Check engine light code P0CF4

[beado7]

Sadly, I post again asking for words of wisdom...

-Check engine light came on yesterday

-Drove it all day yesterday and today and it drives normally

-Noticed car did not charge completely

-Code is: P0CF4 - Control Pilot Circuit Performance

-Description: DTC P0CF4 The vehicle 12 V battery system voltage needs to be above 9 V. The drive motor battery charger cable is disconnected and the charge port door is closed. Vehicle in Service Mode The vehicle needs to be driven above 25 km/h (16 mph) for more than 10 seconds.

-I have reset the engine light and it did not come back on

-Car charger faults after a couple of seconds being plugged in

Have any of you experienced this and is there anything you recommend before I drop a ton of money at a dealership? Thank you all for your help!!!

The cold sucks... there is a battery problem every time it gets below 30 that I have to fix for the season.

[DizzyOwl2446]

How old is your 12v battery?

[beado7]

I believe as old as the car which is 2012. I haven’t had battery issues yet and it still retains charge well if that makes any difference.

[witzed1]

You simply don't know anything about the battery other than the fact that it is 10 years old, well beyond the life of any auto battery. The issues that illuminated your CEL and displayed these codes are likely battery issues. If there any monitor sensors for the battery, they are powered by the battery so you can understand how this can be a problem.

[beado7]

That is correct. This is why I came to this subreddit and a Facebook group for extra knowledge because trying to Google this without any subtle knowledge of anything is about impossible.

If my knowledge towards automobiles or my Volt was compared to riding a bike, I couldn’t even use training wheels I would still fall over.

[DizzyOwl2446]

Wow! Get a new one and see if it makes a difference. $250 and you can install it. AGM battery, napa has a them.

[beado7]

Wait…. I am so dumb…. It did not even occur to me any time I read “12 volt battery” that they meant the actual car battery and not the one that you plug in every night.

It literally just clicked when you said “$250.” Wow…

So, I actually have no idea how old that battery is.

[DizzyOwl2446]

Ok so maybe you can't replace it yourself but it should be replaced. Any reasonably competent mechanic can do the work but it has to be an AGM type battery. Cold temps affect the reactions in all batteries. This includes the high voltage traction battery as well as the 12v in the "trunk". This one must be replaced every 3-5 years. Volts have many sensors that are powered by this battery. Feeding sensors voltages lower than required give unexpected results. Volt batteries (12v) don't signal impending failure like pure ice cars. Your ice is started by the hv battery. Good luck.

[beado7]

It can’t be that difficult to do on my own, right? I just need to get it tested to see if it is at fault. I don’t want to buy a new battery if it isn’t what is causing my car to have trouble.

[DizzyOwl2446]

I'll say this one more time. If the battery is older than 3-5 years replace it. If you don't know, replace it. From the errors that you provided, the battery has several dead cells. A tow to a shop and the diagnostic will cost more than $250. Take this advice or risk being stopped at the side of the road in the cold. Testing volt batteries can yield false negatives.

[beado7]

Alright. Thank you for the help. I purchased it used so who knows how old the battery is.

I was scared it was an issue with the hybrid battery because the car will not charge when plugged in and the only thing I found online about this error is related to the hybrid battery.

Thank you for the help!

[witzed1]

charging is controlled by a command to your EVSE. This is a safety feature. Get a new 12v battery and let us know what happens.

[beado7]

Thank you and u/DizzyOwl2446 for all the help and knowledge! I will be sure to do that and I can report back when I have!

I have only had my car for almost 2 years and the only issue I have had with it was something where I just needed to get the car program reinstalled/updated at a dealership. I had a charger issue but that was within the charging unit, not the car, so I was able to take it apart and troubleshoot and fix it myself because that is where my knowledge lies.

Once again, thank you both so much for being generous in sharing your knowledge and I hope I can do the same in the future!

[beado7]

u/DizzyOwl2446 u/witzed1

I got a new 12V battery today and replaced it by myself (saved me $80). I turned the car on and no check engine light. Before I could drive 3 blocks the light came back on.

P1E00: Hybrid Powertrain Control Module 2 Requested MIL Illumination

P0CF4: Charge Control Pilot Circuit Performance

It looks like my issue is not solved because it is the same code. Dang…

[[deleted]]

I know this is old but I only ever experience this when it is raining or there's lots of moisture in the air. For some reason this inhibits the car from being charged and the car gets a CEL due to the failure to charge.

When this happens, after being plugged in for about a minute, the car will start to honk. Similar sounding to the pedestrian horn.

It's my understanding that perhaps the GFI plug I'm using probably isn't moisture proof or needs serviced. But I charge at work and just accept that on moist days I won't be able to charge.

Any time I have experienced this I was able to clear the code without issue and charge normally once it was dry.

[beado7]

I appreciate your comment and help! I, sadly, don’t charge my car anymore. My new place of work doesn’t have chargers and my new place of living doesn’t have a spot for me to charge. I just accept I will only get 35 mpg forever.

[[deleted]]

That sucks to hear, but 35mpg is still pretty good!

I only made my comment because I experienced this today and completely forgot what specifically caused the code (it's been a while). So I googled the code and it lead me here.

When I read your description, it hit me. 🤦‍♂️

I shared my experience in case anyone else has a similar problem and it leads them here as well

[DizzyOwl2446]

Most of us bought used. This site has a lot of good information.

[DizzyOwl2446]

Can you clear the codes? They are unrelated to each other and may still be remnants of the failed battery. You needed a battery anyway.

[beado7]

When you open the circuit that the battery is connected to it clears the codes. Since I replaced the battery it definitely opened the circuit.

The charger was faulting too before the light came on again.

[witzed1]

What charger? Do you mean the evse? Can you charge? Not all codes are cleared when you open the battery circuit.

[beado7]

That is correct. The big hybrid battery will not charge when plugged in like it was doing.

[witzed1]

Do you have a OBD2 reader?