immo gets activated again after immo off

[frdnwr]

Hi Everybody ,

I've encountered this probelm several times , and i wonder whats the main cause ?

after turning immo off from 24c02 in audi 1996 bosch ecu 938/939 the immo turned back on... testing the eeprom i find the data changed,.. writing back the immo off dump, it works ... but soon it turns again ...
same thing happened in another Bosch ecu, i don't remember the number now, it was for fiat brava 1997 and it was 24c02 too .. and also in an old fiat fiorino ... exactly the same thing.


I did write protect on the chip ,.. to prevent the dump from being changed,.. but i still need to learn a better solution, or at least to know why did the dump change ..


The reason of making immo off, was that the car doesn't start, although key and immo matched , and i ve to use original dump on ecu to get it to work.. but it fails after some use ... from 2 to 5 days ..

Could it be a corrupted ECU?

[dimitar]

This is audi with a separate immo white box. Ive made several immo off without problems with programing new 27c010 but never with 24c02. Maybe you should remove immo box and tie two gray wires together so the diagnostic can work

[TULGEYWOODMAN]

Every time you do one, make sure immo box is disconnected or immowiore to ecu is cut

[frdnwr]

hi, thanks for the replies ..
I didn't try to immo off from the flash before.. i'll keep this in mind .. but ,.. I tried this procedure on other cars, and they worked perfectly..with no problems at all..


I tried it with and without immobox plugged,.. i spent several days working on each car with this problem . but i'll consider removing immo always from now on..

[peppery]

On fiat brava with 1.4 engine i have the same problem.i make immo off and after few days immo go back :) thats hapend on 2 cars
the problem was in ignition coil. all eeprom was damage. i change coil and make again immo off, then all was ok

[frdnwr]

sorry , what do you mean by the ignition coil? the coild around the ignition that transmits the transponder signal?
I'm confused cause ,there is another spark coil near the engine I guess ..

thanks

[tiger707]

which tool are you using to turn off the immo !

[frdnwr]

which tool are you using to turn off the immo !

ImmoKiller 1

[sepistar]

hi, thanks for the replies ..
I didn't try to immo off from the flash before.. i'll keep this in mind .. but ,.. I tried this procedure on other cars, and they worked perfectly..with no problems at all..


I tried it with and without immobox plugged,.. i spent several days working on each car with this problem . but i'll consider removing immo always from now on..


how did you solved?i'm in same situation.car started once,but just one time,afterwhere just if i remove the ecu for 10 seconds,then starts.i have removed the withe box but still the same.Car is a4 1.8 year 1995 ECU 0261 203 938/039
regards

[frdnwr]

I write protected the eeprom after immo-off, and the car worked fine, but i am not sure if this has no impact on the car's ECU..

I think this needs a different immo off solution,
also, try a different ECU if possible, ..

regards

[sepistar]

This is audi with a separate immo white box. Ive made several immo off without problems with programing new 27c010 but never with 24c02. Maybe you should remove immo box and tie two gray wires together so the diagnostic can work

can you tell me exactly wich wires?cause have the same thing,and i would try
regards

[sepistar]

can anyone take a look at this dump?it work but just one time after key pull out it not working anymoore,until ecu remain cca 10 sec. without power after the cart start again.
Audi a4 1,8 petrol no TURBO year 1995.BOSCH 0 261 203 938/939
8D0 907 557 C
can find the immo key of it?will try to start with immo box,when no faulty.
regards

[sepistar]

no one?please help!!!!!
regards

[omglol]

Have you guys tried to phisically protect the data on chip (24c02) by joining pins 7 and 8 to enable Write Protect on chip?