'06 Ford Focus CAN Data Errors on ELM327 1.2a

**dmcglynn** · 01-02-2011, 11:57 PM

I'm getting "DATA ERROR" while listing all received CAN Traffic on my '06 Focus using a (probably generic knock-off?) ELM327 1.2a. Is my ELM so out of date that it's not understanding the data from these certain modules on the network? This is after changing my baud-rate to 115200, so the buffer didn't fill up quite so quickly, turning on headers, and running the AT MA command.

231 00 <DATA ERROR
3E9 00 <DATA ERROR
4B0 27 10 27 10 27 10 27 10
200 27 61 26 F7 27 60 80 00
205 00 <DATA ERROR
231 00 <DATA ERROR
250 00 <DATA ERROR
4B0 27 10 27 10 27 10 27 10
200 27 61 26 F7 27 60 80 00
205 00 <DATA ERROR
231 00 <DATA ERROR
3E9 00 <DATA ERROR
200 27 61 26 F7 27 60 80 00
205 00 <DATA ERROR
231 00 <DATA ERROR
433 00 <DATA ERROR
4B0 27 10 27 10 27 10 27 10
200 27 61 26 F7 27 60 80 00
205 00 <DATA ERROR
231 00 <DATA ERROR

4B0 & 200 are the only two modules I can ever seem to get any data from. Can someone shed some light on my obvious misunderstanding about how this is supposed to work?

Also, anyone know any sources for on-going reverse engineering of CAN data from these vehicles? I'm just getting into it, wondering if there was any place besides the bottom to start from.

Thanks!
Dave

**Vitaliy** · 01-03-2011, 06:25 PM

ELM327 expects the DCL to always equal 8, hence the error. Newer versions (IIRC, v1.3 and above) don't have this problem.

**remus08** · 01-04-2011, 06:14 PM

Hi,

I do the same experiment than dmcglynn and I've got some "Data error" (with a 1.4 version)

Code:

201 11 B9 7B 58 27 10 00 7D
230 00 01 66 00 64 00 0F 80
360 00 00 00 00 00 00 00 99
080 27 10 75 30 01 30 24
090 47 08 57 08 07 F7 17 D0 <DATA ERROR
210 FF FE 3C A4 40 00 24 <DATA ERROR

ELM327 datasheet talk about CAN auto formating with expect ISO 15765 CAN message, but I'm sure to understand.

Somebody has an idea? Thanks

**Vitaliy** · 01-04-2011, 07:44 PM

Can you guys turn on display of the DLC? "AT D1"

remus08, I think your problem may be unrelated. Notice how dcmglynn's <DATA ERRORs follow only the short frames. <DATA ERROR in that position may point to an actual CRC mismatch.

Vitaliy

**dmcglynn** · 01-04-2011, 08:43 PM

Thanks for the response.

DLC commands, both "AT D1" & "AT V1" are apparently unsupported on the version 1.2a ELM327 that I have. Both just return the familiar "shoulder-shrug" response of "?".

Thanks for the info though.

Dave

**remus08** · 01-05-2011, 12:58 PM

Right my problem is not the same. I didn't notice that actually I use my interface @230400 baud and it's a 1.3a version.

I will try to enable DLC, disable CAN auto formatting and make another measurment

**remus08** · 01-08-2011, 08:51 AM

Hi,

Ok, I've done the test again
This time, I've disabled CAN automatic formatting (command AT CAF) and enable DLC option

Code:

362.319922 > ATCAF0
362.340576 < OK
362.340611 < 
362.340634 < >
371.825821 > ATD1
371.857177 < OK
371.857211 < 
371.857233 < >
394.824137 > ATMA
395.109342 < 43078A005746800000
395.110296 < 200701E701E801E810
395.110475 < 20181BA87DC53D74007C
395.110651 < 23080500570064000080
395.111521 < 3608000000000008002F
395.113160 < 0807266B74BC0133AC
395.113340 < 0908C6CFD6E907451795
395.113504 < 2107FFFE3CA44000AC
395.114220 < 4B083D893D603D7D3D4E
395.114386 < 200701E801E801E810
395.114565 < 23080500570064000080
395.115299 < 3608000000000008002F

As you can see, everything woks well, so think to disable CAF option

PS: Now, I'm looking for to understand the data, if someone has some clue, that would be great!!

**Vitaliy** · 01-09-2011, 12:41 AM

No clue, except that the first three nibbles are the 11-bit CAN ID, and the fourth nibble is the DLC.

I would approach the problem thus:

1. Make a list of all IDs that you see.
2. Set up the filters to receive one ID at a time.
3. Tweak things (open/close doors, turn switches on/off, vary RPM, etc), and see if the data changes.

Best regards,

Vitaliy