how to clear a p1589 error code?

You must first remove and replace the sensor which is at the base of the gas pedal then you must clear the codes. Here is a guide and a diagram (below) to help you get the job completed.

https://www.2carpros.com/articles/check-engine-light-clear-codes

I would try to service the throttle bore as well, when it gets dirty it will cause this problem.

https://www.2carpros.com/articles/throttle-actuator-service

Please let us know what you find.

I had this problem nad servicing the throttle bore fixed it! FYI