limp mode on 2008 optima with code p0698 and p0638

Question

cleaned throttle body and mass air flow sensor

Answer 1

Hi there,

P0638 indicates an issue with the throttle actuator. Here is a list of possible causes. 

P0638 KIA - Throttle Actuator Control Range/Performance

Read more: https://www.autocodes.com/p0638_kia.html

P0698 indicates an issue with the ECM. Here is a list of possible causes.

P0698 KIA - Sensor Reference Voltage 'C' Circuit Low

Read more: https://www.autocodes.com/p0698_kia.html