Hello,
Just got my car last week. Today my wife says she got on the freeway home and the check engine light comes on.
I drive car and it runs great. No odd sounds, Engine sounds good, nothing. Light is still on
I go to Autozone. the OBD say p0128.
The computer says "engine coolant is cooler that it should be
Autozone man says he thinks it could be the thermostat
Any thoughts from anyone?
thanks in advance

 

A new thermostat cleared that code for me. Try that first and clear the code at Autozone. If it comes back replace the coolant temp sensor.

 

X2 on the t-stat. Fixed mine right up.