I figured that rather than continue to post in a discussion about another car (HERE) that I'd start a new discussion.

The condensed summary is that I have a no-start issue;
I get no clicking - so the starter appears to be getting no voltage when I turn the ignition to start.
I have power at the starter relay, and although I was told that there was a bad ground, I get 12volts when I use my multi-meter and go from the hot on the starter relay to the other three... but I will recheck this.

Recap for those of you who didn't read my posts in the other thread:



So I've picked at this one a bit, and I am a bit stumped.

I have a Tech2, but I am not very confident with it.

I believe that I have confirmed that the ignition switch and clutch saftey work;
With my Tech2 hooked up, under the starter relay control testing shows the following:
There is a 'Crank request signal' - this shows as "NO", with the key to on, but changes to "YES" with the key turned to start.
There is a 'Starter rely command' - this shows as "OFF" with the clutch pedal out, but changes to "ON" when I depress the clutch pedal.

I am fairly confident that the fuse box isn't bad - I had a spare that I swapped in, and it didn't seem to change anything so I put the original one back in.
I am having issues trying to properly go about diagnosing this.
I also am clueless on what I need to jump to get the car started;
I did successfully just get the car push started, so it's in the garage right now (when I came home the other cobalt was there, and i needed to finish some stuff on it).

Can anyone hold my hand in understanding this factory service manual?

Can anyone tell me how the dealership may have hot wired the car?

... and because threads suck without pictures:


Here we are on route to Winnipeg - my son took this picture.


Here is my car at the dealership just before getting home.



And here is a picture from last week, the evening before the CSRT-4 went away - we are now officially a two-Cobalt (as daily drivers) family.


I will post here with what I learn, regaurdless of any replies that I do, or don't get.

Thanks in advance for trying to help

 

I seem to be stumped.

I'd really appreciate it if someone might see this and chime in.

I decided in light of the (terrible) service write up, that I'd look at, or for what seem to be the prevailing no-start with no-code issues - bad grounds.

I went through my wiring looking for anything that might cause an interruption in any circuit - I even went the extra step of fully removing a methanol injection setup that I never actually turned on (it was plumbed and wired, but never connected).
This required changing my lower charge pipe - so in went my Hahn pipes.

I buttoned everything up, then went back to looking at the power distribution block(?)/board;
The starter fuse is good, the ignition fuse is good, and with my Tech 2 hooked up, I can see my clutch pedal switch, and ignition switch is good (it responds to changing the position);
I verified with a tester that I have voltage at the starter relay "hot" position;
Now here is where I get a bit muddy;
I remember having pulled the relay, and placing tiny finishing nails into the three other spots - effectively removing the relay from the equation;
I had my wife come out, sit in the car and try to crank the car;
I was able to get the starter solenoid to click - I did this several times, and my wife could even hear it.
I figured that if I was hearing a "click" for the starter, that it must be a bad starter... so I reinstalled the relay and ordered a new Delco starter..

I was kicking myself because my first thought was that it was a bad starter;
Remember that dealership visit(?) - they said starter was good.

I received my brand new Delco starter just before the weekend, and swapped it last night.

Nothing.

I would normally refer to a service manual, but these manuals have been more useless than useful - they are just vague enough that they are seldom referred to.

So I am back virtually to where I started;
I am wondering if I have a bad power block, a bad ECM, or a bad ground,

1) I don't know how to verify if the power block is the culprit.

2) I have both a Tech 2, as well as HP Tuners.
I cannot for the life of me figure out how to change the vin with my Tech 2 on a spare ECM;
I found a video that shows how to do it with VCM editor, but I don't appear to have the change vin option in my VCM editor(?);
It appears as though I have no way to try another ECM to eliminate mine as the culprit.

3) I guess I could look at removing my power distribution block again, and accessing the common ground on the top of the bellhousing to look for any evidence of a poor ground...

But I am feeling rather defeated at the moment.

Can anyone hlep?

 

Not sure if this would help too much, but some googling of key words led me to a couple of items of interest:
https://tech2wiki.com/content/techni...place_ecu.html
https://www.hptuners.com/help/VCM-Ed...change_vin.htm

You may be able to pull out more data of what's happening with Tech2Win application - it seems like there's a license for it from what I can tell updating the BCM and such from various forums.
Also I think they were bullshitting you on the hotwire thing. You can do a jumper bypass as long as the original key is in place (not quite sure with cobalts, but you could do this with old caveliers) like starting a car from a dead battery, but that's all I know of.

As for grounds, you can simply attach a wire to the module and ground it to a clean part of the car to eliminate that aspect.

Sorry I can't really provide any more data.

 

THANK YOU for the reply.

I have downloaded the Tech 2 user guide, and will look it over.

With the second url, I don't appear to have a "Change vin wizard";
I am wondering if my install is old enough that it wasn't included...
Which makes me apprehensive about trying to update VCM Editor - I really don't want to have to buy a new computer to update for HPT.

With the first url, it references getting a security code from Holden(GM) - what's the deal there?
Is there a way around this?
(this was one of the things that I figured would justify the tool's purchase)

I will google "jumper bypass" to see if I can get any headway from there.

 

You can update the software fine, it'll work with your device (unless you're running Windows XP for some reason, it'll work fine on Win 7, 10, and 11).
The security code is reference several times with GM forums in general, this was the closet I code find that kind of described the process, the rest were "I have a buddy". My guess it's that subscription for GM's tools that provides you the key to unlock using the SRS.

As for the bypass, the one I remember on a junker (cavelier) was inside the console, but this was a secondary option:

 

so I finally got it done.

Thankfully, I always have more than two running vehicles, so if one's down for the count, I can enlist another into duty;
I picked on this as I could spare the time, and took breaks when it pissed me off.

I started by disreguarding the waste-of-money (non)diagnosis from the Davis dealership in Medicine Hat - and any time I decided to go back on that decision, it only bit me in the butt (meaning i wasted my time).
My initial thought was to comb over everything looking for a bad ground, and while I was at it, replace the NFG (aftermarket) oil pressure sender, remove the meth injection setup that I never actually used, and finally install the hot side Hahn charge pipes that have been sitting around for nearly a decade,

Before getting the car push started(!) to get it in the garage (the black car was in there when we got home from our trip), I decided on a whim to install the spare power distribution block that I had... and it did nothing.
That was the first time I wasted energy listening the the Davis crap-diagnosis.

I then set myself to scouring over all the looms, breakers, and fuses that might be the culprit - while tagging on the maintenance I wanted to do.

I got everything done, put it back together... and was no better off (that was at around October 10th when I posted).

I then again decided to maybe humor the Davis paperwork...
So I looked into swapping ECM's...
But that was a brick wall - and I decided I would earmark how to change the vins on these spare ECM's at a later time.

I then got to looking more into the possibility of a bad ground - that I possibly missed - because it looked ok... or I didn't see it.

At that time I tried to figure out how the starter relay works n conjunction with everything;
I reasoned that if the dealership was able to hotwire it that should mean:
1) signal is getting to the power distribution block (PDB).
2) everything inside the car (clutch switch ect) was fine (which I did confirm), so looking in the car was a waste of time.
Ergo, the problem must be between the PDB and the starter.

I verified this by figuring out how to hot wire the car by myself;
Essentially the starter relay grounds via the loom which connects to the PDB, and if that relay cannot ground, then signal is NOT sent to the starter.

Look at this high quality ECM/PDB ground junction (spoiler: all Cobalt's use this)



That little 18(?) - 22(?) gauge wire on the bottom...
That was the culprit the whole time.

Here... Let me bend it out of the way so you can better see how it essentially fell off after being in service for a little over thirteen years:



So after getting that figured out, all I needed to do was button everything back up, then find what I screwed up - fix that, and we're back on the road.
Well, after cutting the end off, cleaning it up, soldering short extensions (in the same gauge as the existing loom wires) into that wire coupler, and reconnecting it the the loom...

Speaking of things I screwed up, somehow I managed to bend the #3 injector pin when I was putting everything together - that would explain why the connector was fighting me so bad to lock!




Hopefully my headache, and what I've shared will help someone else with a no-start cut straight to the chase, and get their car fixed in no time flat.

 

Very great write-up. Thanks for this!! I too suffered with the same thing.

 

yeah that ground is a failure point on these cars for sure. great write up