Vida CEM swapping

[charlie13]

To remove . thank you

[RickHaleParker]

Just realized the Teensy 4.0 fits a Wide 28 Pin DIP socket. Useful if you want to reuse the Teensy 4.0 for other projects.

IMAG0289.jpg (1.95 MiB) Viewed 810 times

[RickHaleParker]

I know about the resistors are in the cem but I do tests on the table. I test CEM L, I have 2 pieces and the reading does not start, I guess I did something wrong with the teensy program? See .....

Some of the CEM-L will not read on the bench unless you comment out this line in the code.
#define CEM_PN_AUTODETECT /* comment out for P2 CEM-L on the bench w/o DIM */

Just add /* to the front of the line
/* #define CEM_PN_AUTODETECT /* comment out for P2 CEM-L on the bench w/o DIM */


The CEM-L is not a end node. On the bench, the four 120ῼ resistors go on the end node CAN pins.

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+12V power supply ==> CEM Pins E1 or E2 ( The large two pin connector in the fuse section )
Ground Power supply ==> CEM Pin D6.

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Diagnostics ports: No terminating resistors because they are not end nodes. Which means no terminating resistor on the CAN transceiver also.

Teensy HS-H ==> CEM Pin D:33
Teensy HS-L ==> CEM Pin D:48

Teensy LS-H ==> CEM Pin D:40
Teensy LS-L ==> CEM Pin D:55

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The four 120ῼ terminating resistors go across the end node pins on the CEM.
CAN HS end node 1: CEM Pins D:31 & D:46
CAN HS end node 2: CEM Pins D:32 & D:47

CAN LS end node 1: CEM Pins D:35 & D:50
CAN LS end node 2: CEM Pins D:37 & D:52

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I power up the CEM then power up the Teensy. Works for me on CEM-L & CEM-H.

[Evautos]

Update:
The transceivers I ordered finally arrived yesterday and I managed to have another try this morning. Both CEM cracked successfully using HS and LS CAN both connected on the vehicle and just HS on the bench (with the 120 ohm resistors still fitted to the transceiver board for CAN (which I was going to remove, but forgot in my rush to try it))
My original 10kohm jumper connection wasn’t great and the transceiver that I was using from an old pcm was a 4.5 volt minimum voltage, so the Teensy may not have been driving it correctly? Although it did decode the part number previously each time and got the first two bytes correct a few times too, so it was probably just my poor connections and maybe the lack of LS CAN not being connected and silencing it.
Thank you vtl and RickHaleParker for your hard work

[Evautos]

20220403_125300.jpg (4.55 MiB) Viewed 756 times

Interesting to see what it's doing.
With those 120ohm resistors in place the CAN signal looks pretty good at approx the correct voltages.

[charlie13]

To remove . thank you

[vtl]

My CEM-L goes into some sort of standby mode after like 20 ms if it sees no DIM on the bus, maybe other modules, too. I usually run the cracker without autodetect and power up the CEM when the cracker says "Putting all ECUs into programming mode.".

[Evautos]

The two CEM-L I have been using both seem to stay ready to communicate whenever. In the vehicle I could just connect and the programme would start identify and run without any ignition key input and even with the door switch state not changing. I know some vehicles wake the CAN up as soon as a door is opened or a proximity remote is detected.
I left the one on the bench this morning and forgot to turn off power to it and it connected straight away as soon as the programme started when I reconnected to take the scope captures.
The part numbers of the ones I have are 30728542.

[RickHaleParker]

What are the VCF files?

[charlie13]

Links to Vadis 2005 and Volvo EWD 2014D if someone doesn't. password via private message
Thank you for all your help! Teensy 4.0 works. For P1 and P2. In fact, the can circuits were faulty after assembling the 1050, everything works