I have a 2009 Escalade Hybrid. Had a 130K on it. Bought it from a person two months ago. Absolutely love it!! SUV started to occasionally hesitate when shifting out of auto stop. When this happens I get a check engine light. POAC4 and POBBD "Hybrid battery pack voltage variation exceeded limit" I am very new to Hybrids? Brand new to this site. Any possible causes. Would like to understand issue before a dealer tries to just hit me for a high dollar repair. Thanks!

 

It's a hybrid battery code.

 

 

Any thoughts of why might cause that specific code? Gas mileage is good. Caddy goes in and out of Auto Stop like it should.

 

Look for other codes and see if it fixes the problem. I had the unfortunate failure of my fuel pump at 188k miles. Code showed the fuel pump as well as the hybrid battery. Dealer erroneously replaced the battery when it was a fuel pump problem. GM corporate reimbursed me the cost of the battery thanks to hbh.

 

Thanks for your response. I have no other codes, but I did lift up the seats, and pull up the cover. Vacuumed out all the lint and junk around the HV battery. Then my wife took it to the store. She came back. Told me the Check engine light went out. So I went out and started it. No light. Could be a coincidence. We shall see.

 

2009 with 130k Miles....possibly Bad (or going/intermittently bad) cell(s) in the traction battery(300v). Very easy to test and replace yourself. Google "replace Prius Cell", there are several very detailed you tube videos, Same Panasonic cells and procedure Prius to Escalade, the Escalade just has more cells in the battery, Prius are more common thus more readily available info on testing and replacement.
Or you can replace the whole traction Battery for like $2500 your budget permits. They are supposed to last 10 years but its very common for one or a few cells to go bad.

 

I was afraid that it might be the HV Battery. I will have to check out the videos. I have been working on and restoring cars my entire life, but this is my first Hybrid. Thanks for the help.

 

 

Well the Check engine light came back on. POAC4/POBBD. Have a appointment At dealership this Friday. 🙄