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SPN 2550moderate severity✨ AI-generated

Acceleration Pedal Position 1 - Above Normal Operating Range - Moderately High

The engine control unit detects a high reading from the acceleration pedal position sensor.

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 sensor that tells the engine how much you’re pressing the gas pedal is seeing a voltage drop below 0.5 volts or above 4.5 volts when it shouldn't. This can throw off the engine's response and cause performance issues.

What the computer is actually seeing

The computer is tracking the acceleration pedal's voltage signal, expecting it to land between about 0.5 to 4.5 volts based on pedal position, but it's reading outside of this range.

What a healthy reading looks like

Normal voltage should vary from 0.5V at rest to about 4.5V at 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.

  1. 11. Inspect the wiring and connector at the accelerator pedal sensor for damage or corrosion. If damaged, repair or replace as needed. Decision point: Are the connections clean and intact? If no, repair; if yes, continue.
  2. 22. Measure the acceleration pedal position sensor voltage with a multimeter. Check at rest and full throttle. Expect 0.5V at rest and 4.5V at full throttle. Decision point: Do readings fall within normal range? If no, proceed to step 3; if yes, suspect PCM/software issue.
  3. 33. If the sensor voltage is out of range, replace the sensor. Clear codes and test drive for symptoms. Decision point: Does the code return? If yes, re-check wiring; if no, repair is complete.

Common causes

  • Faulty acceleration pedal position sensor
  • Wiring issues such as shorts or opens
  • Failed connector or poor connection
  • Mechanical binding of the accelerator pedal

Typical repair cost

$$$

Related codes

Frequently asked questions

Can I still drive the vehicle?

It's drivable, but expect reduced performance and potential safety risks. Fix soon.

How likely is it that this will come back after repair?

If wiring is intact and the new sensor is installed correctly, it should not return.

Why does this code sometimes pair with other codes?

Issues with the accelerator pedal position can affect multiple sensors or systems, leading to multiple fault codes.

Working a real vehicle right now?

Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.

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