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sent the thing off a few weeks ago that sounds real promising
to getting this done
Perhaps there is another source after all.Will update when I get it back
Got the BCM back from getting the work done that was needed
seems to be working but the XM unit is still locked Grrrrrr
Im guessing it was from a different vehicle than radio.
I can send the module out and have the VIN wiped so may need to do that.
so end result is there is someone that can do work on BCM reasonably and reliably PM me if you want more info
edit just tried my MP3/I POD input thru the XM selection on radio and it works!
maybe the locked message Im getting is due to no subscription. Any input from TB SS owners
if this is true?
XM is coming up as "LOCKED" which Im told is due to VIN not matching the BCM or the Radio. So I was lied to when I bought this system as all components werent from same vehicle. I questioned why the junkyard paint marker was all over everything except the radio and guy just blew it off.
So Im now going to experiment with the XM module with the theftlok chip hack.
So far the BCM reprogram is working fine. So much for those that said that cant be done either. Thanks Westers.......
stock 4.3
I know its in the BCM because Ive swapped BCMs out when I wanted to add things like fog lights and tow/haul.
Have any idea what the RPO code is for tow/haul?
We have added tow/haul to numerous cars, we used to use it for different shift points on nitrous. We added (1) wire to the harness and momentary grounded it to activate. The tables are in the pcm for tow/haul already just have to adjust them. Never flashed the bcm on any of them.
S10 blazer is different
I have the entire vehicle already set up with factory harness button etc
it works when I swapped BCMs with one that had this as a factory option
looking to do this on my BCM so need the RPO code that was for tow/haul.
when you do it your way its sidestepping the BCM.
BCM commands PCM to go into tow/haul mode.
Are you talking about a blazer with a 411 pcm, red/blue connector? If so you will give pin C1-71 a MOMENTARY Ground to activate T/H. You will also need to change all the T/H (performance in efi live) shift points and pressures since they are the same as normal shifting in a blazer or any vehicle that didnt come with T/H. The BCM may control the dash light BUT it does not control T/H in a 896/411 pcm. This is how GM does T/H in a factory truck with T/H by grounding C1-71. If you have a L31 (black pcm) and you dont have a 411 pcm then disregard, I dont know how they do T/H/.
well I can tell you for a fact that when you use a factory harness and ONLY change the BCM to one that's programmed for it,tow/haul works just the same as one that was factory OEM. Have done this to several by just swapping the BCM. Shift points are changed etc just like it should be.WITHOUT changing anything in the ECM.Again...BCM tells PCM to go into tow/haul mode AND turns the light on.
Changing BCM won’t change the tables in the tune in the pcm. The 3 s10 tunes I just opened all had the shift points and line pressure for Norma and tow haul. Pm or post the vin to one you did and I’ll check the factory tune and see if it’s any different than the ones I have. These were 2002’s I tuned.
If all of the 02s you did had dual tables and all the ones Ive tried(3 also) have successfully converted to tow/Haul then I would say theres a good likelihood that
the 4.3s all had the dual tables for tow haul.
I know for a fact these worked just like the factory ones as I also own full sizes that have this. But we have gotten nowhere on figuring out if it can be added to an already programmed BCM(similar to adding fog lights).I still need the RPO for tow/haul to see if the tech 2 will allow it to be added. thanks for the interest
You misunderstood, the tables for tow/haul and normal are the exact same, essentially meaning even if you swap bcm's and tow/haul works it still wont do anything since the same values are in both tables. The tow/haul tables (performance) are in everything tune, some are zeroed out and some just have the same values as the normal shift points if the vehicle doesnt use tow/haul. The BCM isnt going to change the tables in the pcm. The pcm will still need to be flashed even with a bcm that has tow/haul enabled.
I did look up how the factory s10's do tow/haul, the button is going to the bcm to activate tow/haul. When I add the wire C1-71 I change a table in the PCM that tells it to use PCM only for tow/haul vs looking at the bcm to activate tow haul in the pcm.
I just looked at every RPO and none show anything resembling tow/haul that I could find. You could try CF6 or Z82 but they are my best guess. I have programmed alot of BCM's in vehicles changing all kinds of options but have never seen anything about tow/haul, but I have never specifically looked for it either. I can bench flash BCM's also but only have the harnesses for about 5 part numbers and there are alot of different bcm's out there. I also wouldnt have a way to test if that added tow/haul. If you had a VIN off one with factory tow/haul I could probably figure out the rpo, it has to be part of some package not related to towing is my guess.
yea kicking myself for not saving the VIN for the ones I ve plucked out.
I'm guessing that GMT wouldn't be the same ,those are pretty common
and I do have a couple of them.
OK just went for a test drive
03 S10 Blazer 2WD did not come from factory with tow/haul.
Swapped in a BCM with one that did come factory equipped with tow/haul.
DID NOT touch the PCM. connected my scanner(MT-2500,which is bi directional)
in trans table 1 it shows tow/haul and selection with button coincides with the tow/haul light on dash.
when tow/haul is selected with button shifts are most definitely firmed up and shift points elevated. Holding throttle steady at 40 MPH deselecting tow/haul,it will upshift.
selecting tow/haul will drop it down a gear as seen by the tach and gearshift selector.
this is not just turning a light on it is running another program in tow/haul just as it should...again SAME PCM. If and when I get a copilot that knows how to read my trans tables I can get more info. SOP tells me its working as designed just by changing out the BCM.
I'm sorta stuck now as the OEM BCM will no longer relearn security code so I can start with it.Whats odd is I got another BCM same cal codes and it wont relearn security either but can swap this BCM in that's got the tow haul and it starts right up. Tried to force a relearn with TechII but no go.I would just keep this BCM in as its got factory fogs like mine does but airbag module isn't happy with this one.
You are correct and I was wrong on the shift points being different. I just opened up a 2003 and the tow/haul (performance) had different part throttle shift points. It doesnt modify line pressure just shift rpms. I dont know why the 3 I opened were the same unless they werent stock when I tuned them. I didnt have access to all the stock GM tunes back then like I do now. Its been years since I tuned any older s10's. Here is a pic of 1st gear shift tables from a 03.
thanks for that
sure feels like line pressure is increased
again I need a copilot to read my snappy
and see what differences it has
I think the SRS module is a once and done like the BCM is on VIN
its due to mismatch of VINs from one to the other.
04-07-2015, 09:16 AM
