Unable to connect with car

[VASTech]

Thank You Kev! Really apreciate!

[victor2k]

Hello,
Can be added as a separate channel a OBD connexion with the car ,for engine speed monitoring, lambda sensor voltage or other PIDs in Pico Automotive?
Thank you

[Steve Smith]

Thank you all again for the posts and to you Victor for raising the suggestion of OBD data included with PicoScope

This is a New Feature Request that has been discussed and documented with the software teams but for now remains on the back burner given the immense activity surrounding the development of PS7

With that said, the technique you describe using a screen recording of PicoScope in conjunction with your scan tool works incredibly well with some advantages.

The case study here topic22195.html is one such example where this technique was used

I use a program called Snagit from TechSmith https://www.techsmith.com/screen-capture.html to not only annotate captures but to record numerous videos of the laptop screen.

The video below shows Snagit in action capturing scope data simultaneously with scan tool data in order to correlate events transmitted to the scan tool (serial data) with live data captured via the scope

SCAN TOOL AND SCOPE.mp4

Scan tool and Scope

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The real beauty of such a capture comes to life when playing back the screen recording where you can precisely locate areas of interest within the waveform and data displayed by the scan tool.

The video below demonstrates this technique where we focus on gas pedal position

SCAN TOOL AND SCOPE PLAYBACK.mp4

Playback and correlate

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After watching the video above we can immediately see the delay between data displayed by the scan tool and the actual live values captured by the scope.

Below we have manifold pressure (Channel B Red) at near 0 bar (gauge pressure) or near 1 bar (absolute pressure ) yet the scan tool indicates Intake Manifold pressure at 2489 mbar (Absolute)

Manifold pressure delay

Here we reveal the delay of the scan tool which could be improved by reducing the number of PID's displayed

Again below, we have another example of the refresh rate (delay) of the gas pedal position data in comparison to the scope (over 1 second)

Gas Pedal position delay

By no means is this an assault on scan tools, far from it.
Being aware of the delay makes for improved diagnostic decisions moving forward.

Whilst it would be awesome to see ODB data included and correlated with PicoScope software and data, I mentioned earlier there are advantages to this screen recording technique.

Using a screen recording we can correlate serial data from any ECU (not just Engine/OBD data)

This could be Transmissions shift solenoid activation captured with the scope and correlated with serial data

How about Climate Control?
Use the scope to capture Cooling fan duty, AC Compressor Solenoid duty and Cabin temperature whilst correlating with serial data

Once again all the above is food for thought but I must admit, if like me you have the short term memory of a Gold Fish, then screen recording of Serial data with scope data helps you to:

Convert voltage units (scope) to physical units (Scan tool)
Pause, forward & rewind captures to precise locations within a road-test/capture
Correlate multiple serial data parameters to your chosen sensors/actuators captured with the scope
Capture serial data not just for engine but for any ECU in which you can communicate
Assist with identification of saved PicoScope files and how they link to serial data events (If still recording whilst you save files)

I hope this helps, take care......Steve

[AndyM535]

I had a similar issue with an ELM interface connecting to a BMW bike last year. I could get the correct response using Windows Terminal, and in the race you could see NVH connecting but because it couldn’t read the VIN it just gave up. Steve logged it with support and I think they acknowledged it as a bug then left it on the to be fixed backlog.
I haven’t tried properly with the new version, but I had the PicoScope out today so did try it quickly. Seems to be the same unfortunately. Didn’t spend too long looking at it though, as the bike was outside and I couldn’t see the screen in the sun. I’ll give it a proper try in the garage tomorrow, and also try v7 and see if that’s any better.

[VASTech]

Definitely a Pico software bug on K-line protocol connections. On CAN-based protocols everything works perfect. Hope will be fixed in near future.
BR

[Steve Smith]

Thank you for the continued feedback

I have scheduled a day with Kev's with a K-Line car this Wednesday to gather the info required for the software team

Sorry this has taken so long, we will crack it

Take care......Steve

[VASTech]

Well Steve..., Have you "crack it" ? Did you managed to get something for Pico software team today ? Hope it ill be a software update soon! Looking forward to that!
BR!

[Steve Smith]

Hello again and thank you for your patience here.

Well, the irony here is that after obtaining a K-Line vehicle (thank you Kevin Ives) and using an ELM327MU lead (Version 1.1) I could communicate with the vehicle via NVH. The vehicle in question was 2002 Perodua Kelisa 1.0 litre where K-Line only was used for communication.

The video below is purely a live screen grab (not edited) from the test day where I have used Putty to command the ELM lead whilst simultaneously capturing the call and response (Tx Rx) of data between ELM and the vehicle using PicoScope.

I have then captured the same call and response during a successful connection to the vehicle via NVH See video here https://drive.google.com/file/d/1VHCsOK ... sp=sharing

Please find links to the PSdata files “TEST 3 & TEST 4” from the video above
TEST 3 https://drive.google.com/file/d/1VIFlP_ ... sp=sharing
TEST 4 https://drive.google.com/file/d/1VKYwBi ... sp=sharing

Please find below the NVH trace file from the successful connection of ELM to the vehicle seen in the video above (TEST 4) N.B Only road speed was obtained for reasons described in the video.

TEST 4 K LINE ONLY NVH SUCESS ON VIDEO TOO.txt

TEST 4 Trace

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The image below highlights the relevant data in the trace file above where we can see the ELM reset (ATZ) followed by NVH calling for VIN (which fails, as is often the case with older vehicles) and then successfully acquiring RPM

TEST 4 TRACE RX TX

Below is the trace file where I later obtained Engine and Road speed via ELM327MU (Ver 1.1)

TEST 5 KLINE SUCESS WITH ROAD SPEED.txt

TEST 5 TRACE RX TX ENG & RD SPD

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Below we have the PDdata file containing Engine and Road speed via ELM327MU (Ver 1.1)

TEST 5 NVH FILE WITH ROADSPEED.pddata

TEST 5 PD DATA FILE

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So, where to now?

I was using NVH version 1.16.0.5247 (which is here https://www.picoauto.com/downloads) and this could be worth retesting if you were using an earlier version.

Next would be to find an ELM Version 2.2 as you are using. I would be happy to test your device if we can make this happen?

I hope this helps, take care.....Steve

[VASTech]

Hello Steve, hello all!
Thank you for answer and to willing to help in this problem.
I was hope to make those tests on a VAG K-Line based car, because with those I have this issues.
So here is what i did again: I followed what you have done in PUTTY and make the same tests. In attached video you can see the results. If you have the possibility to make the same tests on a VAG car it will be great. I still thing the problem is in PicoDiagnostic software... Thank you!

[PicoKev]

VASTech,

Can you give me a list of vehicles (preferably with year and engine code) that you have have had the issue with and I will try and track down similar vehicles for Steve to continue the research on.

Kev.