Hi all, first time poster here. Hopefully someone can help me figure out what's going on before I go back to the shop...

I bought this truck brand new in 2005. I put 135k miles on it since - mostly commute driving, which is has been 20 miles of highway, each way. There has been some boat pulling with it, as well as some long road trips. The truck was in Florida and south Carolina most of it's life, very little cold weather until this winter.

I haven't really had any problems with it, it's been a great truck. I had the hybrid computer replaced at about 40k (warranty) and hybrid batteries replaced at about 75k (warranty).

last week, the truck began idling really rough...enough to shake the truck in idle. It was also hesitating when gently accelerating at around 40 mph (~1k on the tach). I took it in and they claimed carbon in two plugs, replaced the plugs and plug wires, and cleaned the throttle body. great, the idle issue is fine. I just got the truck back on Thursday (2 days ago).

Here's the problem: since then, when the engine shuts off at a stop light or whatever, it's had trouble kicking back on. The "low oil-pressure sensor" light pops on, and she won't start. If I put it into park and use the key, she fires right up but she has had trouble firing up on her own.

What am I looking at here -

is this a symptom of the cold? The number of days I've driven this truck where the temp never got above freezing is less than 5, yesterday being one of those days.

Is this a symptom of the bank of batteries under the back seat being on their way out? that's my fear - the last needed replaced at about 75k, and these have about 60k - getting close to EOL, I suppose.

could the mechanic have messed something up while they were messing with the carbon deposits in the throttle body and plugs?

I suppose I don't mind buying new batteries because I've actually spent very little on this truck maintenance wise over the past 8 years. I just put on the 3rd set of tires and bought the 3rd battery - I fully intend for this truck to hit 200k+, but not if I'm about to see a ton of other things go wrong.

Thanks in advance for any replies!

 

sounds like a fuel filter issue to me. but have them check the batteries.

 

What turned out to be the culprit?

 

hello, I was wondering if you replaced the hybrid batteries yourself,​ or if you had a dealer do it I recently bought a set of hybrid batteries for my 2005 silver ado and was wondering how feasible it is to replace them yourself.

 

Did you ever figure out what was wrong?

Currently having similar issues with my 2013 GMC Sierra 1500 hybrid ~186kms

 

Start a new thread the 2013 is different then the 2005 which used lead acid batteries IRC

 

Yeah not really a Hybrid vehicle it just has the early version of the "Start/Stop" system possibly has a bad start/stop control module.