2008 Tahoe Hybrid DRIVE MOTOR CONTROL MODULE and ACSRY DC PWR CONTROL MODULE programing issues.

[firedog3722]

I have a 2008 Tahoe Hybrid that is a very nice third car for my family. In the last 3 years it has had a refurbished drive battery installed, been painted, and the seats recovered and tires that are two years old. Very nice SUV.

Now the bad news. About 2 months ago the ACSRY DC PWR CONTROL MODULE went bad. Could get a new one from GM (PART 24251562) but they have shut off access to SI site required to program that module to my vehicle. On top of that you cannot (I couldn’t) get the gaskets required to install the module on the bottom of the DRIVE MOTOR CONTROL MODULE. Thought I was done.

I’ve worked with local Chevy maintenance guys for quite a few years and was told that if I could find one from another vehicle he thought they could get Tahoe running again. I found a complete DRIVE MOTOR CONTROL MODULE from a 2009 Silverado. It has the same part number and all we had to do was program the security module that is a part of the Tahoe.

Dealer installed the part and did what programing they could. They tell me that GM shut down the main site for all the modules involved. From what I read some of the other posts you can get to those using something besides a Tech2. Is that true?

Anyways, started the Tahoe and got a POBBD DTC, drive battery issue. Checked the battery, all battery measurements are with parameters, between 10-19V and 1.5 volts of each other.

Also got P061A and P061B DTCs. DTC P061B lists the POBBD DTC as a problem it may create. We think that is correct after checking the battery.

The Tech believes that PIM is not taking the programing, but no error during the load are presented to him. He is basically done and can’t go any further.

My question to this forum is “Do any of you know of programing tricks for the PIM? Do you have a copy of the last Download from GM SI site? Can you help me?

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please. If we can't see it, it does not exist.

GM does not allow programming from their site with the Tech 2 anymore. To program from GM's site, you need to upgrade to the newer programming format and bi-directional scanner.

 

[Fless]

Is your 'dealer' a GMC or Chevy dealer, or a third party? I would question the statement about GM shutting down the programming site -- one can still program previous gen modules using newer programming tools on the current GM site, as @Joseph Garcia noted,

It would be interesting to know if GM does not allow the programming of your modules.

 

[firedog3722]

After staying up last night a reading a bunch of threads, and talking with the dealer (Chevrolet) this morning, you guys are correct in that GM has turned off access to the site when using a tech2. I presented a bunch of the printed threads to my service contact today and he read through them. He said that is probably what a company called All Clear does for them. The dealer ship only uses a Tech2. My service contact told he had contacted them and is arranging for them to come try to do the programing. So Tahoe is not dead yet! They will have to use the steps to apply my vin the modules inside the the recycled Drive Motor Control Module (DRV MOT Gen Pwr Inv Module and the Acsry DC Pwr Control Module) and any other modules that talk with those, off the top of my head the module that does anti theft. Thanks to all off you that responded and to all the others in threads I read last night. I'll come back and let eveyone know the outcome once All Clear take a wack at reporgraming.

 

[firedog3722]

Now you can see it, so it does exist. The Tahoe 3 photo was taken after a complete paint job had cured enough to have a professeional ceramic coating applied.

 

[Fless]

I find it quite interesting that a Chevrolet dealer would not have and use the newer GM programming tools for later model year vehicles, calling in a contractor to do that work.

 

[j91z28d1]

dealers are all pretty horrible tech wise and older vehicles don't have any backside support to walk thru stuff. I don't trust a word any of them say.


I have updated the tcm in the tranny of my 2011 hybrid yukon a year or so ago just fine using acdelco site. Just cause I was updating a module in my volt and had the dongle and laptop out. figured I'd look to see if any updates were available.

at this point, if you have a laptop that matches the min spec acdelco website calls for. Just buy the 150$ dongle from OBDxpro gt. that's what I have, it works great and it's not a China cracked software. the developers are active in the message board pmc hacking. Com and thru email from the site.

the only module I know of any one having trouble flashing is the electronic brake controller under the driver side floorboard.

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also 1.5v different between hybrid battery modules is pretty bad if it was as rest not loaded. you might need to charge that if you can. if you can log the min and max voltage during a high current drain, you'll probably see a very large difference. before I rebuild mine they were all the same ish as rest but under load from driving and engine cranking min was 9 something volts while max was 13ish. soon after that it started bucking during transition from auto stop to engine power.

 

[firedog3722]

The diff between cells was only .04V. the 1.5V was what they told me would require a new battery. I put in a greenbeen 2 years ago. Watched a youtube on repleacing the cells and think I'll try that next time (if we get this on the road again) when it is required.

 

[BG1988]

I have a 2008 Tahoe Hybrid that is a very nice third car for my family. In the last 3 years it has had a refurbished drive battery installed, been painted, and the seats recovered and tires that are two years old. Very nice SUV.

Now the bad news. About 2 months ago the ACSRY DC PWR CONTROL MODULE went bad. Could get a new one from GM (PART 24251562) but they have shut off access to SI site required to program that module to my vehicle. On top of that you cannot (I couldn’t) get the gaskets required to install the module on the bottom of the DRIVE MOTOR CONTROL MODULE. Thought I was done.

I’ve worked with local Chevy maintenance guys for quite a few years and was told that if I could find one from another vehicle he thought they could get Tahoe running again. I found a complete DRIVE MOTOR CONTROL MODULE from a 2009 Silverado. It has the same part number and all we had to do was program the security module that is a part of the Tahoe.

Dealer installed the part and did what programing they could. They tell me that GM shut down the main site for all the modules involved. From what I read some of the other posts you can get to those using something besides a Tech2. Is that true?

Anyways, started the Tahoe and got a POBBD DTC, drive battery issue. Checked the battery, all battery measurements are with parameters, between 10-19V and 1.5 volts of each other.

Also got P061A and P061B DTCs. DTC P061B lists the POBBD DTC as a problem it may create. We think that is correct after checking the battery.

The Tech believes that PIM is not taking the programing, but no error during the load are presented to him. He is basically done and can’t go any further.

My question to this forum is “Do any of you know of programing tricks for the PIM? Do you have a copy of the last Download from GM SI site? Can you help me?

P061A/P061B is battery related P0BBD means the battery needs to be charged () most likely the battery needs to be replaced assuming the original battery from 2007.. it probably has less then 100mAh capacity left out of the 5.5Ah

 

[firedog3722]

P061A/P061B is battery related P0BBD means the battery needs to be charged () most likely the battery needs to be replaced assuming the original battery from 2007.. it probably has less then 100mAh capacity left out of the 5.5Ah

Third party programmer came to the dealership on Friday and got everything programmed but the new (recycled) PIM. He could not communicate with the module. Now the Tahoe won't even start. Does anyone have any idea why he would not be able to communicate with module? Do you now some back door method?

 

[j91z28d1]

the pim is the big inverter on the passenger side under the hood?

all I can think of is can bus wiring isn't correct. is it possible the truck hybrid had a different wiring the harness than the suv hybrid? you'd have to pull the wiring diagram for both vehicles and compare.


the car ran before it was programmed?

 

[firedog3722]

Yes the car would start and run for awile, then turn off. That was the reason to replace. The part number for the PIM in both vehicles is the same so I don't think there is a wiring issue but will check it out when I get both wiring diagrams. Thanks!

 

[j91z28d1]

how long would it run? I only ask because these things crank the engine with the electric motor inside the transmission, and it sounds like 1200 rpm the engine is running. it trys to start for about 15-20 seconds and stops. I've heard it myself and it sounds like a running engine, but it's not. not that it really matters. Just curious.

only reason I bring up wiring is because module like say a body control module, same part number in many different cars and the inputs and outputs can be different based on how that car is wired and needs those internal inputs and outputs are used. it's a long shot thou.


if it won't crank at all, there's so so many reasons these won't enable cranking, it's like their default is depowdered for safety. might need to run a full module scan of everything, there's also a accident disable that can get set in many ways accidently, scanner rest. and I have heard a theft one in there. but I've not found that one. Last hope is pull the battery cables off the 12v battery and hold them together for a good 30secs or so. sometimes that works wonders on these gm trucks and suv's for some reason.


if you can't find anything in a scanner anywhere about inhibitiing cranking and all covers are installed everywhere. there's interlocks on all of them, even the plastic cover over the pim has an interlock in it. it won't close the contacts in the 300v battery without it.


just stuff off the top of my head. there's so many things, like one guy bought one the engine had been replaced because of afm lifter failure. it just randomly dies after a year or so, 6 months of troubleshooting and it turns out the shop that did the engine swap used pag ac oil instead of poe. over time pag can become slightly conductive and the system fails the key on 300v insulation test. he replaced the ac, even thou gm has a flush tsb about it, since it's common on all electric ac compressors. and bam, it fired right up.


stick with it.. good luck and I hope you figure it out.

 

[RussellZ]

I bought a dead 09 Tahoe hybrid a couple years ago for a song, vehicle wouldn't start but was in nice shape otherwise. Had been to the dealership and they couldn't figure it out. I hooked my tech 2 up and found that the GMDCM was not communicating. I assumed the GMDCM was shot and bought a used one like you did from same year / make / model. After swapping the replacement in, I was able to communicate with it but it tossed a bunch of battery related codes and wouldn't start. I used techline connect and a drewtech mongoose GM2 to try a security relearn but it failed. I re-flashed the GMDC with the correct programming and it appeared to be successful but the same issues persisted and a 2nd security re-learn attempt failed as well.

I swapped the original unit back in and thought it looked oddly new so on a lark I tried flashing too. To my surprise, it took the programming and I was able to succesfully perform a security re-learn then the vehicle started. I suspect that the original GMDCM died and the dealership replaced it but didn't flash it for some reason. I think that they get VIN locked and cannot be re-flashed and security re-learned to use them in a different vehicle. You may need to track down a brand new GMDCM or find someone who can clear the VIN data out of your used one and prep it to take new programming and a new VIN.

After getting the GMDCM working I then found that the power steering was not and after some diag I found the PIM was not putting out 42V for the PSCM so I swapped the used PIM from the GMDCM I'd bought used onto it, flashed it and then the power steering worked as well. Putting two and two together, I assume that the PIM died and took the original GMDCM out with it. The HPCM was then fault free and worked properly.

Unfortunately, the engine always had a bit of a miss and clattered quite a lot and it had a bad engine oil leak off the back of the oil pan dribbing off the aux transmission oil pump so I never drove it. I recently decided to do a solid axle swap on it to use it as an offroader (becuase why not?). I swapped the rear diff out with one from an H2 and bought a front SAS kit and a 2010 Ram 2500 front diff. After I cut the front suspension and crossmembers out and had easy access I dropped the oil pan to deal with the oil leak and I found the timing chain tensioner in the sump. I popped the timing cover off and found the chain was super loose, amazing it didn't jump a tooth kind of loose. I put a new timing set into it with a newer ecotec timing chain tensioner (I couldn't find any reports of them failing like in the gen IV engines) all excited thinking I'd found my clatter and misfire. Fired the engine up and was presented with an awful screech coming from the crankcase. Dropped the oil pan again thinking maybe the crank was rubbing on the windage tray but it was fine. Checked all the rod bearings and found they were far from great but still okay. Pulled the main bearings and found that main #2 had a very deep gouge in the bearing and the crank shaft is badly scored. Do'h!!

Now to decide if this $2000 truck that I'd already put lots of hours and money into is worth replacing the engine in or not. It's in decent shape otherwise. I might part it out, scrap the body and keep the rolling chassis to put under a LZ1 Escalade or something instead. A used engine is $5000 around here with 200k miles on it and you can buy a complete running/driving rig for $7000 with less mileage than that.