My check engine light is on showing code P011A. Had both temp sensors replaced, and heater core flushed. Still showing check engine light and same code. Heater works. No idea what else it could be. Read somewhere about PCM needing new programming, but it says cars with a vin lower than mine. Also it’s been very cold in my area lately. Any idea? 2016 Mazda Cx5.

 

Always verify a failed part before replacing them
It is unfortunate that People assume the DTC meanings found on the internet is the target area and without properly diagnosing start replacing parts.

It just is not how it works.

First go back into the ECU and scan all the areas that have DTC and also the state of the I/M monitors.

Then clear the active DTC that actuated the check engine light only.

Then after the engine sits for the night start and drive and as soon as the check engine light is activated again safely pull to the side of the road and go retrieve that DTC.

If it is still the same DTC only then you need to re confirm the parts you replaced were not defective. Then check using your scanner to see if the sensors are registering the same . Then check the continuity of the circuits and connectors. If they are correct then you need to manually check the temperatures using a hand held temperature meter of the coolant . They should match the ECU register. If not then you have a thermostat or coolant flow issues .
If it were a PCM issue there would be other indicators. Part of those may be what you find by doing a proper full scan of the ECU/PCM?

 

Check for corrosion at the connection point. Check the plug.

 

Hi, did you get his worked out? I am having the same problem. I also have that code, brought it into Mazda for a re flash but instead they recommended a heater core flush. My heater in the car is fine and even driver/passenger side so I don't think it is thermostat or heater core. I checked the wiring harness for the PCM but mazda says my PCM is communicating and up to date and my vin is after that TSB also. My OBD reader only showed p011A but Mazda saw p011a, b13d3, u0423 and p0401. It just seems like a lot of codes for a car that is running seeming fine. I only get this set of codes in fall/winter.
I am wondering if you solved your issue - it seems similar and I was be very curious to see if you resolved it!

 

Welcome to the forum
May I suggest that you cut and paste this to a thread you should start about your Mazda problem.
The main reason is that unless you have exactly the same year same miles same everything then your problem and what you are reporting is not the same.
I will look for your thread and try to help a little with your Mazda.



Make sure you also include the same basic information that you would if you filled out a service information because that's what most like me need to begin helping

 

….

 

Unfortunately I had no luck and went the whole winter without heat. I recently sold it and got a cx50 hybrid. Sorry wish I could be more helpful. It really sucks.

 

Well congratulation on your newest MAZDA. Happy that you stayed with the Mazda family of vehicles!

 

Cool yes please do keep an eye out for my post! I am waiting to have time to make one more quick diagnostic before I post. I do have the same year and sounds like similar manufacturing dates for tsb congruence but of course different cars with different histories. I’ll post soon with my card details and case! hopefully you catch my upcoming post! Not sure what you meant about the report

to the original thread poster: sorry about the unsolved issue I know how frustrating that is but congratulations on the new car 🙂

 

I read every new or respond on thread everyday on this forum
The reporting thread It was not you that reported my response and I just noticed I posted it on the wrong thread about that . I have a pia stalker or troll 🧌member that disrupts threads I respond trying to help members with service related issues.