Possible causes
– Drive-by-wire control system malfunction
– Throttle actuator malfunction
– Throttle valve malfunction
– PCM malfunction
– Throttle actuator malfunction
– Throttle valve malfunction
– PCM malfunction
Tech description
Dirty or clogged throttle body can triggered the P0638 code. Before replacing any parts try cleaning the throttle body and reset the engine light.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0638 KIA OBD Code Description