Hi,


I'm pretty sure this is the correct forum to post this situation in.


The patient: 1996 328iC 2.8L M52


Short story: I bought a chip tuned DME , MS40.1 replacing an MS41.1. Great performance increase, car drives like 15 years younger. CEL is always on. No errors in any modules, fuel trims near perfect, no clue.


Anyone have this problem? Anyone heard of this problem?


Long story:


After chasing down idle problems and fuel trim issues for like three cold long months, including a copious amount of bad luck with 'new' parts, I finally reached a place where I got everything working. Pro tip: Don't buy badMAFs. Go with VDO or don't go. Really. Anyway, to celebrate my victory over the Vacuum Demons, I bought a cosmo CAI. Not much change really, someone on this forum mentioned I should really get a tune. Cool, always wanted to do that. Bought a DME with tuned chip from a reputable vendor, sells a lot to this forum. Box shows up from Eastern Europe, car seems OK, but...Yes forgot to remove badMAF. Went to see Russian friends in Gresham, got real MAF. Bang! Car freaking flies! I've had this car since 2000, almost 19 years. Honeymoon once again, plus the CAI goes "muuuughhh" when we're all excited. I'm 'test driving' and local streets smell like burnt rubber, radio is on, top is down.
I drive a Sport Luxury vehicle.


Except... the CEL is stuck ON. OK, test for everything in DIS--engine, trans, instrument cluster, every other module , no errors. Email vendor, describe problem. Yes, I will try to fix. Send me fullread. Um, ok, so I get yet another cable, get openMS41 Siemens flash tool (Kim's work). Fullread goes well (diag laptop is on spec). When I get the 'fixed' file, I flash it back to the DME. I bollocksed it at first, as I had insufficient voltage across pins 18-14. I fix, I flash. CEL still ON.


So to make sure I'm not crazy, I re-read the DME. The MD5 of the 'fixed' file and the re-read are the same. I know my 256K write has worked. Yes the 'fixed' file and the original read are different.


I tell my vendor, he's very helpful, he's doing his best, but is basically out of ideas. Me too.




My setup: dedicated Dell 620 laptop, baremetal RS232 serial port, Win XP SP3. TinyADS 20 pin cable from openlabs, DIS v44, V57 in Santa Cruz Ops unix VM. Eddy Abbas 6.4.7, INPA et al from ###-########.net. OpenMS41 flash tool with amazon K+DCAN cable for ECU reads/writes.


The farthest I could get with DIS was an 'engine lamp' test procedure. Tried the module, and it asked if lamp was flashing. It (CEL) was not, but it did turn off. Further into this module, DIS asked me about pin 20 from DME harness to CEl lamp. Yes it works, I don't believe that there is any connectivity problem with pin 20 (grey wire) from DME to lamp.


CEL went off with old DME (41.1) when it was supposed to.


Things I have not tried yet:
Swapping out old DME and see if exist condition is maintained.


I still have the 41.1 DME that was OE.


How badly would I brick it if I were to flash it with one of the 40.1 files that I have?


Could I use old DME and partial write the 'tune'?


If you are still awake, you can tell I'm new to tuning. I think it's cool, but I really just want the one I have to work.


I have some theories, but they are perhaps armature. EU tune? (US has CEL, EU not so much in '96)...should have been addressed in data file.


Physical problem with new DME?


If anybody has any experience with this situation, or any procedures I might follow I, and my tuner Dude, would really appreciate your input.


Thanks,




--------------------------------Beak