Vida CEM swapping

Post by **RickHaleParker** » 12 Jun 2021, 05:57

ricked wrote: 12 Jun 2021, 04:35 30686819 does not exist

Typographical error.
30786819 is real.

P3 CEM part numbers:
30765624
30786819
31327994
31412971

PowerMatz · Post by **PowerMatz** » 12 Jun 2021, 14:37

RickHaleParker wrote: 10 Jun 2021, 02:16
PowerMatz wrote: 09 Jun 2021, 14:21 OK, will try tomorrow and send full log. Thanks!
If it still fails try changing the following in the code. You will find it near the top of the code.

#define SAMPLES 30 /* number of samples per sequence, more is better (up to 100) */
#define SAMPLES 100 /* number of samples per sequence, more is better (up to 100) */

SAMPLES 100 will take longer but it might get the PIN.

More SAMPLES is slower but more reliable. Fewer SAMPLES is faster but less reliable.

Should I remove the resistors at the CAN interfaces? I use a board with soldered ones. Are they needed? I read that this resistors are on the other side in the cars CAN bus already. I want to crack in car not at the bench.

Matthias

5ft24 · Post by **5ft24** » 12 Jun 2021, 15:52

My 05 V8 had to have the resistors while in car cracking. Need to disconnect the battery then measure resistance across CAN H h&l, and across CAN-L h&l If its 60 ohms, you don't need them. if its 120, you do.

Post by **RickHaleParker** » 12 Jun 2021, 15:59

PowerMatz wrote: 12 Jun 2021, 14:37 Should I remove the resistors at the CAN interfaces? I use a board with soldered ones. Are they needed? I read that this resistors are on the other side in the cars CAN bus already. I want to crack in car not at the bench.

I found that you do not need terminating resistors on the CAN transceiver or CEM cracker.
When bench testing you add terminating resistors to the pins of the CEM.

Measure the CAN line resistance at the OBD2 connector without anything connected. If it is 60Ω it is terminated correctly.
How connect the PIN cracker. The 60Ω drops to 40Ω. The extra 120Ω on the CAN transceiver is unbalancing the termination.

1(1/120Ω ) = 120Ω ; Needs one.
1(1/120Ω + 1/120Ω ) = 60Ω ; Correct
1(1/120Ω + 1/120Ω + 1/120Ω) = 40Ω ; One too many.

5ft24 · Post by **5ft24** » 12 Jun 2021, 16:10

I tried the cracker on my 05 V8 and without the resistors on the cracker, it couldn't crack the PIN even at 100 buckets, Key in position 0, I or II. Once I added the resistors, it would crack it every time, set to 30 buckets, Key in Position 0

Post by **RickHaleParker** » 12 Jun 2021, 16:14

Curiosity killed the cat.

Put the CEM back in Frankenstein, it is bricked. Don't know if the Flashing software erased it or if it picked up a hardware defect. Dropped a different CEM-H in and it came back to life.

Will need to crack the PIN then have Yagger synchronize the ECM and add keys and remotes again.

goonerm3 · Post by **goonerm3** » 13 Jun 2021, 17:40

goonerm3 wrote: 10 Jun 2021, 00:49 Can anyone tell me what would be best to run the cracker with cem in car?

CANBed - Arduino CAN-BUS Development Kit (ATmega32U4 with MCP2515 and MCP2551)
https://www.seeedstudio.com/CANBed-Ardu ... -4365.html

or something like this and a teensy 4.0 to run the cracker code?
OBD-II CAN-BUS Development Kit

https://www.seeedstudio.com/OBD-II-CAN- ... -2993.html

Anyone got any tips? Hoping to get my xenons in without paying 600$.

Post by **vtl** » 13 Jun 2021, 20:57

goonerm3 wrote: 13 Jun 2021, 17:40 Anyone got any tips? Hoping to get my xenons in without paying 600$.

You need Teensy 4.0 and 2x SN65HVD230.

PowerMatz · Post by **PowerMatz** » 14 Jun 2021, 14:04

RickHaleParker wrote: 12 Jun 2021, 15:59 Measure the CAN line resistance at the OBD2 connector without anything connected. If it is 60Ω it is terminated correctly.
How connect the PIN cracker. The 60Ω drops to 40Ω. The extra 120Ω on the CAN transceiver is unbalancing the termination.

1(1/120Ω ) = 120Ω ; Needs one.
1(1/120Ω + 1/120Ω ) = 60Ω ; Correct
1(1/120Ω + 1/120Ω + 1/120Ω) = 40Ω ; One too many.

Hello,

I measured 60 Ohm at both CAN connectors on ODB2. So I removed the 120 Ohm resistors. Tried it again with key in Pos 0. No Pin was cracked. Now I tried almost everything with no success.
Has anyone another clue for me now? I don't know what to do next because I tried all,

Best regards
Matthias

Post by **RickHaleParker** » 14 Jun 2021, 14:45

PowerMatz wrote: 14 Jun 2021, 14:04 I don't know what to do next because I tried all,

If your Cracker is still bread boarded. Check the connections. I made heavier gauge jumpers out of Paper Clips. It made a difference. You could use solid copper wire to make heavier gauge jumpers.

Which CAN transceivers are you using? Some people had trouble with the 3.3V CAN transceivers.

Do you have the Latency detect jumper installed? Some missed that because VTL forgot to include it in the original schematic.

The Red jumper is the Latency detector ( PIN #2 to #23, Both fourth from the end ).