NefMoto

Hey guys.
In the middle of a simple immo off here.
Hot aired the 24c02 off the board read it and hummm its a little weird here.
I was expecting A0 but I am seeing a F0 in the locations to be changed?

Does anything think if I just went ahead and made it 50 in the main and backup and corrected the checksum it would be ok?

Thanks for any advice.

oops forgot the file.. :)

BTW its out of a 2.0 Beetle 06A 906 018 AB if anyone needs a 24c02 file.

In fact it is a little weird dump. It seems to be more of a M38x ECU that a M592 one. Anyway it should be easily tested on bench. Also I remember that 24C02 from M592 ECUs, allows to be read and write with a clip without desolder the chip. Also short the crytal to be safe and avoid CPU startup. From my experience that trick wasn't helpful with M383 ECUs.
Then test and reply.

It is 100% me5.9.2

I am thankful for the info. I tried to read it with my clip but couldn't get it to connect well.
Read first try once I took it off.
How would one test it on the bench to see it it was successful?

During my tests, M383 & M592 send the engine blocked by immobilizer code testing it on bench and or the eeprom error code if exist some checksum error. If everything is OK neither of this codes should appear.

Oh, yes of course.
I was misunderstanding what you originally wrote there.
I will finish it up and test it tomorrow.
Thanks for the input.
After some looking around I'm thinking this ECU might have a unitronics file on it.
I haven't even looked at the flash yet though.

I just have to be that guy.

M5.92

E=DBW

 ::)

May I ask why you changed
F0 -> A0 and not -> 50 ?

I was under the assumption
F0 = ?
A0 = Immo on
50 = Immo off

I had porepaired a file with 50 and then noticed you had posted up a file and it had A0.

F1Torrents basically you do not need to force hex 50 in that locations, please check out the attached pic, that I found here in Nefmoto forums....

Yes, I a aware of that pic.
I was under the impression that it needed to be 50 but it seems you are saying it just needs to be reduced by 50.
Either way I will test and see what happens.
Just my test clip is horrible for reading on the board so I have to take the chip off every time I make a change.

I ran some bench tests and without a car to test this in its hard to tell if the immo is on or off.

e2p removed- DTC for ROM ERROR
e2p stock file-No DTC for eeprom or immo
e2p with "A0" - No DTC for eeprom or immo
havent tested "50" yet

I checked the measuring blocks but don't see anything related to engine start permitted or not.

I guess my only question is.
Does the value just have to be reduced by "50" or does it have to be "50"
Is it just a coincidence that in a normal 24c02 immo off
A0 - 50 = 50  (that it just happends to = 50 )

f1torrents from my tests DTCs was seen after at least two ignition on-off cycles. About the immo off procedure my understanding is that you need to substract 50 to the 000C & 006C fields and we need to check checksum adding 50 to the inverse alternate fields 000F 000E & 006F 006E, and going back inverse again. The main issue is that all eeprom dumps that I have have A0 with immo on.

Change A0 to 50..

When you see A0 in 0x000 and 0x040, recalculated the checksums, when you see A0 in 0x000 and 0x060 / 0x070, then change A0 to 50 and not calc the sums, change it to 9E

Example :

0x000 - 0x040 ( Calc sums )

Original :
A0 FF 57 F4

Off
50 FF B4 F4

0x000 - 0x060

Original :
A0 FF 57 F4

Off :
50 FF 9E F4

Thanks for the info there.
I am familiar on how to alter the IMMO and CS
The questions was about the problem with the file having a
F0 to start with instead of a A0

So would you change
F0 > A0
Or
F0 >50

I understand from MK2-VRT comment that you need to change F0 to 50 for Immo OFF. I can't verify that because all the immo dumps in my small database of M38x & M592 files are "A0" for Immo ON.

Look at the differents in my file, there is not always A0, in this ecu you see 1x A0 and 1xFF..Change it simply to 50.

Regards,

I have investigating and find that it is right that 0x000C & 0x006C:A0 --> immo on, changing it to 50 --> makes immo off. But the issue is when we should make a checksum correction add/substract in locations 0x000E/0x000F & 0x0006E/0x0006F or just change location 0x000E & 0x006E with "9E". Check out the attached dump of a 06A906018AQ ecu.

Test it..

First is off ( 50 - 9E )
Second is 50 + Calc sums
Last one is a working off file for 06A 906 018 AQ

MK2-VRT I don't have the ECU but the last file is the Immo OFF file that I used in the past. I saw that many of the dumps that starts with 12 68 30 works with 50 + Calc Checksums and others that doesn't start that way uses 50 + 9E.

Could anyone tell me please how to read 24C02? I understand that via programmer, I'm using Xeltek but it always shows that 7 pin is not inserted (but it inserted for sure).
I read 24c04, 95040, 95p08, 29F800(400,200) before without any problems.
Actually I dont know what name of manufacture that produce this 24c02. Maybe thats the problem or maybe 24c02 was damaged...

A 24C02 you read the same as the 24C04.

Sure that hes make good contact on all the pins ?

And is it a 24C02 or you see another no on the eeprom ?

Pretty sure all contacts are ok.
But! Its a 24C02VM8 eeprom. I dont know what VM8 means. I choose as 24c02 into programmer soft, cause there is no 24c02VM8.

Trying to read with a clip on the board is hit and miss even with a good 3M clip.
Best to remove it and read/write.

Works 100%

I have tryied shorting XTAL to avoid MCU starts and also lifting VCC of 24C02 with some mixed results, but if the IC is good for sure, removing it should work 100%.

I tried to read it with a clip too, but it read only 00 00 00 etc. (empty file)
Then I removed it and soldered to soic8 adapter directly. Checked my soldering one more time. But my programmer still shows that 7 pin wasn't inserted.
Maybe smth wrong with the chip.

As a FYI to anyone like me who happens across this thread, the file up there labelled as 018AQ immo off has something wrong with it, which results in an EEPROM checksum error.

See my thread here for a working file:

http://nefariousmotorsports.com/forum/index.php?topic=6382.0title=