Hello, I just purchased an 08 Yukon with 67k miles. Bought from a small dealer (not GMC, etc). Vehicle is in fantastic physical condition, test drove great, everythign was operable, etc etc. Was really psyched with it. I have 32 miles on it since I drove off the lot and it stalled out on me today with the service hybrid system warning and would not restart. called tow truck. by the time i got home the vehicle started but of course with the CEL on. I ran a full system scan.

Hyrbid PCM: P0C17 and P0C58
Engine: P0AC4 and P2273.

Some situational additions. This was right after I punched the gas pedal from a slow roll in order to pass someone. I then stopped briefly at a ref light and made a uturn immediately after the light. The Power Steering system failed first as far as I could tell, mid uturn or just barely coming out of it (if memory serves me right, i lost power steering and saw the power steering issue pop up on the dash, and then the hybrid system error).

I called the dealer and he said he would try to help me. I am thinking I should go in and try to throw money at him to unwind the "as is" sale and hope that he releases me from it.

My question is:
1) am I over reacting. I am not able to find the P0C17 and P0C58 combination on this forum. The P0C17 seems like a simple clear of the DTC and recalibration.
2) is there anythign else I should look at? i do have a decent tool -- a mac mentor. I am fairly mechanically inclined but I am new to hybrids and also do not want to pull the battery and manually test a bunch of cells. I will pay a professional for that.

any help or guidance that you can provide is greatly appreciated. Thank you so much.

 

Anytime I hear about unusual code combinations I always suspect the 12V battery out under the hood. Lets get that checked before we jump to a conclusion. Keep in mind the 12V does NOT crank the engine so if it is weak you will Not have the "slow crank" that we are all used to with regular vehicles. The 12V control most electronic modules and things go haywire if it gets weak. Lets keep our fingers crossed here and check that 12v first. This really sounds like a sweet ride. I love my 09 she is cantankerous at times but she is the best cheap beater daily driver that I have ever had.

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I would not argue so easily in my mind about the error P0C17 that it is not so easy to clear or make a calibration because there are many factors that will not allow you to do this.
I would check the 12 v battery, the second thing you need to pay attention to is the hybrid battery, its condition and charge level

​I have a problem with errors P0C17 and P0C18 I can not clear them or do a calibration. I changed the 12v battery, checked the relay and the wiring harnesses, but nothing helped me, my car still would not start. At the moment, I tend to think that my problem in a hybrid battery is more accurate in its low charge level of 213v​​​​​

 

Woke up today to take it over to the dealer and the check engine light is off with no active codes. strange... I did not clear them, nor did i drive the vehicle more than 20 feet from where the tow truck dropped her and my driveway.

I will check the 12v when I get home this evening. heading over to the dealer now to see what he has to say... and if he wants to/can help me with anything

 

they will be happy to help for several thousand dollars as me with the recommendation to replace the transmission for $ 6000 as they could not clear the errors P0C17

 

appreciate the feedback. My codes are gone for the moment and drove 20 miles into the shop. shop did say its more likely to be transmission related than battery related but they would have to look at it. Ill share any additional feedback I get.

 

That is crack head prices

does not sound like a 25 hour job who did they hire Sloths????

i;d wait it out could be the cold effect code effect
i mean you car caught a cold code.

what us the CCA of the battery???
should be at lest 730CCA./910CA.



cold temps outside could trigger phantom or ghost check engine codes
and make the battery appear weak. etc...


just like some people get Ghost or Phantom low oil or no oil pressure Warnings..


if you had no or very low oil pressure you would lock up the engine very quickly..


dealerships will try and take advantage of you with the phantom codes