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Ive swapped the jumpers with the RW and others but no change. I also removed the 32k jumper.
I buzzed out the RW wire underneath and checks out ok.

I hope it wont need burning again as i dont have a burner. Thats why i love the idea of the NVRAM. No big deal if need be, at least its an easy fix.

Being able to datalog it, read a bin and the same issue on both banks its very unlikely to need the nvram reprogrammed.

If you have confirmed the rw wire is soldered to the correct locations and the solder joints on the rw jumper pins of the nvram are ok can post it over to have it checked out. Just flick med a pm.

This ecu was used as recent as last weekend on my mates car with this NVRAM so wire is in the right location.
Im going to borrow a mates VR manual ecu and fit my NVRAM to that. It has a write eire and a NVRAM (not VL400'S)

Could it be possibly an ecu issue? Besides the rw wire.

The rw line controls heaps, so if that was dead the ecu wouldn't run at all. But there is always the chance of odd ecu hardware issues.

See how it goes on the other ecu and let us know.

The NVRAM ICs will write-protect themselves once their internal battery drops below a certain threshold. This is both to reduce the chance of data corruption, and to alert the user to impending failure.
While the ECU is connected to the car, it's using the car's battery to sustain the NVRAM but switches to it's internal battery when external power isn't available.
It could be that your NVRAM's battery has been sitting *just* above the cutoff point for ages but because there's been external power available there has been no drain on the NVRAM's battery - but your recent shuffling between cars has caused the battery to drop below the read-only threshold?

Thanks Festy, another option to look at. The NVRAM was brought as a whole about 12 months ago 18 tops. Brought brand new from VL400.
If this other ecu still wont let me write i might take VL400 up on his offer to take a look.

I did come across a thread with a post from yourself where you mentioned the battery life.
Even if it was a few years old but never written to battery should be fresh? is that how it works?

Kind of - the datasheet describes a mechanism that only connects the internal battery the first time the device is powered up, but the chemistry of the cell (BR type, not the common CR) means it has a limited lifespan, regardless of whether it's used or not.
e.g. if a brand new NVRAM was left on the shelf for 10 years before being programmed for the first time, there's every chance it would immediately fail even though the battery had never been connected.

... but regardless, you should not have a problem after only 18 months.
That new flag in VL400's adx should help diagnose - does it report it's writable?

It says its in read only.
As VL400 said as i can download the bin and get live data from tuner pro. Most likely the NVRAM is ok.

The DS1245Y date code is 1317, so manufacture was 17th week of 2013. The battery would be slightly older than that hopefully Dallas source fresh stock before assembly of the ICs - would be very surprised if they would use old stock. Once the NVRAM is powered externally it will be writable even with a flat battery, it just wont retain the contents.

When I mentioned the NVRAM is ok and is unlikely to need reprogramming due to being able to connect/log etc, was meaning more so the bin is ok and not corrupt. If it wont work in the other ECU will get it sorted out

VL400 wrote:Once the NVRAM is powered externally it will be writable even with a flat battery, it just wont retain the contents.

I stand corrected, there is no mention in the datasheet of write protecting on low internal battery, the DS1210 has a feature where it blocks the second memory cycle to warn of a low voltage but it's not an actual write protect mode. That must have been what I was thinking of...

And that also explains why I've never seen a WP'd NVRAM, but have seen a couple that program and verify fine, but lose their memory as soon as they're removed from the programmer.

They will be read-only if the ECU's 5v supply drops below 4.5v (-Y) or 4.75v (-AB) but I think you'd have bigger problems in that case...