SOLVED! No Crank / No Start

[Scry0402]

Hi All,

I'm new to the forum and excited to be posting in hopes you might be able to help me out.

I bought a 2003 Trailblazer with a known No Crank / No Start problem. I took a chance on it in hopes I could find the issue and use the vehicle as a daily driver.

In an attempt to keep this post relatively short, I'll just cut to the chase.

The guy I bought it from tried doing all the basic things. He put in a new ignition switch, he put in a new starter, new starter relay.

Just to verify all was well there, I went back and double-checked his work. I tested for voltage on the Yellow (when key is in start position), White, Pink, Brown, and Orange. Yellow had voltage only when key was in Start, all others were hot when key was in "on." Also have voltage on all the same wires at the big C201 connector right under steering column.

I've gone up to Fuse Block under the hood, checked all fuses, no bad fuses. Crank fuse gets signal when key is in start position, all other fuses have necessary voltages when key is in on position.

I removed starter relay and did the jump test.
With key "on" I have voltage at sockets #86 & #87.
I can jump 12v from socket #87 to socket #30 and vehicle will turn over and start.
Socket #85 is not getting the ground signal from the PCM.

I have plugged a scan tool (a cheap bosch brand that someone borrowed me) and when following instructions on it's screen it seemed like it was able to communicate with PCM as it asked me to confirm the vehicle was a 4.2L Trailblazer.

So it seems the PCM is communicating. I've gone as far to check individual sockets on the PCM connectors that should be receiving power from iginition and battery, all had power as well. No bent pins on PCM as I inspected all of that by removing each connector to just verify good connection.

When moving key into on position I can hear fuel pump engage.

I've got headlights, dashlights, instrument cluster backlight, and radio and the lights that you see on in the dash in the picture attached.

When moving the key to start position, all lights on dash, and in instrument cluster go out.

I DO NOT have any other lights that illuminate on the dash other than what you see in the attached picture below. I also do not have any Blower Fan or any illumination on the HVAC display that would indicate air temperature, fan speed setting, etc...

Two days ago I was troubleshooting this and the key must've accidentally been left on as when I went out to close the garage up for the night, I saw the tail lights were illuminated, the back license plate light was illuminated, and also the dash magically had all the dash lights on that you'd expect from with the key in the on position but motor not running.

I hit the key, it started, drove it around the block a couple of times parked it. Left it sit overnight. Next morning, back to square one.

So I'm left scratching my head as I don't know what happened to have all of the lights on the instrument magically light up a couple of days ago to let me start the vehicle using the key.

Based on what I've read on previous threads on this site, it seems like the PCM sends the ground signal to socket #85 so long as the BCM gives it the green light to do so. I'm thinking the problem resides somewhere within that.

Sorry for the long post, hoping be thorough yet brief. Any help from any of you would be greatly appreciated.

Thanks,

Ryan

Below is what is on the dash with key in the "on/run" position.

 

[mrrsm]

Welcome to GMT Nation, Ryan...

Even with the proper Color Ignition Wires Checking Out for Voltage and Probe Light responses... if the "Rack Teeth" inside of the New Ignition Switch were misaligned prior to its installation and are Off by even a Single Tooth... that misalignment can cause the problem you are experiencing. It is Best to use ONLY the ACDelco Brand Ignition Switch for the Choice Replacement Part.

"He put in an Ignition Switch..." Which invites the possibility that this problem is Mechanical...***

If you decide to overcome a possible Bad Switch Installation *** done by the Previous Owner... Prior to doing so, please Install the Ignition Key and then Rotate the Key through the Start/Run Position all the way Counter-Clockwise as far as it will move prior to removing the Key from the Switch.

Then after pulling out that Switch, compare its appearance to the New ACDelco one for Matching Teeth Alignment. If you can see any differences... then you may have nailed down the cause of this No Crank-No Start problem. Please be Aware that unless you buy the ACDelco Ignition Switch directly from either NAPA or a GM Dealership, then you run the risk of obtaining a 'Bogus Part'.

Your Diagnostic Approach is proof that you've been Thoughtful, Methodical and Skilled. You don't mention viewing the FAQ on the Main Page of the Trailblazer Sub-Forum, but it looks like you've already read through it and used that information as well. Technically, since you were able to Jump Start the Engine and get it to Run... it seems that you followed the recommendations laid down by @MAY03LT in this Video:

...and this is another one from Eric "O" at South Main Auto covering the Light Probe Method to investigate the Ignition Switch Wiring as echoed with your own Diagnostic Actions:

 

[Scry0402]

Hi MRRSM,

Thank you for the quick response.

First, thanks for the sharing those two videos, I've watched them multiple times just to see if I missed anything. Based on probing and voltages, unlike Eric "O" in the above video found the pink wire not receiving the correct voltage and then losing it in the "crank/start" key position, I do have all the voltage necessary through the key cycle.

The brand of ignition switch the previous owner of the vehicle recently installed is a "Standard". I don't know if he took the time to align it correctly prior to installing it.

Do the AC Delco Ignition switches come pre-aligned to the correct location?

What's got me just so intrigued about this issue is why only the "PRND123, Service Engine Soon, Battery" light come on when the key is rotated to the on position. This could occur even when the ignition switch is misaligned despite the key being able to cycle through Lock/Run/Crank?

I thought that maybe since those lights on the dash don't appear to illuminate when key is turned to on, I could rule out a switch issue.

I will track down a switch today and compare.

Thanks,

Ryan

 

[mrrsm]

At this point... "All Roads Lead to Rome..." as being a Suspect Ignition Switch. The thing to remember is that if those "Teeth" ARE Misaligned, they not only remain Out of Position and able to cause the internal Brass Contacts to mis-connect when the Key is in "Start/Run"...but they can also remain in a wrong position allowing 12 Volts DC to keep flowing even when the Key is Off.

So eliminating this possibility can only be investigated while the Switch is R&Rd and exchanged with the OEM flavor of ACDelco. And...No.... Even with ACDelco Ignition Switches, there is always the chance of having either the Original Customer or the Counter-Person "fiddling" around with the Teeth Settings before and after a Return-Re-Stock of this item by their having easily rotating them out of position.

This next video WILL make your Skin Crawl as 'Ichabod Crane' with his "Nails on a Black Board Voice" describing this R&R with the additional Noise distractions of his Voice, a Fighter Plane, Pixar's "For The Birds" and Raging Fire Truck Siren all blaring away in the Back Ground.

Just turn down the sound and *Freeze Frame* the Images on Screen long enough to make-save some Screen Print JPGs at the points where he is showing what the Teeth Alignments look like inside of the Ignition Switches he is comparing. Then just try to emulate that position on your own New ACDelco version if yours does NOT look exactly like the ones he is showing on this video:

 

[budwich]

when your key is turned to "on", as the first time / check, the system goes thru a "all lights / bulb / indicator" check and ALL should come on. IF you are not seeing that, it is likely that either the switch is bad or you have connection issues there in and around.

 

[Mooseman]

I'm also suspect of the ignition switch, either defective or not installed properly.

And just a word on the brand. ACDelco updated their ignition switch to address the obvious early failures and added special metal contacts to them. Other brands likely did not. So far, all other brands used by people here have failed early although did work initially.

 

[Scry0402]

Thanks again.

I will watch. I plan on replacing the ignition switch with an AC Delco switch regardless of whatever this issue may be. Prior to leaving to go get the switch I thought I would try and run my diagnostic tool again on the car to see what codes I get. This time I got a whole bunch of codes from the ECM and the OBDII. I'll list them, maybe you can give me further insight as to what they are telling me?

ECM Codes:
P0621-Gen Lamp L Control Circuit
P0713-Transmission Fluid Temperature Sensor A Circuit High Input
P1120-Throttle Position (TP) Sensor 1 Circuit Performance
P1220-Throttle Position Sensor 2 Circuit
P1271-Accelaration Pedal Position Sensor 1 To 2 Correlation
P1635-5 Voltage Reference 1 Circuit
P1639-5 Voltage Reference 2 Circuit
P1682-Ignition 1 Switch Circuit 2
P1633-Ignition 0 Switch Circuit

OBDII/MOD Codes:
P1120-Throttle Position Sensor 1 Circuit Performance
P1220-Throttle Position Sensor 2 Circuit
P1271-Acceleration Pedal Position Sensor 1 To 2 Correlation
P1635-5 Voltage Reference 1 Circuit
P1639-5 Voltage Reference 2 Circuit

There are also 3 ABS codes that I wont list since those don't appear to be inhibiting the ability to start the vehicle.

Thanks,

Ryan

 

[Mooseman]

Yep, ignition switch still the prime suspect. That or a main power feed is broken.

 

[Scry0402]

Here's a picture of the ignition switch the guy put in (Standard) and the new untouched ignition switch I got from a GM Dealer. Old Switch is on the left, new AC Delco switch is on the right. I have not touched either.

I turned key back as far as I could with old ignition switch in and pulled it out and then set it side-by-side to the new one. They look like they match pretty close.

 

[mrrsm]

Two Part Suggestions:

(1) Okay... without completely re-installing the Plastic Steering Column Pieces afterwards... try installing the ACDelco Switch as it looks right now and make certain the Shifter Handle is in Park and slip in the Key for a "First Try"... If the Motor does Not Fire Up... Remove the Switch and rotate the Teeth ONE NOTCH and 'Wash, Rinse ...Repeat'.

(2) Since your SUV came from an Owner who let the vehicle sit dormant for some length of time...and with the revelation of seeing all of those Codes... Mask and Glove Up to avoid inhaling Dried, Desiccated Dust from Mouse and Rat Crap laden with Hanta Virus in their dried Feces and Urine...(Different Virus...But JUST as Dangerous as COVID if not more so with a High Fatality rate if inhaled or in contact with the Eyes...) Then... Raise the Hood to search all over the Engine Compartment for any signs of Rodent Droppings, Nests and most importantly...CHEWED WIRING HARNESSES AND CONNECTORS. These are the artifacts of the Problem you might see under there as captured by another GMTN Member up in Rhode Island:

 

[Scry0402]

Thanks again for all the help. I really do appreciate it.

No luck. Tried when matching it to previous switch. Also tried matching this up to the 'Ichabond Video' still no luck.

So the orientation of the switch in the picture I provided above was with the key turned ALL THE WAY BACK (towards you) and since I couldn't remove the key in that position I took the switch out with the key left in the cylinder.

I tried putting new switch in leaving the key cylinder alone in that position while match the gears on from the old ignition switch.

In the 'Ichabond Video' he looked performed this with the key cylinder in the lock position and the key removed.

So that's what I did, moved the key cylinder into the lock position and removed the key. Tried aligning the AC Delco switch according to the Ichabond Video, put it in, no luck.

The key cylinder in this vehicle is also aftermarket. I am unsure if the previous owner replaced that himself or not.

A little back history, I bought the vehicle about a week ago. The vehicle did run and drive the owner told me as recently as St. Patrick's Day. As I stated, the vehicle magically fired up for me too on Friday Apr. 4th.

Since he put these new parts in it (starter, relay, ignition switch) and none of this fixed the issue for him, he decided he wanted to get rid of it.

Thanks,

Ryan

 

[mrrsm]

If the Battery Voltage has dropped below Nominal Levels... the removal of the Ignition Key or the movement of the Shifter handle may not be possible.

Here is a TSB or GM SI PDF that covers a raft of problems including many of the Codes you mentioned in Post #7 narrowing the issue down to "Chafed Wiring" caused by Exposed Metal Retention Rings encircling the Three PCM Wire Bundles leading to multiple Shorts to Ground in the PCM Harness.

The PCM itself may become damaged with these Multiple Shorts to Ground events and if necessary... eBay has quite a few Used PCMs available for not too much money. Of course sorting out any-all Shorts in the Three Harness Bundles should be explored first prior to attempting the installation of the PCM:

 

[Scry0402]

Thanks.

We will have to go through and inspect wiring harness as best as possible.

I will re-install the ignition switch in the same manner as what the old one came out.

I will inspect wiring harnesses under the hood.

In the essence of transparency, I'm a little concerned because it appears as someone has been in messing with the wires in/around the column before. It looks like something aftermarket might have been installed and then disconnected? I'm not sure, but as you can see the by the pictures below, there's several wires that were butt spliced back together.

There's also a connector with tape over its ends that comes off the factory harness that appears to be unused. I just happened to be further investigating after removing the hush panel and found these items.

Thanks,

Ryan

 

[mrrsm]

No pics in view so far... but yes... After-Market Wiring = "The Mystery Meat" of No Start issues. Something like this 'Thing' could become your Best Friend in locating and Isolating "Automotive Open Circuits-Broken Wires".

However... Amazon may have a Long Delay in making deliveries of non-essential electronic equipment while shipping other more critical items to us all during the COVID-19 Crisis:

Robot Check

 

[Scry0402]

There's also this plug under the hood. Assuming it's for a block heater. We live in Minnesota.

Let me know if pics from previous post don't get posted and I will re-try. Here's a picture of that plug under the hood.

 

[mrrsm]

*OUCH....!* Yes... Wow... What a 'Bag of Snakes'. You might ask the Prior Owner what the Brand-Make-Model-Device was that he attempted to have installed down there so you can obtain their factory Wiring and Installation Diagrams and Instructions to allow you to de-engineer it all. At First Blush... I suspect you'll eventually find the problem once you unwrap all of the Skin-Tight Electrician's Tape under the Steerng Column and begin probing everything.

Speaking of Wiring Diagrams (You can thank @Mooseman) for locating that Probe AND for setting up the GMTN Member On Line Library of GM OEM Factory Service Manuals... including one for your particular vehicle available via this Link:

Need service manuals? Get them here!

This is great!!! Thanks, I'm dl'ing right now.:thumbsup::thumbsup::thumbsup:

gmtnation.com

 

[Scry0402]

Do you know what that big connector is that has tape over it?

It comes off the factory harness coming in through the firewall.

I'm not sure if it was the previous owner that attempted installing anything or not.

It looks gross, but every wire that was cut was sliced back to its original wire based on what I can see.

My assumption is my problem lies somewhere within that.

Thanks,

Ryan

 

[TJBaker57]

The pictures with the 2 blue and one black connector...TCCM. the wide gray connector with the black electrical tape is I believe a splice pack = normal

Edit; a splice pack is a data wiring junction point

Also seen are several blunt cut wires. Also normal I believe though they are normally better secured. Trailer brake controller wires, for aftermarket installation of electronic trailer brake controls

 

[Scry0402]

With regards to the codes I listed, just talked with a mechanic buddy of mine. He said all the codes I listed were probably because I disconnected the PCM connectors yesterday with the battery still hooked up.

I did this to check to make sure we were getting battery signal, crank signal, ignition voltage where it's needed on the inside of each one of the connectors to the PCM.

He said those codes are likely a result of that and instructed me that I can clear them.

Thanks,

Ryan

 

[mrrsm]

First Things First... as per my edit to Post #16, I've included the info on how you can get a Free GM OEM Factory Service Manual specific for your SUV and examine the GM Ignition System Harness Diagrams to find out what they are SUPPOSED to look like. Then you can compare those Wires, Colors and Wire Circuit Numbers against the source wiring that has been CUT and SPLICED in order trace out each one from their Points of Origin to their Proper Destinations.

You might get lucky Right Off The Bat and listen for the Broken Wire Probe to start screaming as soon as you turn the Ignition Key to "Start/Run" and Wave the Wand around that Ugly Bundle. If it Squawks.... Tear the Tape off of the Harness and then narrow things down to JUST the ones that are Broken, Separated... or just plain Badly Put Together with Butt Connectors that should NEVER be used in any Automotive application.

This Video will serve to show you How this Equipment Gets Properly and Easily Used to Trace Broken Wires HIDDEN UNDER THE TAPE... and How to Properly Repair Any and All of those Broken Wires using Solder and Heat Shrink Insulation:

This is Part 2 of a Two Part issue with the same problem you are facing. Please note that you do NOT need such an expensive version what the VOP is using here to sort things out...this just shows you what is possible to accomplish with this rig:

 

[TJBaker57]

Here are a couple of images from my 2002 TrailBlazer. You will note some of the same in your vehicle.

 

[mrrsm]

Just to be on the Safe Side... Before you begin moving things around to access and examine that bundle... you might want to Probe the Orange Wire shown on your Finger Tip in the highlighted image below to determine if it is "HOT AT ALL TIMES" vs. "HOT IN RUN" as generally...the Thicker Orange Wires normally carry 12Volts DC (+) and if you nudge it into anything that Grounds or Shorts under there... things could get 'Exciting' pretty quick.

I'd also suggest that you put some Wire "Acorn" Nuts over all three exposed Cut Wires in that image just as a precaution. The Blue-Black Colored Module just below your hand looks like it might be the TCCM (Transfer Case Control Module):

 

[Scry0402]

Thanks for the replies @MRRSM . It looks as if @TJBaker57 has a similar open ended orange wire under his dash as well. Glad to know much of that is factory.

I will still probe that orange wire and verify what is going on there. I'd suspect 12v though as indicated on the tag around the harness @TJBaker57 shared.

Does anyone know specifically what information the PCM needs in order to ground the Black/Yellow wire on Pin #48 of the C1 connector on the PCM?

I'm still just blown away that I get absolutely no other lights on the dash other than SES, Bat, and PRNDL when the key is turned to the "run" position.

The only other small items I can think of that I haven't mentioned yet are:

When key is in ignition with door open, we do get the beeping noise to indicate key is in ignition.
If driver seat is all the way back, the seat engages and comes forward when the key is put into the "run" position.
I've also heard noise out of the mirrors when the key is in this position. Most noticable from the right mirror where it turns the mirror all the in and clicks 2-3 times before giving up.

I've got headlights, taillights, dome lights, radio, rear wiper, front wiper, back lighting to instrument cluster.

No gauges on instrument cluster work. At minimum I'd expect to see the volt needle move and the fuel needle move if gauges were getting supplied power.

I keep looking at schematics but it's hard to piece together exactly where all those "startup" lights get powered from, and what is needed to power them. I'm talking the Check Engine, oil, ABS, Traction, Airbag, etc....that all come in when you turn the key to run.

I hate to stay fixated on that, but the one time the vehicle did start on its own in my possession, all the lights on the dash were illuminated.

Maybe that's nothing, but I tend to think it's a pretty large clue as to what is going on here.

Thanks again for all of the help today.

Ryan

 

[Mooseman]

That connector you're holding that's taped up is the main CANBUS splice pack. it's used to do diagnostic work on the network. If you pull out the "comb" in it, it disconnects all the modules from each other. It should be left alone.

The other blunt cut wires are for hooking up a trailer brake controller and came like that from the factory. They too can be left alone.

I've disconnected the PCM countless times with the battery still connected (I know, that's bad to do) and I never got any codes. In fact, doing that will clear codes. Try clearing all the codes and see if they come back.

However, the other splices/butt connectors look like a remote starter was installed at one time. Could very well be the source of your troubles. You should recheck what you're getting for power at the ignition switch in RUN and START like in the video by Eric O. The switch may still be off a tooth.

Another question. Is the Security Light on or flashing? It's OK if it comes on for a second when you first turn to RUN during the bulb check but it should go out and stay out after that.

 

[Mooseman]

Does anyone know specifically what information the PCM needs in order to ground the Black/Yellow wire on Pin #48 of the C1 connector on the PCM?

IIRC, it needs the 12v+ trigger from the ignition switch AND the go ahead from the BCM for the anti-theft. The PCM also needs to be powered on and there are several feeds for that. (I have to ask) You did check all the fuses?

 

[Scry0402]

@Mooseman , thanks for the reply.

Yes, I checked all fuses at the under hood fuse block. All fuses checked out fine.

I also checked the ignition fuse at the rear fuse block and that is fine too.

I'm only getting the SES, Battery, & PRNDL lights on the dash when key is turned to run. No other bulbs present.

Assuming that I hook a code scanner up to the DLC, and it's able to speak to vehicle, it's fair to conclude that with the key in the run position, the PCM is powered up since it's talking to the code reader.

I apologize if I seem naive, but what is the IIRC you referred to?

Thanks,

Ryan

 

[Mooseman]

I apologize if I seem naive, but what is the IIRC you referred to?

If I Remember Correctly.

So no gauges, DIC or odometer? I would still suspect power feed from the ignition switch or something related to it. Try to communicate with the PCM in both RUN and START.

 

[Scry0402]

So codes are gone, no codes coming from ECM or anywhere else other than ABS for what looks to be a bad wheel hub.

@Mooseman all wires on ignition switch are hot with with the key in "run" with the exception of the yellow which only gets on in the crank position. Voltage on pink wire does not go away when key is turned to crank position.

 

[Mooseman]

I guess you'll need to check if the PCM is getting that signal from the switch.

 

[mrrsm]

Speaking of the Security Issue... If the Top Cowling on the Steering Column is removed... If you can reach both of these at the same time... If this item is present ...try Jiggling the Small Electrical Plug just over the Key-Lock Tumbler while Turning the Ignition Key simultaneously and see if maybe that connection is loose.

If the Motor Starts and Runs... then the Temp "Fix" for this problem could come from wedging a Cut Off Small Zip-Tie adjacent to the Connector-to-Plug interface to maintain the connection and then use either some Duct Tape or another Zip-Tie to secure that wedge in place.

When the Key is in Start/Run... the 12 Volts DC Power available on the Pink Wire also provides constant power to All Solenoids inside the 4L60E Transmission.

 

[Scry0402]

@Mooseman
Yesterday with my test light I checked for voltage on several sockets of each PCM connector. I'll give you a list of what I did check:

Connector C1
Pin 19 (Ignition 1 Voltage) -Good
Pin 20 (B+ Voltage) - Good
Pin 21 (Ignition 0 Voltage)- Good
Pin 29 (PNP Switch) - Good
Pin 31 (Crank Voltage) - Good
I also took a hot wire and put it in pin 48 (the ground signal wire) just to see if one the fuse block I would get 12v with a second test wire. I did. So I know that wire is good.
I did not check Pin 32 (VSS Signal), 58 & 59 both Class 2 Serial Data. Don't think that would work with a test light anyway cause isn't that transmitting information, not voltage?

Connector C2
Nothing on that one but ground (#65).

Connector C3
Pin 17 (Ignition 1 Voltage) -Good

And that's it. Maybe you have other pin locations on connectors I could try?

@MRRSM I did the jiggle test of that plug while turning key. Nothing but the SES, Battery, and PRNDL lit. Still No Crank.

Thanks,

Ryan

 

[Scry0402]

The wires under the dash that have some sort of splice in them and what they correspond to on connector C201 are as follows:

A16 - Black Wire - Ground
E2 - Tan Wire - Ground
E6 - Light Green - Key In Ignition Signal
E7 - Remote Shift Selector Signal

If I take a jumper wire from battery + and connect it to a test probe, my interpretation is I should be able to test grounds by probing them with the test light, and if the test light comes on, the circuit is closed, and if the test light does not come on, the circuit is open?

Correct?

Thanks,

Ryan

 

[budwich]

If you back up a bit... in the distant previous posts, you indicated that you could jump a wire to cause the starter to turn and thus start the truck. Is this no longer the case?

further, at the ignition switch, you need to see what state ign 0, ign 1 and accessory are in the various key positions (ie. off, run, start). post a table with the results, and hopefully you can get to the bottom of this.

 

[Scry0402]

@budwich

Yes, the car can still be jumped for socket #87 to #30 on the fuse block and the vehicle does start.

I just performed this a minute ago.

 

[mrrsm]

Have you found any "Sketchy" Wiring or Add-Ons connected to or around the either the BCM or the Fuse Block under the Driver's Side Rear Seat? Any Fuses blown back there?

 

[budwich]

@budwich

Yes, the car can still be jumped for socket #87 to #30 on the fuse block and the vehicle does start.

I just performed this a minute ago.

ok ... good, with the amount of "touching" that you did, I just wanted to make sure you had some "base level operation". IF you can, I would do the check that I suggested and post a table of the results. then people can look and see what's happening thru the ignition switch and maybe spot something.

One other thing... related to your lack of "check all lights", do you ever see your DIC light? of course, that's if there is one.

 

[TJBaker57]

OK,,, I'm just pulling this out of my,,,, whatever....since the BCM is required for security system OK before starting....and the truck did start for you that one time....maybe some loose/flaky wiring at or to the BCM?? Check for proper power and ground there?

Again,, this is just a thought, and admittedly not a fully vetted one at that.

 

[Scry0402]

@budwich

Nope, no DIC light. Only the SES, Battery, PRNDL is on.

Attached is a table of what wires are hot with the key in the Off/Run/Crank positions.

@MRRSM -nothing sketchy back by the rear fuse box. I haven't gone through and tested all the rear fuses but the ignition fuse located back there does have power.

Thanks,

Ryan

 

[Scry0402]

@TJBaker57 & @MRRSM

Attached are some pictures of the rear fuse box. I know it's hard to tell just in a couple pictures, but doesn't look like anything is out of place.

Thoughts on things to check back here potentially?

 

[TJBaker57]

You have mentioned a diagnostic tool. What is it? Can it address the BCM? If yes then that could at least confirm the BCM is powered and awake.