V1 Electrical start issue

[DRL]

I went back a reread this post. Is this correct? The engine wire harness is from an N/A motor? The fuse box and the rest of the wiring is from an SS?
Engine wiring harnesses are not usually interchangeable between engine sizes. This stuff changed almost yearly. An SS engine harness has circuits an N/A motor does not have. Intercooler pump, VVT?, a second cam sensor, A mystery sensor by the turbo?(Mystery to me! I know one is there that is not on any N/A motors harness), etc.
Compare the wire positions on the big black block connector on both harnesses and make a chart of the connector positions on each(note wire color and size). Each row down is numbered and across is lettered. Holding the block in your hand the letters/numbers are molded into/on the side that the wires go into the block, not the face that connects to the fuse panel bottom. The numbers/letters are very small, use a magnifying glass if needed.

Thank you but the fuse block, wiring, BCM, ECM are all from the same non-SS

ignition, pedals, instrument cluster from SS but best I can tell interchangeable

 

[DRL]

Update:
I’m getting 12 V in all BCM connectors and good ground at all BCM/ECM connectors. I’m getting 12V at OBD.
Grounds are good at all ECM/BCM connectors
Fuses all good

I am NOT getting any voltage at 5 volt reference pins:
BCMX2-18
ECMx1 66 or 67
ECMx2 13, 33-35, 53-55
(I don’t think BCM x1 63 or 64 are pinned for me)

no crank. OBD not connecting.

 

[DRL]

I didn’t back probe. Measured 5V with plugs disconnected. But was getting 12V in same manner. Do 5V need to be back probed with connector plugged in?

 

[Gtstorey]

Need to post the wiring diagram to be able to accurately answer. All of the pin information that you are giving doesn’t mean anything without it unless some takes the time to look it. And I can’t even remember what parts are from on this Frankenstein.

 

[DRL]

Need to post the wiring diagram to be able to accurately answer. All of the pin information that you are giving doesn’t mean anything without it unless some takes the time to look it. And I can’t even remember what parts are from on this Frankenstein.

Apologies. I am struggling to understand wiring diagram myself. For example I am seeing pin 18 as 5-volt reference so assuming I need 5V. But I can’t find circuit 5359 on wiring diagram. Maybe you can point me in the right direction of how to search the wiring diagram.

 

[Gtstorey]

What did you mean when you said obd now won’t connect. A ode reader won’t read? Does it power up?

Beyond that you need to look for something along the lines of a starting schematic. Probably in the engine electrical section. You are going to waste to much time just checking everything on the connector to the ECM and BCM since you don’t even know if it’s a circuit related to the cranking. But if you want to check them anyway you need to back probe with them connected since you don’t know if you are measuring a feed or a s “signal”.

But a way to track down a particular circuit number is to look through all of the pin outs for the other connector and see if you can find the other end.

 

[DRL]

What did you mean when you said obd now won’t connect. A ode reader won’t read? Does it power up?

Beyond that you need to look for something along the lines of a starting schematic. Probably in the engine electrical section. You are going to waste to much time just checking everything on the connector to the ECM and BCM since you don’t even know if it’s a circuit related to the cranking. But if you want to check them anyway you need to back probe with them connected since you don’t know if you are measuring a feed or a s “signal”.

But a way to track down a particular circuit number is to look through all of the pin outs for the other connector and see if you can find the other end.

What did you mean when you said obd now won’t connect. A ode reader won’t read? Does it power up?

Beyond that you need to look for something along the lines of a starting schematic. Probably in the engine electrical section. You are going to waste to much time just checking everything on the connector to the ECM and BCM since you don’t even know if it’s a circuit related to the cranking. But if you want to check them anyway you need to back probe with them connected since you don’t know if you are measuring a feed or a s “signal”.

But a way to track down a particular circuit number is to look through all of the pin outs for the other connector and see if you can find the other end.

I have a Bluetooth OBD reader. It will not connect to my phone. It worked last week briefly (only when headlights were on, likely a back feed). Now that I fixed the battery connection It is no longer connecting.

I think you are suggesting I test for continuity of all the connections on the starting diagram. Test relays if present. Is this diagram a good place to start.

apologies if I am not understanding a fundamental basic

 

[Gtstorey]

There is much more to electric testing than just continuity. Are you getting voltage where and when you are supposed to? Can those circuits actually carry amperage if they are seeing voltage. And then if you find a problem you have determine if it is a direct problem with the wiring or if some of the logic within the computers isn’t being met or transferred.

You have a steep learning curve to go from struggling to read wiring diagrams to troubleshooting a modern vehicle.

And you also have to worry about the theft deterrent/immobilizer stuff and various safety cutoffs.

And if your code reader stopped connecting you could be back to a problem with the data wires. Or it could be a power or ground issue a the obd connector.

I did find you circuit 5359 as being the 5v reference to the brake pedal position sensor. So that should be 5v supplied by the BCM.