P2138 ACURA – Accelerator Pedal Position Sensor A/B Incorrect Voltage Correlation

P2138 ACURA Possible Symptoms

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

P2138 ACURA 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

P2138 ACURA Description

Accelerator Pedal Position (APP) sensor A and Accelerator Pedal Position (APP) sensor B are potentiometers, and they are installed in the engine compartment. Accelerator Pedal Position (APP) sensors A and B are operated via the throttle cable to determine the accelerator opening value when the driver presses the accelerator pedal. The accelerator pedal opening value is converted to a signal in APP sensors A and B and transmitted to the Powertrain Control Module (PCM) to compute the target position. The target position signal is transmitted to the throttle actuator control module via the circuit. APP sensor A is for the primary control, and APP sensor B is a back-up of APP sensor A in case it malfunctions. Both sensors compare their output voltage to each other for malfunction detection. When the voltage difference of APP sensor B is out of a fixed range for a set time, the PCM detects a malfunction, and a DTC is stored.