2006 brm won't run

Hey all, so I started my 06 after she's been sitting for awhile, fired up, ran no problem, gave it some throttle, and the glow plug light flashed and she shut off.

Since then, I've tried to connect to the obd and it can't communicate with the obd. The glow plug light will not illuminate when key on, and it will not fire.

If I leave it for a decent time, it will fire back up and then die again shortly after.

Any ideas or suggestions?

Cheers all

Possible relay 109, it supplies power to the ECU.
[Once again I was mistaken, thanks OH, but there is a relay that feeds power to the ECU]

I've tried to search for this relay... Where is it on the car?

It isn't. That is on older cars.

What you need to do is try and isolate which modules are not powering up, and which ones are not communicating.

The BRM's ECU has a relay UNDER the underhood fuse box. The glow control unit is under there as well. I have never seen one fail. I have, however, seen neglected underhood fusebox covers get dirt and moisture inside, and ruin that panel.

You can fairly easily unscrew the fuse "plate" after removing the leads to the links on the front side, and lift the plate up and out and look underneath for corrosion. Disconnect the battery first!

All of the car's electrics go through that underhood fuse box.

What's weird is that it was communicating with the obd at one point. Now it's not. It also will randomly show the glow plug light when I key on as well. So seeing its absolutely freezing outside. Do you mind sharing what order you would suggest to check all of this? Also iirc you can get access to that glow plug relay by removing the battery and you can get to it from the side under there.

I would use a suitable scan too (generic OB2 ones won't do) and ask the CAN Gateway, etc. if they have a DTC for no communication with the Engine. That will at least narrow your problem down.

Then examine the underhood fuse box as I already suggested. As well as the grounds, specifically starting with the battery and the ones near the driver's side headlamp.

I have a Ross tech cable, so I'll fire that up and see if it will get anything, bare with me

So it says the engine can not be reached. Same with a bunch of malfunctions. Abs, auto hvac, cent electric. Instruments, can gateway, steering assist, radio, aux heat.

I'd expect alot of this since it hasn't been run since the battery was dead prior to starting today.