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Drawnnite

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Yeah am in the process of figuring out which scan tool to get (have a small one but it doesnt do much other than read obd2 codes)
Probably get a smaller one that can do live readings (just to leave in the car) and also grab a tech 2 knock off aswell.

Got some other info/recommendations which will be trialled.
- Inlet Manifold gaskets, could be a small leak
- Exhaust leak (but i'd find it strange if it happened to be the same spot after the extractors/cats were installed)
- Test circuit back to the PCM/BCM (need to scope out a wiring diagram/manual)
- Extension looms to swap left to right along with a scanner to see if live readings follow it or swap.

Is just a slow process with having to constantly get under to check the o2s.

Edit: Found a good diagram over at PCMhacking, needed the 06 update version for the gen IV info.
 
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Jolls

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You can download the full VZ manual - if you do a quick search here you should be able to locate it. It has all the diagrams you need,
 

Drawnnite

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Well I have a bit of a breakthrough today.
Its electrical.
Now below is the interesting bit.

Had the scan tool on that can log all the sensors and give live readings
Drove past a few spots where the digital radio cuts out and the o2 reading fluctuated again.
Then it went back to the high constant reading.
Thought it was coincidental, instead when stopped turned the head unit off and lo and behold sensor fluctuates again.
HU back on and it reads high
HU off it fluctuates.

Does make sense as the issue started to arise after the HU was installed (previously was another Kenwood non digital approx 2017 model)
Its a Kenwood DDX9019DABS (so digital radio).
Could be the link.

Now to find where, what and how to solve it.
 

lmoengnr

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Sounds like RFI?
Maybe a shielded cable needed somewhere?
 

Drawnnite

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Yeah that could be the issue. Either RFI or the way something is connected up
Will start it tomorrow to have a good 8+ hours to not rush it
You'de probably have a chuckle to realise i was doing the readings while heading down to Autobarn to buy the fuel disconnect tools to do the manifold gaskets. Guess i now have those tools for later anyway.

There are a few wires that were tapped into so will end up checking they were in the right spots (ie the speed sensor wire)
Will also check to see if it happens if on fm/am/dab/ipod etc see if that can isolate it.
Unplug the aerials (DAB and FM/AM) individually and see if that makes a difference
check the earth wire is on the DAB antenna properly.
check the wiring runs to see if they could be causing interference.

Its opened a can of worms per say, but atleast we now have the equip (scan tool) to live read the o2s
makes a massive difference with scoping the info.
 

lmoengnr

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Yeah that could be the issue. Either RFI or the way something is connected up
Will start it tomorrow to have a good 8+ hours to not rush it
You'de probably have a chuckle to realise i was doing the readings while heading down to Autobarn to buy the fuel disconnect tools to do the manifold gaskets. Guess i now have those tools for later anyway.

There are a few wires that were tapped into so will end up checking they were in the right spots (ie the speed sensor wire)
Will also check to see if it happens if on fm/am/dab/ipod etc see if that can isolate it.
Unplug the aerials (DAB and FM/AM) individually and see if that makes a difference
check the earth wire is on the DAB antenna properly.
check the wiring runs to see if they could be causing interference.

Its opened a can of worms per say, but atleast we now have the equip (scan tool) to live read the o2s
makes a massive difference with scoping the info.
Is the DAB aerial an active aerial? I'd unplug that one first.
I was gonna offer my Tech 2, but the bloody thing isn't working...
Are your fuel line disconnect tools like these?
2021-01-04 15.01.33.jpg
 

Drawnnite

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Yeah, those SP tools ones and also the other X shaped scissor version. Got both just because.

This is the scan tool i am using:
Vident iLink400AU Single-Make Scan Tool - All System Diagnostics + Service Functions + ECU Coding (auscanners.com.au)
Nowhere near as good as the GScan at the mechs, but for my needs it does well.
If you want to check it out just let me know.

Plan of attack first is the speed sensor input as its easy to get to.
Then ill attack the DAB aerial as it needs a few dash pieces removed.
But its a tomorrow job now.
 

Lex

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Yeah, those SP tools ones and also the other X shaped scissor version. Got both just because.

This is the scan tool i am using:
Vident iLink400AU Single-Make Scan Tool - All System Diagnostics + Service Functions + ECU Coding (auscanners.com.au)
Nowhere near as good as the GScan at the mechs, but for my needs it does well.
If you want to check it out just let me know.

Plan of attack first is the speed sensor input as its easy to get to.
Then ill attack the DAB aerial as it needs a few dash pieces removed.
But its a tomorrow job now.
I bought that scanner a few months ago.
I can hook up the ecotec motor (aldl) & the 6l50 (obd2) to check the tranny out.

I also bought for programming the cluster. But doesn't work for vt, but will for ve up. So l was told, from where l bought it.
 

ephect

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Nice find Drawn, I've been reading the thread as you posted up, but you've pretty much covered everything I'd thought of to suggest. Would never have linked the radio interference to O2 sensor issue
 

Drawnnite

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Thanks guys.

Yeah the scan tool isnt too bad for the price.
Good for monitoring the sensors etc.

So have had another small break through today.
Wasn't the digital radio.
The speed sensor wiring from the HU was hooked up to a Purple/White wire at X211-7
Upon disconnecting it (i'd previously suspected it so had 2 crimp connections on it) and having the radio on it was fine.
Helped being able to monitor before/after the disconnection.
The readings are still a bit erratic but that could be down to the O2 being poisoned over the course of testing (probably 2000kms all up on it now)
However will give this sensor a clean likely tomorrow when the exhaust is cold with contact cleaner and monitor it (do have a new spare and the old one that was pulled out when the o2 was thought to be playing up).

Will keep an eye on this and see if it has actually fixed it.
However so far so good.
And figure out where the speed sensor wiring actually is (no i didn't do the wiring install) which is also purple/white and so far have found it to be X1-57 as the plug and position. Which is also to a plug right next to where it was tapped into originally. White plug with the provision for about 9 pins which 6 are pinned. Sounds like its an accessory plug.

Has been an expensive journey, All because i wanted a digital radio....
But i guess now having extractors from it isn't a bad thing :p
 
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