No, The connection at the battery with the 50 amp fuse powers the BCM directly. The connector at the fuse box you are pointing to is for the power steering.Ok, this may be a much easier fix that I thought, if my memory serves me well (probably not!) ... but the connection right after the 50A fuse near the battery leads to the pictured connector on the fuse box, right?
View attachment 14918View attachment 14919
Yes, they should have continuity. Power from the battery to the inline connector. From the inline connector to the inline 50 amp fuse. From the fuse to the BCM1 input (BCM X3 D4) as shown in your picture. This powers many of the circuits at the BCM. This would NOT cause an issue with power at pins 3, 5 and 6 as they are powered from the main fuse block.
Now I am confused. Both the text in one of my previous posts and the BCM layout I provided in post 507 indicate exactly what you think - pin 56 should get power from the BCM1 circuit which in turn gets power from the large red wire feeding BCM X3 D4. What I had mentioned before is that the power for the large 3 wires at X2 on the PCM get their power directly from the fuse box. Hopefully this helps, if not, let me know.My wire tracing says that pin 56 in the ECM connector winds up in the red BCM plug and pulls power from the large red/black wire in the corner. You're saying otherwise, so you're probably right. My head is spinning with the wiring right now.
Now I am confused. Both the text in one of my previous posts and the BCM layout I provided in post 507 indicate exactly what you think - pin 56 should get power from the BCM1 circuit which in turn gets power from the large red wire feeding BCM X3 D4. What I had mentioned before is that the power for the large 3 wires at X2 on the PCM get their power directly from the fuse box. Hopefully this helps, if not, let me know.
Take a look at my diagram in post 507. You will see that the BCM is actually divided up internally into 4 major circuits. The large wire with the 50 amp fuse you had an issue with, would have only caused an issue with the circuits powered by that supply. The instrument cluster is powered from the BCM 2 circuit, thus the reason why it worked.Side question: if my BCM did not have power, how was my cluster displaying my mileage?
Test for voltage at:Regardless, I went to the rear of the car and reconnected everything. I used my multimeter to test for 12v on pin 56 of the ECM connector. I was surprised to see now, there is a minor NEGATIVE current draw on that pin, and on pins 3, 5, and 6. I'm talking like, in the range of 10-20 millivolts.
So I defer to people that understand electricity better than myself. What does this mean?
Not to be a smart ass, but that probably means you have your meter leads hooked up backwards. Doing current checks isn't really that useful. At least in this case. I think you're still trying to figure out if things are getting voltage or not.So I defer to people that understand electricity better than myself. What does this mean?
Outside contact of fuse 25 in BCM: +12vTake a look at my diagram in post 507. You will see that the BCM is actually divided up internally into 4 major circuits. The large wire with the 50 amp fuse you had an issue with, would have only caused an issue with the circuits powered by that supply. The instrument cluster is powered from the BCM 2 circuit, thus the reason why it worked.
Test for voltage at:
- Both sides of fuse 25 (10A ECM/TCM) at the BCM - You should have 12v all the time
- Both sides of the 20A "PCM/ECM" at the fuse box - You should have 12 with the ignition on (I PREVIOUSLY SAID THIS SHOULD BE 12V ALL THE TIME - I MISSPOKE AND EDITED MY PREVIOUS POST)
At this point, I could be doing anything wrong, I realize that. But, I just re-tested, ensuring that I am not reversing the probes on my meter.Not to be a smart ass, but that probably means you have your meter leads hooked up backwards. Doing current checks isn't really that useful. At least in this case. I think you're still trying to figure out if things are getting voltage or not.
Looks like that fuse is blown. You should measure the same on both sides of a fuse (with respect to ground).Outside contact of fuse 25 in BCM: +12v
Inside contact of fuse 25 in BCM: 10-20 millivolts
So fuse 25 at the BCM is blown. Replace it and that should be enough to get the PCM communicating with the rest of the car.Outside contact of fuse 25 in BCM: +12v
Inside contact of fuse 25 in BCM: 10-20 millivolts
Please note: This issue will likely be resolved by fixing the fuse above!Both contacts of 20A "PCM/ECM" fuse: no voltage
I tested with the fuse pulled. With the fuse in, both sides show +12v.Looks like that fuse is blown. You should measure the same on both sides of a fuse (with respect to ground).
Working on testing this now.Please note: This issue will likely be resolved by fixing the fuse above!
Lack of power at the 20 A PCM/ECM fuse, this is either an issue with the powertrain relay, or more likely the relay is not being triggered by the BCM. There should be a yellow wire running from X2, 58 at the PCM to X5, E2 of the fuse box. This wire applies a ground to the PWR/TRN relay, in turn supplying power to the 3 wires at the PCM. You should see this wire have about 12v until the ignition is turned on. Check both ends of the wire if necessary.
Waste of time - if the PCM never powers up, it can never command the PWR/TRN relay to turn on. You need to resolve the other issue (lack of constant power at PCM X2 56) first. As I said above, there likely is no issue with the lack of power at pins 3/5/6.Working on testing this now.
If the fuse is good, check for power, in order, at:I tested with the fuse pulled. With the fuse in, both sides show +12v.