Vida CEM swapping

jcdillin · Post by **jcdillin** » 22 Feb 2021, 13:37

The PCB is finished and blanks have been ordered, once those and the parts come in i'll build up a prototype.

Post by **RickHaleParker** » 22 Feb 2021, 13:47

jcdillin wrote: 22 Feb 2021, 13:37 The PCB is finished and blanks have been ordered, once those and the parts come in i'll build up a prototype.

Have you published the schematic ?

Post by **vtl** » 22 Feb 2021, 13:49

gnalan wrote: 22 Feb 2021, 11:28 I'm still wondering why nobody is using DiCE to connect to the OBDII instead of trying to special build something else to do what It's already designed to do, which is to read/write to Volvo cars.

Just opening your DiCE and checking what kind of CPU is there takes more time than wiring up Teensy and CAN

Yeah, there is at least another revision using Renesas M32C. I'm not talking about complete fake yet working knock-offs that run on anything but STM32/M32C.

Plus you are jumping into a land of creating a custom software for a reverse-engineered device that is not easy. It may take weeks of hard word just before your new device prints its first hello world.

jcdillin · Post by **jcdillin** » 22 Feb 2021, 13:57

RickHaleParker wrote: 22 Feb 2021, 13:47
jcdillin wrote: 22 Feb 2021, 13:37 The PCB is finished and blanks have been ordered, once those and the parts come in i'll build up a prototype.
Have you published the schematic ?

No, I'm gonna see if I can I can sell it off to the highest bidder

jcdillin · Post by **jcdillin** » 22 Feb 2021, 14:01

The 4 PIN I2C Header was intended for use with this display. Also could just run it USB as well.

https://www.amazon.com/gp/product/B00O2 ... KRSVVE8B5F

Post by **gnalan** » 22 Feb 2021, 16:54

vtl wrote: 22 Feb 2021, 13:49 Just opening your DiCE and checking what kind of CPU is there takes more time than wiring up Teensy and CAN Yeah, there is at least another revision using Renesas M32C. I'm not talking about complete fake yet working knock-offs that run on anything but STM32/M32C.

Plus you are jumping into a land of creating a custom software for a reverse-engineered device that is not easy. It may take weeks of hard word just before your new device prints its first hello world.

I was working on doing some reverse engineering with the Renesas M32C/85 when I realized none of the opcode's were anywhere close to what the hex firmware file uses. That's when I took my DiCE apart and found the ARM chip, so I'm back to square one again.

jcdillin · Post by **jcdillin** » 01 Mar 2021, 14:06

Came across this while looking for some stuff on ECU programming. ECU flashing through DICE unit. I know it won't help with Pin cracking but still cool info.

https://github.com/prometey1982/VolvoTools

jcdillin · Post by **jcdillin** » 02 Mar 2021, 15:23

Success! I was finally able to crack the CEM on my bench. I had to change to a new style of CAN transceiver.

So now I've been trying to crack the CEM in my car, it gets to the point where it's cycling through the possible numbers but it only ever comes back with 99 or 00. I tried a few separate times with the same result. I really think some computer on the CAN bus is ignoring the sleep command and staying awake. I wonder if the sleep command needs to be sent slower and over a longer time period?

Trying to avoid pulling the CEM out of the car but may not have a choice now as I need to finalize my transmission swap.

Post by **vtl** » 02 Mar 2021, 15:32

Try to increase this: https://github.com/vtl/volvo-cem-cracke ... r.ino#L716

Also do you connect to both CAN-buses?

CAN_L_PIN is connected to CAN-HS- or transceiver's RX pin?

efe09 · Post by **efe09** » 02 Mar 2021, 15:34

hi jcdillin,
what do you mean " I had to change to a new style of CAN transceiver" ???
Can you please give more detailed information?