Mazda 2014 CX5. The engine light came on. The code is P011A.

Question

Dealer said the heater core needs to be replaced.  How does the heater core relate to this error?  Dealer said they will have to remove about 800 parts to replace the heater core.

Answer 1

P011A ECT sensor number 1 / number 2 performance problem

There are 2 engine coolant temperature sensor coolant temperature number 1 is at the top of engine  and coolant temperature sensor number 2 is located near the heater core but located on the outside on one of the water outlet, Neither requires the removal of the heater core, Unless you have a problem with the heater core such as a heater core leak.