Decoding CAN Bus Data Using the PicoScope

Using the Pico Scope, you can decode the data on most automotive data networks. This video specifically covers the data on high speed CAN networks. For a tutorial on how to capture this data, see my video called "Testing the CAN data bus with a lab scope."

[@wyattoneable]

That PICOscope is pretty amazing. Excellent explanation!

[@spelunkerd]

Man, I see your remarks everywhere I go, ha ha.

[@exmotorsports]

Absolutely amazing Justin... Had no idea the PICO had that function. Thank You for sharing that. 😉👍

[@mike-yp1uk]

Never seen this before. Learn something new everyday

[@RamirosLab]

The second message (Green), is very important. Is telling you how many Data Bytes is going to transmit. Note that in binary is (0110 = 6), that's why you have 6 Bytes instead of 8 Bytes.

[@JustinMillerAutomotive]

Thanks for sharing that information!

[@qzorn4440]

sweet video.. i was looking for Modbus RTU rs232 and found this CAN bus video. a spin off of CAN communications is used on the factory floor... good to know and thanks a lot...:)

[@linnashton7918]

Very informative. Great features in the scope. Excellent explanation

[@aplusautomotive]

Pico scope never fails to amaze me! Great video!

[@train4905]

Absolutely superb sir,thankyou.steve from the uk

[@thomashadden3552]

well that was bloody excellent.

[@farhadalizade4571]

Thanks.very good explanation

[@andrewk778]

Very informative. Thank you for sharing.

[@cheapers1952]

Great one Question how do I know which can module is which???

[@rbmwiv]

Great explanation.

[@catalinstefanteodorescu2996]

Dear Justin, Thank you for sharing this video. I wonder what type of Picoscope model you used in this video, allowing you to measure 10 seconds of data in 1 go. I cannot do this with my (cheap) Picoscope 2204A limiting me to max 20 ms of recorded data. Trying to increase the number of samples, will make the software no longer able to decode the CAN message. Is this related to the amount of memory the device comes with (8 kS for 22204A)? Thanks.

[@JustinMillerAutomotive]

I usually use the 4425 or the 4225. The amount of time that you can record for has to do with the number of samples you are requesting. If you request a higher sample rate, then you cannot record for as long because you are limited by the memory of the device. If you request a lower number of samples, then you can record over a longer time.

[@dzak8723]

Great video, thanks for posting. How do you get the binary to show up with the different colors and showing the stuff bits?

[@GrabbsRacing]

Awesome information thanks for sharing

[@robertomijango6207]

great video how explaint the dominant bite and excelent

[@russellmaguire-g1i]

Great Video! Can this be done on the PicoScope 7 T&M?

[@JustinMillerAutomotive]

Yes, I believe it CAN 😊

[@carlbylenga2541]

Very clear and informative . Why are all the packets shown in red and the "valid" column showing "x"?

[@JustinMillerAutomotive]

I have another video that talks about finding errors in the CAN bus. I think it will answer your question. kzbin.info/www/bejne/mpeznWWhjKd5Z7c

[@etibkel]

very good video! thx!

[@spelunkerd]

Brilliant video, I've been looking for this for a long time. Do you happen to know if the PICO offers a decoder for typical marine hardware communication protocols? My boat uses the old NMEA 0183 protocol, but new hardware is all NMEA 2000.

[@JustinMillerAutomotive]

Thank you. I wish I new more about marine protocols, but I don't know the answer to that question. Maybe you could contact Pico directly and ask them.

[@billyyoder8171]

Thank you Justin. Can you please give some examples of when we would need to decode the CAN Bus for diagnostic.

[@JustinMillerAutomotive]

By taking it to this level, you can determine whether the CAN bus is operating correctly and messages are being sent and received successfully--but that is about all. From here, you would need software with the correct file in order to translate these messages into English. That is basically what a scan tool does.

[@KristofBernaert]

hi Billy, any futher steps you found already here? I am in the same process with the need to analyse this data. All commercial Can-H & Can-L cable hardware-sniffers are pretty expensive. Thx!

[@saschasasa8089]

very nice video, thank u for that!

[@frundlemud]

very helpful !

[@aravindballa8544]

Thank you 😊

[@miltonscornertobylove5068]

Can the pico 7 do the same ?

[@nickayivor8432]

SUBSTANTIAL Justin Miller Thank you 👍 Very helpful video 👍 👌 Justin Miller From Nick Ayivor from London England UK 🇬🇧

[@treadmillrepair754]

This scope can decode the can bus in real time?

[@danielrdugan]

Any way of knowing what information came from? What module after it's been decoded?

[@JustinMillerAutomotive]

There are ways to do that. If you don't have manufacturer's files (which you would not, unless you worked for them), then you would have to manually decode the messages. This is a very long and arduous process. Often, this can be done by removing modules from the network or changing something, and then carefully comparing the messages to find differences. You wouldn't do this for fun. You would have to be very motivated.

[@rockyroberts7148]

Curious if you always ground to pin 5 at the DLC, or are there any instances when you would ground to pin 4? Thanks!

[@JustinMillerAutomotive]

You can ground on either pin. Ideally, they should both have zero volts. However, the real question is what is the voltage at those pins? If you are concerned at all about voltage drops on the ground side, you should verify that the voltage at each of those pins is within about 50mV of the voltage at the negative battery terminal. The negative terminal is always the best place to ground for most accurate readings, but once you have verified your voltage at pins 4 and 5, you can use them as your reference point.

[@geovani20091]

Thank you very much

[@ruinman8722]

great video. Can we reverse engineer the data to find out which unit (ecu) sends the packet?

[@JustinMillerAutomotive]

Yes, but it is very tedious to do it manually. There are software programs that can do it. In fact, that is what an OBD II scan tool is doing-interpreting the CAN data and turning it into readable information. OBD II data is public domain and can be accessed by anyone. For other network data, you would need to have the correct files from the manufacturer in order to translate the hexadecimal messages into something we can understand. The manufacturers do not usually give that out.

[@manuel7958]

Which Pico are you using?

[@supernmtube]

Anyway to translate the binary code into actual diagnostic codes? ie: p0300 etc.

[@JustinMillerAutomotive]

Yes, but it would be tedious. That is what a scan tool does.

[@supernmtube]

@@JustinMillerAutomotive thanks

[@rrmech11]

Very interesting

[@ClericChris]

Which pico is that. I need one of these in my life. Please don't be the $2500 one. If so does the Hantek do decoding too?

[@JustinMillerAutomotive]

It is the automotive Pico. There are other scopes that you can limp by on, but nothing compares to the automotive PicoScopes. No cheap scopes can decode the CAN bus like the Pico software, either. You can buy a 2-channel PicoScope with leads (without buying the whole kit) for a lot less than $2500. You can find a standalone scope or a starter kit on our website - CatchaWave.com. Call i you have questions!

[@jameybarisoff]

what about a 1995 lincoln continental j1850 style?

[@JustinMillerAutomotive]

CAN became the required protocol for the diagnostic network beginning in 2008. A few cars began using it a year or two before that, but not in 1995. Early for OBD II vehicles used the J1850 PWM protocol, which is a two-wire network on pins 2 and 10 of the DLC. If I remember correctly, the voltages switch from 0-5 volts.

[@JustinMillerAutomotive]

I meant to say "early Ford OBD II vehicles."

[@박준상-i5s]

LOL! Thanks hmm.. i don't understand why you select hysteresis value '480.8mV' Plz help me! (i'm korean) :)

[@JustinMillerAutomotive]

I think the 480 mV was just there by default. When the hysteresis is set to a lower number, the software will be more sensitive to errors in the CAN messages. If I want to detect ALL possible errors, I will set the hysteresis at zero. If I want it to be more fault-tolerant, I will choose a higher number.

[@박준상-i5s]

@@JustinMillerAutomotive Thanks for your answer! It helps me a lot to solve my wonderings. I will subscribe your channel! Thanks. haha :)