I had these symptoms years ago, but they went away. Now it is similar to what the wife is reporting. Before, it was only on really hot days and I could tell by the way the engine was not shutting off much, that the Hybrid Battery was empty. I have an early '08 and never had the snap ring issue or any pump issues at all. I'll get to the bottom of it...

 

A HV battery that is too warm will cause the engine to stay out of Auto-Stop too. Anything on the floor in front of the long horizontal battery cooling inlet slots?

Since it is getting up in miles you could check the "cheese grater". The actual expanded metal air inlet to the HV battery. It is on the driver's side under the plastic and carpet trim cover.

Lint, dog hair, etc can build up and restrict air cooling flow. Just one thing to check off the list of items to look at.

 

I purchased and 09 Tahoe ( build date 08/08 ) and have begun having very similar issues. Hesitation when first put in drive, chugging from a stop, and lurching when switching from engine to electric mode. Gear shifts while driving are also noticeably more pronounced. No codes stored and no lights. Dealer says they are unable to replicate the issues and the shifts feel "ok"..I could never feel them at all before. Sigh. Good news is I have about 99k miles and my warranty is about to expire. =p

If anyone stumbles on some answers please let me know.

 

is there an easy DIY to clean the 2nd row battery? I don't want to be zapped.

 

If you want to inspect and clean the air inlet, just do it. As long as you do NOT open the HV battery case (this requires tools to remove bolts )there is nothing to zap you. If there is build up of lint, dog hair, fuzz, etc, it can be puled off like the lint in a clothes dryer filter. Or a plastic shop vacuum nozzle can remove any build up. Now be careful getting the large plastic and carpet cover open. There are lots of plastic and spring clips, some may break. Same going back on, good alignment is needed. This will allow you to see the air inlet. ( cheese grater ) and vacuum up anything that may have gotten in through the long horizontal inlets on the floor in front of the HV battery.You drive yours alot so looking for mouse evidence is probably not needed. The air outlet like the air cleaner on my Suburban seem to be attractive to them. They better not chew up my new K&N filter.

 

Hello.do u still have the truck? If so how many miles ? If not any thing you might want to say about ?

 

Yes, I still have it, and it works great. Hot days I still get the issue. A month or so back, I cleaned the "cheese grater" and also took apart the hybrid battery, since I know what I'm doing. The grater was clogged, but really nothing past that. I was really surprised, even the blower motor and exhaust was clean. The battery itself was pretty much spotless. I don't understand it. Anyway, when I did it back in late January, it was really hot for a few days, so I cleaned it, but have not driven it on a hot day again. I really don't drive it much, my AuPair does. My wife has a 500e and I have the Volt...

 

Seems like people that bought these keep them for a long time.how many mm Iles are on yours? Any tips to follow to get the most out of it ?

 

Proper maintenance and drive it a lot.

 

Hi all, not sure who the question was directed at, but since I started the post and have been woefully absent from it, I'll give an update. I'll just say, we've put a bunch of miles on it, of late. I think it's mostly from driving around town. I'm at about 105-110K.

May have mentioned on another thread, but prior to 100K warranty expiration, I combed through the different posts and found the link to the auxiliary pump fix, that GM mentioned. Can't remember the exact wording for how GM posted.....it wasn't a recall. In any case, I already had that aux pump replaced, but asked the dealership to take a look at the part and make sure it wasn't the original type of aux pump mentioned in the GM memo, because then it would be getting ready to go out again. Turns out they replaced it with one of those. So, got the newer model aux pump this time around. Too early to say if it's "fixed".

I say I'll keep this post updated, but somehow it usually is only when I've got an issue. Even with this main issue, once we found a dealership with a good agent (not a salesman), it's been a fun car. Their approach was good in that they relished the opportunity to get some man hours on the Hybrid.

It's probably nearing the time when I'll start having to invest some money in it, or think about selling. Small oil leak, Hybrid battery life ($3-11K replacement cost??), 105K tune-up, new tires, etc. Plus I still haven't made the time to reroute the exhaust and put the spare in. Oh well.

I'm hoping to hang on to it for a while longer.