Possible causes

– Faulty Accelerator Pedal Position Sensor
– Accelerator Pedal Position Sensor harness is open or shorted
– Accelerator Pedal Position Sensor circuit poor electrical connection
– Faulty Electric Throttle Control Actuator

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– No Accelerator Pedal respsonse

P2138 HONDA Description

When the accelerator pedal is pressed, the Engine Control Module (ECM) opens the throttle valve depending on the Accelerator Pedal Position (APP) sensor signal. As the accelerator pedal position changes, the sensor varies the signal voltage to the ECM.