LB7 stand alone harness questions
- Thread starter buick455
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Nope, my swap ran for almost 6 months with no BCM in it. I only added a BCM because I wanted tow/haul mode.
For how I did mine it was. I know at one time BT was offering a way to activate it without a BCM.
I'm getting conflicting info from Alldata vs my Haynes manual. The Haynes manual says ECM C1 pin 33 is for crank voltage but the Alldata ECM C1 pinout shows pin 33 is not used and I haven't found it in any Alldata diagrams. If it is being used where does it go and is it sending power out, receiving power, or grounding?
yes, depending on wether it is an auto or manual it should have some minor differences. see the pinout on the one I posted, it shows both versions on the pin 33. also don't forget pin 34 for the park/neutral signal. it will need this input before it will send power out to the starter on C2-4
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Looking over the pinouts you posted in C1 pins 8 (blank on my diagram and in my truck harness), 24 (blank on my diagram and in my truck harness), 37 (shows inj 6 on your pinout and inj 5 on my pinout) and 44 (shows ign voltage 1 on yours and inj 3 on mine). On C2 pin 2 on my diagrams it shows empty and on my truck harness it's also empty. This doesn't make me very comfortable when diagrams don't match on very important items lol. Can anyone verify these? I'm using Alldata that I subscribed to and a Haynes manual and they both match pretty well.
from what I know, the ECMs for all years of the LB7 are the same. the only difference would be the pinout for the oil level sensor and the difference shown for the manual vs auto signal. the rest I would think is the same.
the diagrams I posted ate from GMUpfitter.com and has always been reliable for me and others as it comes straight from GM. I have no idea of the source or reliability of other providers. but I may be wrong and there may be differences. I would wait and see if anyone else has any insight on this
the diagrams I posted ate from GMUpfitter.com and has always been reliable for me and others as it comes straight from GM. I have no idea of the source or reliability of other providers. but I may be wrong and there may be differences. I would wait and see if anyone else has any insight on this
01 LB7 ECM's are different from 02-04. 01 doesn't have the circuit to read oil pressure iirc, no egr ability, and had some internal differences as well as operating system differences(hence why if you flash an 01 ecm to an 02 OS and then back to an 01, it permanently corrupts the change engine oil segment leaving the message on all the time). But the pinouts are the same as far as I know.
that's what I was thinking. do you have any explanation for the discrepancies between the different documents posted above? I've always found GMUpfitters to be reliable bit have never used Alldata or any others
I grabbed a pic of my 2003 GM service manual. It seems to agree more with the Alldata screen shots, in terms of the C1-37 and C1-44 discrepancies the OP pointed out. However, I did note C1-33 shows "crank voltage" in my book vs. Alldata saying no connect.
In the transmission chapter, I looked up the ZF6 related connections to the ECM in my manual - only 4 called out on this schematic page: C2-20/C2-21 VSS speed sensor, C1-35 clutch switch, and C1-58 class 2 serial data.
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In the transmission chapter, I looked up the ZF6 related connections to the ECM in my manual - only 4 called out on this schematic page: C2-20/C2-21 VSS speed sensor, C1-35 clutch switch, and C1-58 class 2 serial data.
<edit - added larger size pic>
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Thanks for the replies. I may have to look at the pin locations and wire colors of the oem truck side harness to see what matches which diagrams. I wish they had actual "system" diagrams instead of just small sections. I have to bounce around like crazy in the Alldata stuff.
Alldata gets there diagrams straight out of the GM service manuals and have found virtually no differences between alldata and my GM disc.