Vida CEM swapping

jeffbolem · Post by **jeffbolem** » 22 Jul 2023, 20:50

alevol wrote: ↑21 Jul 2023, 00:41 I am afraid it will not be that easy, that you change CEM and get no warnings. The ECM software will keep waiting the transmission to respond.

I have an m66 ecm tune that I’m going to flash on first before I rip out the cem and change the params there

dikidera · Post by **dikidera** » 23 Jul 2023, 02:01

After digging for some information, after 2005 or after 2006, there was a software update for the ECM and ETM, especially the ETM, which exported the TPS1 and TPS2 values as read by the ETM which allowed for the tests we see in the xml script a few pages back. Otherwise all the diagnostic data is internal to the ETM and probably isn't even alerting the ECM so there would be no codes. This is the conclusion I came to based on a post on another forum by a russian member, specifically for 9458346 diagnostic version of my ETM.

Of course there could be hidden commands to read them directly from the ETM, but I have no firmware to reverse engineer and see.

Yesterday I had a new problem I've never had, it was either the throttle valve not opening or a delayed engagement, but after going from Park to Drive, nothing happened, the car did not move or rev.

oscilloscope · Post by **oscilloscope** » 23 Jul 2023, 05:44

all i had planned on trying to understand how the synchronization works on the volvo's where its relevant ( which is pretty much all of them) if I where given the opportunity to obtain some source code for the synchronization process for the sid807 , but i have to pay for it through a not so trusted source. should i go through with it? , i plan to make it open source.... i have asked the same developer for ALL of the synchro software avalible for the volvo system's i am awaiting the cost of that. again i am planning on making it open source again.... thoughts , idea's & a general ribbing go ahead.

dikidera · Post by **dikidera** » 23 Jul 2023, 10:17

@rkam, the Dynamic records work perfectly, except one issue I cannot find out why it's happening. 7A A6 F0 00 04(fast repeat until stopped), this is what I do, but it always stops after 5-6 seconds and I have to do 7A A6 F0 00 04 again and again each 5-6 seconds. Why does it always stop?

I also tried 7A A6 F0 00 32 but most often get

can1 01200021 [8] CC 7A 7E A6 23 00 00 00
can1 01200021 [8] CC 7A 7E A6 23 00 00 00
can1 01200021 [8] CC 7A 7E A6 23 00 00 00
can1 01200021 [8] CC 7A 7E A6 23 00 00 00
can1 01200021 [8] CC 7A 7E A6 23 00 00 00
can1 01200021 [8] 97 7A E6 F0 00 03 F4 12
can1 01200021 [8] 11 00 4E 04 86 00 FF FF
can1 01200021 [8] 54 0E E3 8E CB 00 00 00
can1 01200021 [8] CC 7A 7E A6 23 00 00 00
can1 01200021 [8] CC 7A 7E A6 23 00 00 00
can1 01200021 [8] CC 7A 7E A6 23 00 00 00
can1 01200021 [8] CC 7A 7E A6 23 00 00 00
can1 01200021 [8] CC 7A 7E A6 23 00 00 00
can1 01200021 [8] 97 7A E6 F0 00 03 F4 12
can1 01200021 [8] 11 00 4E 04 A8 00 FF FF
can1 01200021 [8] 54 0E 4C 8E CB 00 00 00
can1 01200021 [8] CC 7A 7E A6 23 00 00 00

rkam · Post by **rkam** » 23 Jul 2023, 16:02

@dikidera
I haven't tried datalogging yet, so I don't know if it is normal to repeat the request.

The ETM I have on my desk does not need and SBL to read data with checksum command in programming mode.
I can also read with BB-command.

12 BB 00 40 00 10 reads 0x10 bytes from address 0x004000

dikidera · Post by **dikidera** » 23 Jul 2023, 16:27

Thank you, it would be nice for me to dump the ETM. I wonder if anyone knows the MCU inside.

For datalogging, I had to manually restart the python app I wrote, I almost crashed...twice as I had to do Ctrl-C and python <app.py>, as for some reason repetition stops after a few seconds.

I have not yet written code to export CSV, but I will. In my simple datalogging(dataglancing if we are to be accurate), the throttle angle does not change considerably relative to the same Accel pedal position, but what does happen is the gearbox is trying to maintain the same gear going uphill, and in some instances going into 5th gear or not dropping a gear for easier hill climbing.
With datalogging I can then also log how the gearbox behaves, I had an unpleasant situation where I idled for 15 minutes in Park, then went into drive...and nothing happened, not even after pressing the accelerator(no rev), and then a very harsh and delayed engagement.

rkam · Post by **rkam** » 23 Jul 2023, 16:49

My Magneti-Marelli ETM could be disassembled as 68330.
Here is D2 command list from mine:
012DC2 cmpi.b #$A0,d0
012DC6 beq.s loc_12DFA
012DC8 cmpi.b #$A1,d0
012DCC beq.s loc_12E28
012DCE cmpi.b #$B9,d0
012DD2 beq.w loc_12E56
012DD6 cmpi.b #$BB,d0
012DDA beq.w loc_12FA6
012DDE cmpi.b #$BA,d0
012DE2 beq.w loc_130C4
012DE6 cmpi.b #$A5,d0
012DEA beq.w loc_13194
012DEE cmpi.b #$B8,d0
012DF2 beq.w loc_13310
012DF6 bra.w loc_13460

dikidera · Post by **dikidera** » 23 Jul 2023, 16:53

Thanks. I will work on getting datalogging going tomorrow, and see if I can dump the ETM.

3oh6 · Post by **3oh6** » 25 Jul 2023, 17:19

So I've just read right through this thread, but I went backwards from the latest posts and I've confused myself

I have a 2008 C30 (P1?) that I'd like to get the CEM pin from. What is my best way to go about this currently? I have a dice cable - is it possible to retrieve the CEM in P1 cars through the OBD port? Or will I have to remove the CEM and do it on the bench with an Arduino?

Thanks for any help

Post by **vtl** » 25 Jul 2023, 17:41

Teensy will most likely crack it over OBD.

Vida CEM swapping

Re: Vida CEM swapping