The main reason for the monitors not to set is a thermostat that is stuck open and the engine does not warm up within the prescribed time.
Here is a guide that will help you confirm the problem:
https://www.2carpros.com/articles/replace-thermostat
Here is what it will be like on your car.
Please let us know what you find.
Cheers, Ken
Images (Click to make bigger)
Friday, August 25th, 2017 AT 1:20 PM