4.0L Scope Captures

I'm actually vaguely familiar with scopes, have used one or two a handful of times but mostly just "playing".

As much as I would like to understand what a scope is telling me my I have only a slight grasp of the concept and functionality without the knowledge training or experience to really put one to practical use or easily decipher what one is showing me.

So yeah, in short I'm looking forward to lurking here and maybe picking up a thing or two.

 

If you want to get into scopes watch Paul (Scanner) Danner's Picoscope Basics playlist, while he is using a Picoscope the fundamentals apply to most any scope. Paul is an excellent teacher, most everything I have learned about circuit testing, driveability, and scopes I have learned from watching his classes as well as Eric O (South Main Auto), Ivan (Pine Hollow Auto Diagnostics), and various others and from doing it myself.

 

This is correct. From a 3 point ninja star, to the current sweeping design with gaps.

 

SPD Signals are the same In and Out
Makes you wonder why they used the Combination Meter as a bridge to the ECM?

 

IDK, on the 14 diagram it shows a transistor in the Combination Meter that generates the SPD signal.

 

Well, it must be generating a duplicate signal?
Because they look the same to me

 

Nahh, the left one has a picnic table, the right one has an equal sign...also the right one has 2 Charlie Browns!

 

@Dm93 has a manual iirc? I don't think there is any conversion of the speed signal in those trucks. It comes right off No1 Vehicle Speed sensor as a pulsed waveform. In auto trucks the Skid Control ECU takes one of the rear ABS sensor signals and coverts it to a pulsed signal, assume similar to what is shown in the scope grab. The Combination Meter just cleans the signal and passes it along to the other components that need it. Apparently there isn't much 'cleaning' needed though haha

Think it was @Jimmyh explained all that recently in another thread

 

2012-15 trucks are different, they get it from the ABS ECU on both auto and manual trucks.
I'm working on a writeup for the P0500 code, coming soon...

 

Of course they are...

 

The 12’ model was the “red headed stepchild” of the 2nd Gen trucks.
Toyota decided to throw some wrenches in on us.

While I like the later models. I kind of like the simplicity of the earlier models.
No VSC, DAC, or need for zero point calibrations.

Dm93’s write up will be a good one.
He had me poking and prodding behind my glove box.

So, what did I learn?
That the glove box literally lifts off the hinges and comes out.
For 12 years I’ve been emptying that thing to replace the cabin air filter. Not any more.

 

Rookie move!

 

Basically they are the same as the 05-11 automatic trucks.

12-15 trucks still aren't bad electrically when compared to other vehicles of that year range and today's vehicles can have over 20 modules on just a base model vehicle communicating on 3 or more different data buses.

 

New Pico captures coming soon.

 

Neat! Thanks for posting.

 

Looking forward to more captures.

I've been debating dropping... uuughh.. $2K to $3K (depending on scope leads, differential probe, etc.) on a Pico 4425A for over a year now..

It's hard to justify that kind of cash for what is really a moderate-spec'ed 4-channel USB-backed scope. The actual waveform/trace performance in a 4-channel package can be had for ~$400ish on Amazon -- but the Picoscope Auto software is pretty far beyond anything else I've seen.

I might go with a HANTEK 6xx4-series 4-channel scope + Android 10" tablet + 3rd party "HScope" software from the Android/Google Play online store at a total cost of around $600 before probes. Only reason I haven't tried this cheap solution yet is the HANTEK is only 8-bit vertical resolution, vs. 12-bit (with 16-bit "extended capture mode") on current-model PicoScopes.

Here's what that solution looks like in real life.

https://www.youtube.com/watch?v=A7qc_gfGh00

 

Yea, if there was more interest I might get more motivated to do some more.

Yea I kicked the idea around for quite awhile but then an offer came from AESWave that I really couldn't pass up, I got the Pico 4425 Advanced kit for $2500 which is a bargain considering the same kit with the new 4425A Pico is nearly double that at $4410.

The only thing I've seen that even comes close to the Pico as far as detail and features is the ATS E-Scope, it's 8 channel but it's even higher coming in at $4700 for just the scope!

Another thing that some of the Pico scopes have that others don't is floating grounds which isn't a huge deal but it's handy for certain tests.

Really for most stuff any multi-channel scope with decent detail is sufficient, certainly better than not having one at all.

Another disadvantage I see with that one is with a max 40v input you would need attenuators for alot of stuff.
It doesn't really seem to be oriented to automotive use although I do believe Hantek makes an automotive scope, not sure what kind of support it has though.

 

Just did captures of the ABS Sensor signals, now we know how the ABS module knows which direction the wheel is turning. The ABS sensors are "smart", they internally use the magnetic sequence of the tone wheel in the bearing to determine the direction of rotation and output a different signal pattern for reverse rotation.

As you can see forward rotation produces a normal square wave.


Reverse rotation it adds a very short (< 100 µs) ~1v pulse to the rising and falling edge of the square wave.