What is this

[BaBOo]

I went and do a superchip re-map, cos I had BMC installed.

but they have sort of delete my old ecu mapping and cant put the re-map one in for some reason.

heres what the tech guy told me

"the problem is that a whole chunk of the ecus memory is read during the sps process. This chunk is about 1/4 the entire program and contains all engine tuning information. The SPS system blanked this chunk before it decided to stop the programming process, and now the ecu has no tuning data at all, hence why the car will not start. I need to reinsert this chunk and then recalculate the checksums to suit the rebuilt read that we have so that the car accepts the new program. It is calculating the checksums (protection routines) that we need help with as they are tricky for the renault compared to say MINI cooper which also runs a similar variant of this siemens ecu"

What the F@@@ does that mean?

my car has been off the road for 5 days now, man do I pissed or what!

 

[McBunny]

it means he deleted your engine map and now cant fix it

when you program a flash device you cant lose power to it or it gets screwed as the entire program cant be loaded so you get a corupt ecu. most probably the only way to fix it now is to remove the actual chip and put it in a flash programer and start the thing again witha copy of someone elses or if renault will supply the image to them

 

[BenR]

this is the 172 yea?

no physical chip is used, its all done via the OBD.

I had worked with the superchip process and although i never actually fiddled the computer, they never had any problems. And the MINI was a billion times easier, plug in, press start, walk away then come back later.

 

[McBunny]

there must be a chip mate other wise it cant store the program it needs to be some sort of eprom it might be solderd to the board but there will be one

 

[BenR]

yup there is, i was just saying you dont replace or change any chip, but having read your thread again (been up for over 24hrs) i see what you are saying..........

 

[Frosty]

A checksum is this:

Say you have 8 bytes of data:

16 26 75 255 84 01 65 77

How does the system know that these 8 bytes are correct and not corrupt in some way? Queue the ckecksum. A calculation is performed on the 8 bytes and the result of this calculation is the checksum.

Simple checksum method is to add all values together:

16+26+75+255+84+01+65+77 = 599 (binary: 1001010111)

Then disregard all bits higher than 8th bit:

1001010111 & 11111111 = 01010111 (87 decimal)

This makes the ckecksum (which is usually every 9th byte in 8 byte checking) 87.

The result of the calculation is compared to the stored checksum by the ECU. If they are different then the data is corrupt - if they are the same, the data is valid.

Hope I havent sent you all to sleep.

 

[BaBOo]

yeah, its a 172

and I still have no idea what u guys saying...

basically my ecu is fcuked?

 

[Adams_16v]

i didnt think superchips were re-mappable anyway! so i was told when i rang about having one!

 

[Roamer]

Adam_16v, ok lets put this one to rest for good, on the clio1 16v chipping is done by physically changing a chip in the ecu, thus not remappable without taking this out and popping it is a eeprom writer again and blowing it with a new map, all time consuming stuff which is probably why superchips say it aint remappable.

Whereas the 172 is done by serial programming, so they just tell superchips HQ what they want to do to your original map (Ie up the fueling by 4% between 4000 & 6000 revs) then they download it and push it into the ecu via the serial link again..... so remappable (ish)

 

[BenR]

Quote: Originally posted by Frosty on 09 September 2003


A checksum is this:

Say you have 8 bytes of data:

16 26 75 255 84 01 65 77

How does the system know that these 8 bytes are correct and not corrupt in some way? Queue the ckecksum. A calculation is performed on the 8 bytes and the result of this calculation is the checksum.

Simple checksum method is to add all values together:

16+26+75+255+84+01+65+77 = 599 (binary: 1001010111)

Then disregard all bits higher than 8th bit:

1001010111 & 11111111 = 01010111 (87 decimal)

This makes the ckecksum (which is usually every 9th byte in 8 byte checking) 87.

The result of the calculation is compared to the stored checksum by the ECU. If they are different then the data is corrupt - if they are the same, the data is valid.

Hope I havent sent you all to sleep.

No, BUT IM BLIND!!!! lol