Tow-Haul Mode - PCM connection?
04-01-2004, 02:51 PM
#11
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Hmmm, there's no connector shown for the BCM, just where it fits in the wiring diagrams. It shows that the tow/haul switch input signal to the BCM is a light blue wire that goes into pin B12 (connector C1) on the BCM harness. The PCM harness connector shows the serial data bus as the only connection between BCM and PCM.
04-01-2004, 05:36 PM
#12
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Hmm... my BCM has a little 6-pin connector
for C1 and C2, and the big one is C3 - with
the B row and E row (topmost and bottom-
most, they call the 2nd row C and the 3rd
row D) unpopulated. My C12 is "Security
Indicator Control" and D12 is "Right Front
Door Ajar Signal Switch"
I scanned my connector pinout pages from
the Helm manual, curious about how (if) the
connectors match up, yours vs what's shown
in the attached .pngs
Is your B row the top row on the connector?
Are your 2nd and 3rd row the "main bundle"
and this B12 is kind "off by itself"?
Or maybe the trucks just have a way different
BCM
Thanks for doing all this "legwork"....
for C1 and C2, and the big one is C3 - with
the B row and E row (topmost and bottom-
most, they call the 2nd row C and the 3rd
row D) unpopulated. My C12 is "Security
Indicator Control" and D12 is "Right Front
Door Ajar Signal Switch"
I scanned my connector pinout pages from
the Helm manual, curious about how (if) the
connectors match up, yours vs what's shown
in the attached .pngs
Is your B row the top row on the connector?
Are your 2nd and 3rd row the "main bundle"
and this B12 is kind "off by itself"?
Or maybe the trucks just have a way different
BCM
Thanks for doing all this "legwork"....
04-01-2004, 05:51 PM
#14
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Originally Posted by jimmyblue
Hmm... my .png attachments don't seem to
show up, but they look like they went. How
'bout .gifs?
show up, but they look like they went. How
'bout .gifs?
04-03-2004, 02:34 AM
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jimmyblue, not an April fools joke. Sorry it took me a while to get back to this.
I looked harder in my manuals and finally found the BCM connector. I don't have a scanner handy, but I can tell you a few things...
Again, this is from a 2000 truck/tahoe/yukon service manual.
The BCM has 3 connectors - 2 24-pin and 1 16-pin. The pin assignments don't appear to exactly match yours in any particular fashion.
The tow/haul switch input signal (pin B12) is the last pin, bottom row on that connector. B11 = seat belt switch signal, B10 = park brake switch signal, etc.
Position-wise, pin D16 on your connector is the closest match, but since none of the others seem to match that probably means nothing... like you said, the truck BCM is different.
I looked harder in my manuals and finally found the BCM connector. I don't have a scanner handy, but I can tell you a few things...
Again, this is from a 2000 truck/tahoe/yukon service manual.
The BCM has 3 connectors - 2 24-pin and 1 16-pin. The pin assignments don't appear to exactly match yours in any particular fashion.
The tow/haul switch input signal (pin B12) is the last pin, bottom row on that connector. B11 = seat belt switch signal, B10 = park brake switch signal, etc.
Position-wise, pin D16 on your connector is the closest match, but since none of the others seem to match that probably means nothing... like you said, the truck BCM is different.
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