I stumbled upon a left for dead 09 Hybrid Silverado for $1500. 6.0 was dealer replaced 60,000 miles
ago, truck has 128,000 miles on it now. Currently my Xtool reads the hybrid battery at 305 Volts, it has been sitting since the fall.

I've been searching forums and reading about similar codes. I'm going to disect the wiring and look for rubbed wires/pushed pins. I did stumble upon a post that suggests thr hybrid control module is shot though.

https://electricvehicleforums.com/forums/gm-hybrid-trucks-cadillac-escalade-hybrid-chevrolet-tahoe-hybrid-gmc-yukon-hybrid-69/2010-escalade-broke-down-32607/

If that's the case I don't want to waste all my time.

Does anyone have any input otherwise? Also what is ths healthy voltage of a hybrid pack? All the cells seem to have similar balance. One of the invoices with the truck states it needs a new Hybrid battery though.

 

Update.. the positive battery cable was loose down the line. Recharged battery, rescanned, cleared DTCs and I'm left with only 1 screen of codes now.

 

Update: Truck runs!!

Checked a bunch of connections and wires following a TSB related to codes I had. Turns out that was a waste of time.

I ended up finding the 300V reset function on my D8 XTool, after that was reset I was able to clear the HPCM code. Note: This was separate from the crash sensor reset, wasn't an issue for me there.

Once the hybrid module was reset I found the jump assist setting in my scan tool. Hooked up a 12V 40a charger and charged for 2-3 hours. That was all it took to wake the dead truck up!

Now I am left with electronic brake control module codes. I tried doing a EBCM recalibration earlier and I think I really messed things up. So.. that'll be next. But at least it runs.

So for anyone else spending hours searching why your GM hybrid won't run.. Remember, make sure you have a fully charged and healthy 12V battery with good connection. If it was discharged, unhooked, or previously boosted you may need to reset your 300V system using an advanced scan tool. XTool D8 is what I have.

If the vehicle was sitting, or depleted with the ignition left on you may need to jump assist the hybrid battery. This is not like boosting a 12v battery. It requires a minimum 20amp continuous charger. The system will have to be placed into jump assist mode with scan tool. Afterwards the hybrid battery and motors will be energized to start the ICE engine once again.

Hope this helps someone out there.

 

This one sounds like it has had a lot of wrenches turned on it for such a low mileage unit but hey at 1500 bones still a deal if the interior is good and it is not wrecked or something.
I had some problems with the ABS on my 2009 at around 250k miles and I ended up having to replace the ABS system. The root cause was the brake fluid was dirty/contaminated and clogged up the ABS. Best to flush the braking system every 60k miles or so from what I understood. I was about 4 times that recommended interval LOL.

 

That's really good to know. Thank you! I'm still stuck with no power brakes. 128,000 miles on it. 3 codes ( C0242 C012E C0561-4B ), I've pulled and inspected the ebcm and no visible corrosion. But I wondered about flushing the system since it sat.

Probably good to do it anyway. I know a GM mechanic that works on the side, he did some looking and there is an updated file for my ebcm. Sometime next week he will try reprogram it and relearn with dealer procedure. After that I'll start replacing parts.

 

Yeah unfortunately on mine the damage to the inside of the ABS was bad and it could not be saved. The ABS is a J92 system 7700lb active brakes the ABS unit is not available (obsolete) if you need one you will be looking at a salvage yard part. I went back with Dot4 synthetic fluid thoroughly flushed the system hoping that it will last a few years now.

 

Literally what my problem is right now for my '09 Tahoe Hybrid - Dealer diagnosed it as bad Valve and ABS Brake Controller. Went thru hell and back but was able to find *NEW* parts. The Valve was the easy part but the Brake Controller was hard to locate - I think I found one of the only 2 left in existence (now only 1 left). Summit Racing (https://www.summitracing.com/parts/ado-84078739). Mine arrives Tuesday. Been down 3 weeks trying to find parts.

Almost went certified used (12 month warranty) if I couldn't find the parts. https://carpartsource.com/products/2...parts_car_8275

 

I replaced the control module first and it worked for a few months. Thought that I was all good but NOT. I had to replace the entire assembly and it has been good now for a couple of years. Ole TaHOe is a lot of trouble at times but I like her LOL
I did have a recent unrelated brake issue, About 2 weeks ago on the front passenger side the brake caliper was not fully releasing (sticking) and it was a bad brake flexible hose. Went ahead and did both sides it was easier than I expected and only about 14 bucks each from rock auto for the OEM GM brake hoses that fit perfectly. After researching a bit apparently their is an approx. 6 year expected life for brake hoses?
Once I hit the Lotto i will just buy a new vehicle each year Hahah

 

This solved the issue - dealer finished the install (had a brake bleeder that snapped off so had to purchase a caliper), but now with everything buttoned up, been working fine for over a week. Just glad I was able to find the parts!