Checking and burning data from the Dallas chip DS1230AB-200

[Dalamar]

I found out something that others might find useful with the Dallas chip. I've been sorting out a spare ECU for my mk1 Tuscan and I bought an MBE 941 ECU with an old Dallas IC and no EPROM IC. I sorted out the ECU IC and wondered how good or bad the Dallas IC was (this is the IC that stores the adaptive map info). I could have run the car with the spare ECU, let it run up to temp and settle out with the adaptives, then pull the battery terminal for a few secs and see if I starts up again fine and runs smoothly from the off. In other words, seeing if the Dallas IC retains its memory.

I have a TL866 programmer and I was surprised to see that the programmer could read the DS1230 SRAM IC.

I read my original ECU Dallas IC and was able to copy this info into my spare ECU Dallas IC. Car ran fine on the spare.


I also had another old Dallas IC from an eBay purchase and read the info from that. However, I noticed that if I re-read the info off that IC then it would change over time and this would be reflected in the Checksum. See below pics.



So this is a method to check if the internal battery of the SRAM IC is OK or not. Surprised to see that the Dallas ICs from both my original and spare ECUs are still OK after 24 years! They both retain their info fine and produce a stable checksum.

The Dallas IC date code format is year followed week number. So the chip pictured was manufactured in the 27th week of 2000.

[Adrian@]

This is interesting, our Tamora purchased 2 years ago at 21k, had a history of battery changes (5) which I attributed to the car simply not being used, but I have had a glitch recently where the windows were cycling through the last few seconds of it's closing sequence, which was left overnight, before the battery monitor warned me, left longer, it would of drained/destroyed the battery.

Initially I had issues with the Dallas chip and the car not retaining a stable start up (Jason mentioned the chip and a 10 year expected life, with concerns over jump starting the car given the replacement batteries (a 2003 car with a 0031 dated chip). In all this the new chip cured the issues.

I think I am right in saying that the new chip has a bridge that burns out on first plug in, so it is possible to buy one and it has a good shelf life until you use it (I do not have the knowledge/tools to check one as you have).
A@

From you post... was there a date to the failing chip?

[Dalamar]

Yes it’s the one pictured above and you are correct about the battery only starting to be used on first activation.

The other two Dallas chips I have are old ones both marked 0027C 119057. Interestingly, my ECUs are serialised consecutively.

[Adrian@]

What has amazed me is that I spoke to more than several TVR MBE knowledgeable people, some that also offer chips (and I know have tools to copy etc.) and no-one mentioned reading the chip for it holding the data like this. The TVR ECU is so old now, that my feeling is that there is zero interest outside TVR 'world' for it. A@

OP, I was trying to look at the 2nd list as an image and this does not come up...

Edited by Adrian@ on Thursday 21st March 14:07

[Dalamar]

Adrian@, the second image seems to open OK for me. All that I was trying to show with that image is that the checksum is changing every few seconds. In other words, the data isn't being held constant over time as the battery has been depleted and the memory just has random ever changing noise in it.

[Adrian@]

Ah, It does now appear, and as you say, what is expected, when it has a flat battery.

I might need to take a curve on getting the tool and software to understand it better. A@

[Malcster]

I purchased one of the replacement ECU chips from TVR Power with the decat map on them.

Be really interested in what they have actually changed in terms of the map on the chip. Might see if I can pick up a reader.

Edited by Malcster on Wednesday 27th March 21:07