VZ Exec No Start, No fuel pump, Fuel gauge error.

[Fu Manchu]

This has me stuffed.

Father inlaw's VZ has been sitting since March.
New battery installed last Jan.

I brought it over for a clean and oil change.

It didn't kick over first go at his, but second go and away it went (just)
260,000 k's and it is sweet as a nut. Smoothest (and internally clean from what I can see) VZ I've ever driven.

Had battery disconnected for a week because it was flat and I didn't want it flatter between me having time for it. (needs recharging) It's on charge at the moment.

So no start, nothing. Ok, I'll put my battery in.

No start.
Nothing. No fuel pump priming. No starter click.

Checked every fuse. All good.
Swapped relays with high beam relay. No change.

Then I get low fuel. Fuel gauge error.
It is a near full tank.


I'm off to plug it in and see what codes there are.

I have a spare wagon computer set I might swap as well to see if that changes.

Anyway, any ideas?

 

[Fu Manchu]

Video: https://imgur.com/a/XHiNFhv
Enable sound buy clicking the speaker icon in the video.
Went through the gears also.

 

[Fu Manchu]

No codes logged. Communications with the car fine.

... swap computers, here we come.

 

[Fu Manchu]

Similar threads
https://forums.justcommodores.com.au/threads/vz-v6-no-ignition-or-fuel-pump.224106/

https://forums.justcommodores.com.au/threads/fuel-gage-error-displayed-ute-wont-start.99390/

https://forums.justcommodores.com.au/threads/vz-wont-start-possible-bcm-issue.282378/

 

[Fu Manchu]

All fuses check out.
All relays seem to be functional. (have been able to swap across from my car)

Swapped the computers to known functional ones.
It's from a wagon, which worked well in the crewman (other than fuel accuracy).

Car cranked. No dash issues.
However couldn't hear the fuel pump.
No fan in the car.

So that might come down to the computer being from a wagon?
Don't see how the ECU would differ though.

Anyway, looks like a trip to the mechanic.

Going to lay money on faulty ECU.

 

[rambunctious]

Remote battery low and not cancelling the security system.
Do you have another key remote to try ??

 

[Fu Manchu]

I thought that, but it opens the doors and if I press the button, the lock light goes out.

Either way, it served it’s purpose. A huge change by swapping the computers.

Something else occurred to me. During production there was a change in how the cars system communicated. This VZ is an ‘04.
The computer set worked from a late VZ ‘06/07 wagon.

Remember the thread of the forum member that dropped a 6 speed auto into a Crewman? He mentioned there was a change during production of the VZ. So maybe it’s that. His Crewman was pre the change (maybe 5.7ltr, not 6ltr) and can only assume that also varied across the V6.
Computer set runs my crewman fine.

 

[Fu Manchu]

Anyway.
The fix.


RAC guy jumped the starter relay.

So weird as.
I pulled all the relays from my VZ and my battery put them in and nothing changed.

This guy jumps the starter relay and replaced the same relay back in and no dramas.

Gremlins

 

[Fu Manchu]

And there is some discussion about which pins to jump, so this is the ones he used for those wondering

 

[Fu Manchu]

... and it won't start again
So no fix

Was driving great.

Next will try this path of investigation
https://forums.justcommodores.com.a...l-start-if-i-bypass-the-starter-relay.157340/