensors (TPS). If TPS1 reports a voltage of 0.5V and TPS2 reports 3.5V under the same conditions, a P2131 code triggers.
What a healthy reading looks like
Both TPS should report similar voltages; ideally within 0.1-0.2V of each other under the same pedal position.
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. Visually inspect wiring and connectors for damage, corrosion, or loose connections. Repair any issues found.
- 22. Use a multimeter to measure the voltage output of both TPS sensors at various pedal positions. Expect values to be within 0.1V of each other.
- 33. If voltages differ significantly (more than 0.2V), replace the faulty throttle position sensor.
- 44. If voltages are similar, check for issues in the wiring between the sensors and the ECM; repair if necessary.
- 55. If all else is okay, consider replacing the ECM as a last resort.
Common causes
- Faulty throttle position sensor
- Wiring issues between sensor and ECM
- Poor connections at the sensor or ECM
- Corroded terminals
- ECM issues
Typical repair cost
$$$
Related codes
Frequently asked questions
Can I drive the vehicle with this code?
Yes, but the throttle response may be limited and drivability could be affected.
Will the code come back after I clear it?
It may return if the underlying issue isn't fixed, such as a faulty sensor or wiring problem.
Why does this code appear with other codes?
Multiple codes can indicate related issues like electrical problems affecting both the pedal and throttle position readings.
Working a real vehicle right now?
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