Another Crank No Start | OBD2 No Comm + Xmas Tree Inst Panel w/Bonus ‘It hasn’t run in months’

Thank you for looking out because it is just the thing I tend to overlook I watched one of the videos (in Chinese, of course) on the Hantek site for Canbus testing and followed what they did and grounded at battery

Here's a video version of the oscilloscope attempt from last night:

Everything is being difficult; there should be a link in the attached txt file.

Let me know if not accessible.

All settings were just the default ones on the scope.
Oscilloscope was connected to CAN at the ECU and not at the DLC. I'll go to the DLC/Breakout Box when I go back out.
I also refastened the big behemoth brake connector because without it, only one of the channels appeared.

I'm going to try and bail early from work so I can follow the steps in the instruction video. I actually watched it before and had it saved as a favorite, but at the time wasn't sure what to do with it lol

 

Video says it was removed by the user but from what I saw on the picture you posted yesterday it's obviously not a good CAN signal, we need to unplug stuff until it gets better.

I'm not really concerned about talking to anything on the CAN Bus at the moment except the PCM, once we get that talking and get the truck running we can go after the other systems.

 

The top 2 look “better”.

I don’t know if we’re seeing the 2.5v live between the highs and lows or what?
What voltage scale are we on?

https://youtube.com/shorts/CmYUPZjrXoU?si=JU4nuZfnvynNlmVs

 

Looks like the top ones are reference waveforms?

 

I think it was reference on top. I’m out here poking around now. Slowly. It is COLD out here

 

Had to hunt down battery charger and get it hooked up.
1.) Is it ok to have chatger connected while troubleshooting comm issues?
2.) uploaded another vid using some screen capture freeware. Everything connected on truck with me just clinking a couple of screens. Please forgive the music that apparently came with the free package; I didn’t know it was capturing.
3.) I would need to watch the other can bus troubleshooting vid to try and decipher what I’m looking at or if settings need to be adjusted….should I still try unplugging modules 1 at a time?
4.) if so, what is acceptable protocol for disconnect modules? Is key off ok or do I have to go full on battery route each time?

I’ll save the airbag one for last ?



https://youtu.be/IZmok5vsKNc?si=wmPbZZ4sU026jCQz

 

Yea your fine doing that, just note you may have a bit more noise in your signal captures.

Yea there's really not much, just the Steering Angle Sensor, Yaw Rate Sensor, ABS, and SRS (Airbag) modules.

Key off is fine for everything except the for SRS, for that disconnect the battery and wait a few min.

 

I tried the ABS and the Steering one, and the ABS one made a small difference. Didn't have the capture on when I did it because I clicked an audio only option. I'll get a capture tomorrow. The coldness in my hands and those Toyota connector clips do not mix, so I'm back inside for tonight. I'm getting more familiar with this scope and settings; I'll read up more on it tonight so I don't take so long tomorrrow hopefully.

Should I leave the modules unplugged as I progress in case <deep breath> more than one module were zapped?

 

Yea like I said my main focus right now is to get communication with the PCM and after that get the truck running, once we do that we can go back and get other things sorted as needed. Hopefully not too many more things are fried but we shall see.

 

I would suggest using the same settings for every measurement moving forward, unless there is a reason to modify them. That way we have apples to apples every time and eliminate variables. That screen capture software worked surprisingly well too, way better than a screen shot.

Both Ch 1 and Ch 2 look good at 1 volt/div. Id suggest somewhere around 50-100 us/div on the horizontal zoom. Maybe @Dm93 can give a little guidance there? Just enough so we can see the waveforms without being too zoomed in or out. Also suggest turning the Display Grid back on as it makes the major divisions pop out a bit more. Although the Vmax readout on screen helps with that too

 

I think the settings are fine for now, being the entire bus is screwed up we don't really need alot of detail. It should be pretty obvious when it goes back to normal, right now our bias is basically at ground and the signals are terrible.
We are looking for the bias voltage to go to 2.5v and the signals to look more like square waves.

I'm not sure about the Hantek but on most scopes you want a longer timebase during capturing and then after you capture you can zoom in for detail if needed but in any case it's good where it's at for the testing we are currently doing.

 

Yeah, I noticed that too

 

Hello again - I'm heading back out fully equipped, and to make sure I have this right:

• I'll leave the scope on the default settings for the Canbus testing, maybe adjust horizontal zoom setting to somewhere around 50-100 us/div. Whatever the setting, will leave it the same for anything tested.
• Test with all ECUs connected for baseline.
• Disconnect the relevant ECU - test for 1 (?) minute. Is that long enough?
• Leave that relevant ECU disconnected and move to the next one. In other words, don't plug it back in when done.
  • Do airbag first since battery is disconnected.
  • SRS (Airbag)
  • Steering Angle Sensor
  • Yaw Rate Sensor
  • ABS
• Combo meter will have resistor in C9 connector.

Here are some of the settings on the cheap scope that I can add to the screen if you think they are of any value:

This is vertical....





It's what produces some of these numbers in a more effective order if I add them properly:




Last, there is an option to export some kind of data from this thing, but it was in a format I didn't recognize. When it is set up, I'll send info on it if there is any benefit to collecting that.

Thanks again - be back in a little while.

 

And I'm back. Here are the things to be unplugged:

The steering one I was questioning because it seemed to look different in service manual.

The one in the middle:





Airbag - underneath where stereo and A/C controls are





Dirty Yaw - I've vaccumed twice under here if that is any testament to the dirt in the carpet.







Last, DRC was the file format available for data export. Can't say that I've heard of it.

Also, these are unplugged from the driver's seat, in case that affects anything. I don't think it does.

 

I'll look closer at this later I'm still baling hay but did we get the CAN fixed?

 

After unplugging all 4 modules, I can see the ECU in Techstream. Is this part of what we are after?

 

That's that main goal, now to see about getting it to run.

 

That damn SAIS......
I hope that clears once we get it running.
This woman needs a break.

You're getting there OP. Don't give up now.

 

Let's make the truck run then we can deal with the other issues as they arise.

 

No doubt. But that is a limp mode code.
I just hate to see that.....it's like another kick in the face.

Agreed though, get it running first.