V1 How to read BCM/ECU pin layout?

[Mayor West]

I know I've seen the pin structure somewhere, but I can't seem to find it anywhere now. I'm trying to load up on electrical docs and store them in my google drive for myself and others to use (see signature) and this is something I'm currently in need of now as I diagnose my starting issue.

Basically, how are the wiring diagrams related to the physical pin layout themselves? Now that I've thinned out all my harnesses, it's sorta difficult to 100% confirm the layout and orientation when trying to trace wires using a wiring diagram.

Take this example of a BCM layout:

It's numbered 1 through 72, then X2. Other than visually mapping the colors to the pins (which is what I'm wanting to avoid since I've thinned everything and there's the occasional re-spliced wire that's not the original color due to my mistakes/learning)

I want to test continuity between a few lines but I want to disturb my harness as little as possible to prevent possible further issues (I did this myself so it's probably hanging out by a thread)

Where does everything land on the harness?

I have a similar one for the ECU but it's not really helpful for the BCM.

 

[Briann1177]

There really is no relationship between the physical layout of a connector and the wiring diagram.

What I did was found a string of pins that have wires on them, took note of the colors, and then located them on the wiring diagram. From there you can get the pin locations and then you have a reference point based on the physical connector picture.

Hope that makes sense.

 

[Fozda]

All of my connectors had really small numbers running down the side to use to figure out the pin location number. Do yours not have them?

 

[Mayor West]

There really is no relationship between the physical layout of a connector and the wiring diagram.

What I did was found a string of pins that have wires on them, took note of the colors, and then located them on the wiring diagram. From there you can get the pin locations and then you have a reference point based on the physical connector picture.

Hope that makes sense.

The ECU has this mapping (pictured above) but the bcm doesn't? I'm hoping that's not true.

All of my connectors had really small numbers running down the side to use to figure out the pin location number. Do yours not have them?

I think the ECU does but not the bcm. See the pic for the inside. The plug itself has nothing on it either.

 

[Ross]

I see all the 4 connector views for the BCM for my 06 LSJ.
Not sure if these changed for your donor BCM.

 

[Gtstorey]

I've been using the circuit numbers to trace it from the connector to BCM, ECM, etc. My engine was harness was in pretty bad shape and I went through it and checked continuity on all of the connections. It's a little harder on the Body Harness since you really don't know where it may trace to on the other end. If you have a question about where a pin goes you have to look through all of the connectors pin outs for that circuit #.

I guess wiring diagrams have gotten too complicated to work anymore.

 

[Mayor West]

Ross, that AllData info is basically what I need. I know it's for a different year/model but I'll still save them for reference. I try not to look at your subscription too much incase I go down t he wrong road given the model/year differences, but this time I'll take a peak for sure.

Even if it's just partially right, if I can figure out the pattern I can probably make due.

Thank you!

 

[Mayor West]

I went ahead and got a AllDataDIY subscription for my 09 SS/TC so I could be 100% certain, only 20 bucks for a year... well worth it given the issues im having. For what it's worth, here's the pinout for the BCM.

 

[Ark :D]

Stolen, shamelessly and without regret, because my AllDataDIY subscription SHOULD have had those included. Thanks MW.