A delayed response from the accelerator pedal in your 2021 Honda Accord can make the car feel sluggish and unresponsive. When accompanied by code P2122, you're dealing with a throttle/pedal position sensor circuit low input condition that Honda's powertrain control module has detected.
How Honda's Drive-By-Wire System Works
The 2021 Accord uses an electronic throttle control system where the gas pedal sends electrical signals to the PCM, which then commands the throttle body to open. There's no physical cable connecting your foot to the throttle—everything is electronic. Code P2122 specifically indicates Sensor D (the primary APP sensor) is reading lower voltage than expected.
What Causes the Delay and P2122
The pedal delay with P2122 often stems from: a failing accelerator pedal position sensor with worn internal contacts, an open circuit in the 5V reference wire to the sensor, high resistance in the signal wire due to corrosion, or a PCM issue with the internal pull-up circuit. Floor mat interference can also cause symptoms if it restricts pedal movement.
Recognizing the Problem
Owners describe pressing the gas and waiting one to three seconds before the car responds, a dead spot at the beginning of pedal travel, the car seeming to have a mind of its own regarding when to accelerate, and occasional surging once it does respond. The check engine light illuminates, and the car may limit power as a protective measure.
Proper Diagnosis Process
Diagnosis requires monitoring the APP Sensor D voltage at rest (should be around 0.5-0.8V) and at full throttle (should reach 4.5V or higher). The voltage should increase smoothly and proportionally as the pedal is pressed. Any flat spots, dropouts, or erratic readings indicate sensor failure.
Fixing the Delayed Throttle
The accelerator pedal assembly is the most common repair for P2122 on the Accord. Honda's pedal assembly is a replaceable unit that includes both APP sensors. After installation, clearing codes and test driving verifies the repair. Unlike some vehicles, the Accord typically doesn't require a formal throttle relearn procedure.