Immobiliser Issues

[brainy]

Not to sure where to post this, but i thought i would provide information for everyone in case they suffer the same curse as me.

How does the immobiliser work?

When you put your key into the barrel, the chip inside the key gets in range of the copper antenna around the barrel. This sends the signal down to the BIU to confirm that the key is coded to match what the BIU is programmed to. If you put in a key that isn't coded to your car, the immobiliser key light will come on solid straight away and you won't even be able to get the engine to crank.
When you start the car, the car will start and then send a message from the BIU to the information panel cluster as a secondary check to ensure everything is right and good to go.

Things to know:
You can get keys re-coded to your car. If you do have this performed, you need to bring all your keys or else you won't be able to use your other key anymore.
Subaru can pull codes from your car in relation to the BIU, immobiliser and cluster area.
Swapping a BIU and cluster out of your car isn't quite that simple. You need to get Subaru (or someone who can do this?) to re-code the BIU, keys and cluster to your car. For instance, swapping a BIU, key barrel and key that worked together isn't enough to get it to work in your car. The cluster also needs to be swapped or re-programmed. These devices also talk to the ECU in the process but i can't confirm if there is a direct impact. I'm led to believe there isn't.
There are many different part numbers out there and apparently they have their differences for a reason. For instance, my cluster part number is: 85033AG860. According to Subaru, the 850 shouldn't change, the 33 is major revisions, the AG seems standard and the 86 is a minor increment, like a superseded model. If the first lot of numbers are different, then there's a very low chance that this would work, but if it's just the last set of digits after the AG which are different, then there is a more likely chance that it would be compatible but unconfirmed. I'm also yet to find another BIU with the same part number as mine.
MT and AT are completely different. The BIU in an AT car has more chips on the board, assuming it has to do with the auto trans. The cluster for obvious reasons is also different with the gear selection display for AT.
The immobiliser can't be disabled. If you are looking at some after market alarm system with remote start, then you would need to hack a chip out of the key and stick it to the antenna to bypass the immobiliser.

I'm sure there is other information i'm missing, but that's all that i can think of for now.

My issue:

This is intermittent, and seems to be easier to produce when warm.
Put the key in the ignition barrel, all checks are okay. Start the car. 1 second later, the immobiliser key comes on solid and the car stops. You have to take the key out of the ignition to reset the immobiliser circuit.
Rinse and repeat and hope the car starts. If not, let it sit and try later. If out somewhere, leave it or get a tow truck.
The car is back at subaru for the 3rd time.
First time they pulled a bunch of codes that were stored. They cleared the codes, couldn't get it to fault so they said to try again.
Second time they pulled 2 codes. Ran diagnostics and pointed the culprit as the information panel cluster. Said, they can't get it to fault again, so drive it and if it does it again, bring it back to confirm the problem.
Third time, took it back and it had different codes in it. One of the codes points again to the cluster. They kept the car for a couple of days, trying to get it to fault.
They've now successfully got it to fault again so they are going through the diagnostics which will hopefully point me to the culprit so i can replace it.

I'll list the codes later for everyone so they can use them as a reference. I'll also advise what they find.

Currently i'm chasing wreckers for anyone who has a similar or same part number, but it's looking like i might have to take a risk and try and just get one that is from a 2007-2008 GT Spec B manual.
I've also pulled the BIU apart and checked the board and chips for any sort of malfunction but it looks from appearance to be spot on. I haven't pulled the cluster apart yet as i'm waiting on the car to wrap up at subaru.

I'm hoping my information isn't required by any of you, but thought i would post some details as it seems to be quite sketchy on the net with not much to go on.

Brian

[bigBADbenny]

Great info - hope you get it sorted.
Sydney seems to be a hotspot for GT wrecks, perhaps put an order in with mat04 for a MY07-08 GT B 6mt BIU?

[bigBADbenny]

Try removing any LEDs on the dimmer circuits which are controlled by the BIU...
Alternatively, see if the condition occurs when 12v power is removed from the AEM Failsafe which is tapped into the cluster.
Iirc members have had issues with the key lock barrels which have caused issues.

[<GB>]

Did you ever try starting the car with the cluster out?

[brainy]

BIU does control the lights, but they are separate chips. If you fry them, the car will still work and the immobiliser circuit will be unaffected.

My led's get the signal from the biu but the power source is from a relay. BIU upon inspection looks good.
So far, Subaru have told me that all signs are pointing to the cluster, but a new one would be a back order from Japan job with no ETA.
I'm hoping to hear more today.
My last chat with them was indicating a cluster or wiring fault. Perhaps some wires were damaged at some stage, but checking them from the cluster, to the biu, to the ecu look fine. I guess next would require tracing them to the engine loom. Granted it's not a fully comprehensive look, but i may have to get down to that granular level later.

The AEM failsafe was put in after the issues with the immobiliser started (useless device is out .4 on reading at idle).

GB, that test, i think from memory i did try it and the car wouldn't crank at all. But once i get the car back, i'll give it another go to confirm.

Brian

[bigBADbenny]

How about just trying out a working cluster?
Mine will be out to do the rpm tap soon enough...

[<GB>]

How about just trying out a working cluster?
Mine will be out to do the rpm tap soon enough...

if its a coded item it wont work unless the new cluster is coded to that car, that's why I asked if it will start without the cluster. if it starts without the cluster this means its not linked to the biu or immobiliser system, some cars are set up like this some are not.

[bigBADbenny]

Do you have a particularly large bunch of keys on your key ring?

Have you tried just a bare key?

Still have the issue with your spare key?

[<GB>]

Do you have a particularly large bunch of keys on your key ring?

Have you tried just a bare key?

Still have the issue with your spare key?

he's tried all that

[brainy]

I'm waiting on a call back from their diagnostics, but so far they've commented that the wiring seems to be okay. They are testing frequencies etc.

I guess what i wanted to achieve in this post is to supply information for others out there who might end up having the same problem. There's a couple of cases of this being mentioned around the net, but no real information to follow.

I'm waiting on a call back from Subaru to advise what the next step is. So far they've confirmed that there's nothing wrong with my wiring and that none of my extra accessories are a concern.

Brian

[bigBADbenny]

Thats a major bonus that they are not spinning out over you mild mods

Which dealership is it?

[KiDo_Tuning]

Kaeb appears to be parting out his car, could be good for checking

[brainy]

So an update to this issue for future reference for anyone who may have this problem.

1. biu was replaced (unnecessarily), along with 2 new keys and the antenna around the ignition barrel.
2. ecu was swapped out for testing.
3. cluster was swapped out for testing.

Then, we followed the next steps in diagnostics. Fuel and spark.
Issue cuts fuel and spark. Hot wiring the fuel pump proved pointless as spark was cut in the process.
fuel pump relay was changed.
A whole bunch of fuses and relays were replaced.
Other theories consisted of cam sensors, crank angle sensors, coil packs, spark plugs and various other electrical components. All were replaced, including fuel pump and fuel pump controller along the way.

The final thing that was left in relation to testing was to replace the wiring loom. All diagnostics indicated that it was an issue between the biu and ecu. We had set out to just replace the main loom, however, it seems that you need to also do the whole loom as the plugs and wiring positions don't match in the main engine bay plug to what my loom has. There were also some other differences. A quick example, the heater box in my loom had a relay attached to the side of the heater box. In the loom i obtained, it didn't have this and ended up tracing it to the relay locations under the dash with the fuse box. There were subtle changes like this along the way which made it somewhat a challenge but as it turned out we got there in the end.

I can now say that i'm over seeing wires and can probably answer a lot of questions in relation to wiring, where they run and what they do. Sadly, it has to be the last thing to try and really it's not a small job but still achievable. wiring loom replaced and the issue seems to be resolved so far.





So it would seem the issue was caused by a fractured wire somewhere in the million wires in the loom and was causing it to fail. the diagnostic tool was also showing us some B codes which you can't normally see and they were saying there was a malfunction in the canbus communication. I've been back on the road for 11 days now and i'm code free and the car starts every time (thank god!).

Brian

[bigBADbenny]

That looks like it was INTENSE!

[<GB>]

Sounds epic!!!