So my dads 2005 (October/November build) Saab 9-3 sportwagon has some serious issues with its ECU/ECM
Namely - loss of diagnostic comms, ECU odometer readouts totally wrong (e.g. 8 million kms), random engine stalls etc
Checked PCB and resoldered one component that was loose in the casing and one with a bad solder joint. fixed those 2 issues..reconnected and fan came on immediately, and random engine noises.
Bought a numbers matching replacement used ECM/ECU from ebay (however no idea if it was divorced from the donor car or not), borrowed a Tech2 from a friend with a saab v148 card
Tried just doing an add in tech2, got a message that the ECU wasn't correct for the car, tried SPS to reprogram via Tech2 remote, tech2 accepted the software, however programming failed at 6.6% line 17, needles on dash vibrated at same time. Battery was freshly charged (albeit not discounting that the battery is poor and causing a write failure)
Error screen received is
"Service Programming System (SPS)"
Version 2.053
Programming Failed!
Utility EDCG_3_1
Line 0A Operation B0 Errorcode 85
Press [Program] to retry or press [Exit]
tried a retry, no luck.
DTCs are showing no bus comms between Traction control and ECM, and traction control warning on the SID screen.
So going to try tech2 passthru mode tomorrow as its been suggested thats more reliable along with the fresh battery out of my car. Just hope the ECU isn't corrupted....Was advised to ask here for advice on a saab forum.
Can someone give me some advice regarding sorting this mess out please? (as I am rapidly feeling very much out of my depth here and would quite like to see this car back on the road )(As its a really fun drive) rather than scrapped as my father is currently considering.
I would be EXTREMELY grateful..
Thanks

Make complete BDM readout from the old ECU and copy it in the new ECU. Doing that you are making a clone ECU of the old ECU without the hardware problems.

Cheers
found why the old ecu was making the cooling fan go mad, a component soldered on back to front (was loose in the case so I had no idea which way round it should be...turned out backwards compared with its neighbour instead of same orientation...) and another with a cracked solderjoint.
Plugged back in, battery connected back up, no fans, turned key on, nothing...checked with tech2 and...the old ECU does not respond at all now...totally invisible to the car...tried unplugging and plugging back in and no life, just shows as missing...

Problem with the Add was that the car is on a late 2005 plate but is in fact a 2006 model year...my mistake, hence why the add didn't work.
Not realising this, I did a Reprogram ECU with Tech2 passthru and a new battery connected to the car, which succeeded and no more traction control messages, BUT then I started getting EDC16 Negative response messages.
Phone the local Saab indy for some advice to try and get myself out of this hole. Speaking to their tech I found out I made a mistake with the programming order on the replacement ECU(which thankfully was a cheap used item off ebay)
According to the tech, it should be Add, then SPS (software upgrade)...I did SPS then tried to do an add, seems one of his colleagues made the same mistake in the past and they ended up having to replace the ECU as it created a VIN number conflict within the ECU software (either brings up VIN Mismatch or EDC16 Negative Response and a string of hexadecimal digits (I got the latter response) ) and Tech2 wouldn't let them marry, unmarry nor blank the ECU, neither would it let them reflash the software (as the version numbers matched. Told I could reset all the modules and manually re-pair them but was advised it wasn't a recommended idea as all manner of stuff could go wrong.
So ordered another replacement and going to do it in the RIGHT order this time....and hopefully it sorts this issue out, might even send the original ECU off for a professional rebuild at some point....

I'm not sure 100% on this ECU but I know on others in past I have just removed the EEPROM chip from the ECU popped it into programmer and written a Virgin dump file so it's basically just like a new never coded one should be same principle here j would imagine i have in the past done the same method to the earlier model Saab when all keys were lost and I had to generate new new one the joys hope you get it sorted