Escalade Hybrid P0AC4 Dallas Texas
 

I've got a 2009 Escalade Hybrid with 130000 miles that came to an abrupt stop yesterday at about 3 to 5 mph while in auto stop mode and the check engine light came on. I took it to autozone to have it pulled and there was only one code which was P0AC4.

I just want to know if there are any recommendations in the Dallas area for a knowledgeable hybrid mechanic. Hoping to avoid the Cadillac dealer if possible.

Thanks in advance.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

says P0AC4

Monitor hybrid control module HCP MIL request to determine when the HCP has detected a MIL illuminating fault


So what is the second code???

normally the P0AC4 comes on with another one

Re: Escalade Hybrid P0AC4 Dallas Texas
 

The printout that autozone provided had P0AC4 listed twice, but there were no other codes.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

As an update, the check engine light has turned off on its own, but I would still like to find someone locally to check it out.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

Get your 12V load tested. Don't care how new it is.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

I ran a couple of tests with my multimeter and then took it to oreillys to load test it and the battery seems to be good.

Initially with the multimeter it read 12.60V, then I left the lights on for a bit and retested it and it was at 12.34V. I also tested the voltage while starting the car and it never dropped below 12.18V.

Let me know if you have any other suggestions. Thanks!

Re: Escalade Hybrid P0AC4 Dallas Texas
 

Get yourself a decent code reader and read the codes again. That code must come with another one that tells more about what actually failed to cause the Check Engine light to be turned on. P0AC4 is basically just saying that the Hybrid Powertrain Control Module has requested that the check engine light be turned on.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

Bought the BAFX OBD2 code reader as suggested in this forum and the second code is P061B.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

https://www.greenhybrid.com/forums/f...d-codes-31782/

and

https://www.greenhybrid.com/forums/f...results-31736/

BTW... I have the BAFX. It's pretty low end. Works okay with Torque Pro though.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

Thanks for the links. Based on the links, it seems likely that my battery will need replacing/reconditioning. I’ll be running the battery test in a few days. Provided that is the problem, what are your thoughts on the options below?

1. New GM battery
2. Local reconditioning https://endeavsys.wordpress.com/hybr...econditioning/
3. Recondition with prolong charger https://hybridautomotive.com/
4. DIY reconditioning with a bunch of Dynam Supermate DC6s
5. Salvage yard replacement with 70k miles or less if possible.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

Do a little research on this site and you will come to the following conclusions:

1) is the only long term solution that ensures you're not p!ssing your money away.
2) is not possible. 38 of your 40 modules will have only a tiny fraction of their rated capacity and can't be reconditioned. 1 will be about 30-50% and one will be 50-70%. Furthermore, that local resource is likely not competent. He has made at least 3 incorrect statements or made false claims. He will take your money, and you will be trying to find his number again in a few months. Or you're going to be outraged when he tells you that you need 38 modules, and it's going to cost you over $2K - that's only if he's honest and using quality modules.
3) See #2
4) See #2
5) The amount of deterioration can be astounding. You could easily spend a lot of money on a part with only 20-25% of its life remaining, and you would have no way to confirm it. I've had multiple vehicles at the 100K mark with massive permanent damage across almost the entire pack, and these are vehicles with much better overall battery management/performance than the GM hybrids.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

Thanks again. New battery it is.

It seems that the current GM battery part number is 84141586. Are you aware of any members that have sourced one in a reasonable amount of time? I’m concerned that the current battery may leave me stranded pretty soon.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

It seems that most are initially told that they will have to wait weeks/months, but then batteries become available in a much more reasonable time frame.

Re: Escalade Hybrid P0AC4 Dallas Texas
 

According to the Hybrid CEL codes user manual the 2ML70 Transmission Output Shaft Speed Sensor is broken or bad or vehicle speed sensor

https://gsi.ext.gm.com/gmspo/mode6/p...iagnostics.pdf


just hit control F then type in the code you have for full details



I have sourced NEW GENUINE GM hybrid batteries module
that can be ordered for at slightly above COST price (cost price is)$2900 +core +tax.
you save 1,000$ anyways
(they are able to move a lot of inventory that way that means when they order they get the parts faster)

it's only local pick up at a dealership I can't publicly post that dealer :zip: that but it's kinda of a road trip for you though..
he said they can have it in right away...must be pre-ordered/prepaid though. since it's a special order item.

I recommend that you let the dealer install it so they can still make some money off the deal (remember one hand washes the other hand) :D


7 things can cause that code


did you get the code at low speed of 7 mph or less?


check the
MAP sensor make sure it's changing up and down with a live OBD2 reader
that sensor will effect the hybrid system significantly... As it did for me