canbus

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pblunt
Newbie
Posts: 1
Joined: Mon Dec 08, 2014 6:39 pm

canbus

Post by pblunt »

Good afternoon OR morning fellow Pico helpers . Iam a relatively new to this so bear with me please, What it is that iam having trouble with, is the other day carried out canbus communication and cereal decode on ford fiesta with no problems. PROBLEM know is TRYED connected up to 2012 Audi A1 for canbus communication via breakout box pins 14 and 6 obviously, using channel A&B PICO PRESET. I had voltages on CAN high and low of 2.5 and 2 volt but no serial data .So I decided to PIn prob DLC pins 14 and 6 and chassis earth or signal ground on my 2009 skoda octaiva and had the same results just showed me flat lines but voltages around 2.2.5 volts on both channels very slight noise.So tried channels C&D on pico the same results, I cannot help but think since carrying out or trying to carry out serial decoding and using Maths channel (not connected at the same time to vehicle ) that I have reset or messed something up can anyone help me please . All vehicle showing no faults with communication via vcds What iam I doing wrong?

ronw38
OneWave
OneWave
Posts: 48
Joined: Sun Aug 27, 2017 8:00 am

Re: canbus

Post by ronw38 »

Hi This is not a case study situation u should be reporting on a fix not asking how to do it I realise you are seeking advise, silver bullet answers are rare, like so many posts or inquires on the forum, subscribers should at least use Pico, library, automotive, training, videos, and case studies, then ask for help supported by downloads of the problem captures, such a lot of time wasted, I feel this may turn off possible contributors. Maybe I'm right Maybe I'm wrong Ron W Cheers

ben.martins
Pico Staff Member
Pico Staff Member
Posts: 255
Joined: Tue May 16, 2017 1:02 pm

Re: canbus

Post by ben.martins »

Hello,

Thank you for your post and Ron W is correct, the case study section isn't quite the place to be asking for help. VAG vehicles commonly don't give up CAN related data at the OBD unless you have a scan tool connected and it is requesting data. This would explain why when you just scope these connections you only have the base CAN Bus voltages, which is useful information of course as this would prove wiring is good between the DLC and the Gateway.

If you have a Break out Box trying connecting to the vehicle whilst capturing CAN data with Pico. You should now see the expected result. If you don't have a Break Out Box more directly to an ECU or use a EWD to locate CAN BUS wiring and apply the scope there.

I hope this helps

Kind regards

Ben

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