As the title states, I have a 2009 2.3 Ranger thats just ticking over to 130k miles. I've been happy with her for the 3 years that I've owned her and for the most part she's been trouble free.
Last winter 2 issues started manifesting rather simultaneously.
1; A check engine light related to the temperature sensor, as well as intermittent temperature-gauge function.
2; The A/C Blending started failing, where its only cold on Max A/C, and on anything else its entirely hot.
Based on the reading I have already done from some insightful threads here in this forum, the 2.3 Duratec does not have an ECT Sensor, but has a Cylinder Head Temperature sensor, and an ECT sender.
From what I have read, if the CHT sensor fails, it will not let the temperature gauge read, which it currently does not. Additionally, it is apparently able to affect the operation of the A/C Blending Unit.
The printout from my failed smog-test says error code
P0128; Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
So while this says its the thermostat, I think that the p0128 code is a generic OBD code, and so the "Coolant Thermostat" failure might rather be implying there is a failed temperature sensor, since there's actually no sensor in the thermostat. Since my heater is working fine too, it would seem my thermostat is also operating normally.
Am I reading this right?
Temp gauge began failing with intermittent function.
Temp gauge is now "dead" hard pegged on cold (operating stable for last 8 mos)
Engine produces heat fine/ Heater works great.
A/C Blender function failed at approximately the same time.
Engine trouble code P0128.
Suspected Fault: CHT Sensor.
start just replacing these parts, but I'm more interested in understanding what these do so I can troubleshoot them accurately, and I really dont wanna rip out my dashboard to replace the AC blender unless its actually at fault.
Thanks in advance for any input, and thanks for the insightful answers already on this topic.