Q: Engine code P1589 - how to fix? Toyota Corolla

Hello - this diagnostic code, P1589, is a throttle relearning error - typically done after a throttle control unit is replaced. This error occurs during deceleration testing, when the vehicle is almost at a stop - but the acceleration sensor in the vehicle doesn’t register that deceleration correctly. This could be a testing error (not on flat, smooth ground), a problem with the throttle unit (or its wiring), or another procedural problem with the relearn process. I recommend a throttle body replacement service performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, re-install the control unit, and re-do the "re-learning" procedure.

Hello. Code P1589 will set if a malfunction is detected with the throttle body, acceleration pedal position sensor, or a throttle position sensor. Code 1589 will also set if the values of the acceleration sensor, and throttle position are not within a reasonable range of one another. Also, the code can set if the engine control module runs a self test on the throttle body and the throttle body is unable to fully return to the closed position. You may have excessive carbon buildup inside of your throttle body Inlet preventing your throttle plate from fully closing. If that is the case a throttle body cleaning should fix code P 1589. You will also need to have your throttle position sensor and accelerator pedal position sensor tested to make sure those aren’t the issue. A technician with a good scan tool or multimeter will be able to test your position sensors to further diagnose your vehicle.

Here’s a little additional info on the sensors I mentioned

https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-throttle-position-sensor

https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-throttle-accelerator-pedal-position-sensor

Please keep in mind that the technicians here at YourMechanic can perform those repairs and diagnostics.

You are able to find a technician and schedule an appointment here

https://www.yourmechanic.com