Elec diagnostic scope for 2004 V70 turbo awd

Post by **jonesg** » 04 May 2023, 06:12

Is anyone using an oscilloscope, to perform diagnostics of the electronics on these volvos?

I'm about to buy a picoScope 2205A and test leads etc.

Vida and codes are great but usually only direct me to the parts cannon.

Post by **vtl** » 04 May 2023, 08:23

I have an oscilloscope (Rigol) and a couple of logic analyzers. Honestly, can't remember diagnosing anything that would require an oscilloscope. Usually the car says what it dislikes, and internet is full of old Volvo wisdom, which points your quickly to what you need to load into your parts cannon.

If you don't have a reference car that does not have the problem you're trying to diagnose with oscilloscope, so you could have a look at good signal (or otherwise having a sheer knowledge of how all the signals should look like), oscilloscope is of very little help.

But it is very nice to have one just in case, if you do electronics at home from time to time.

Post by **jonesg** » 04 May 2023, 10:07

Pico has a database of waveforms and a forum where you can upload data and get comments, i'd be hoping they know cars.
I don't mind wrenching, the elec part is what baffles me with these cars. Sending the CEM out to have it tested shouldn't be necessary with the right tool.

Post by **vtl** » 04 May 2023, 10:32

jonesg wrote: ↑04 May 2023, 10:07 Pico has a database of waveforms and a forum where you can upload data and get comments, i'd be hoping they know cars.
I don't mind wrenching, the elec part is what baffles me with these cars. Sending the CEM out to have it tested shouldn't be necessary with the right tool.

This was the reason of why, at the dawn of my Volvo voyage, I got a pocket sized oscilloscope. I quickly figured out anything non-bench sized, without a horde of knobs and toggles, is not a good oscilloscope. Also very little can be diagnosed with oscilloscope, and the problem is known to the internet crowd anyways, so they point your to a defective part based on the symptoms before you hit the "send" button

Really, I used a 300 MHz oscilloscope with Volvo somewhat heavily when I was debugging the CEM cracker. But it was not a good experience neither. Oscilloscope is primarily for analog debugging, while the task was all about timings of pure digital levels. I got a DSLogic Plus analyzer, which was just the right thing for the job: enough precision, protocol decoders, very nice UI.

99% of my elec diagnostics, if the crowd is uncertain, is done with a multimeter.

yanga001 · Post by **yanga001** » 04 May 2023, 12:51

A scope would have limited use outside of the high speed can, Low speed can, potentially the lin, and board level repairs. I have a sigilent one I picked up a while back and have never used it for repair. A good multimeter will do most of the work for an on cad engine diagnostic. That being said, if you are pulling out an powering modules then it may help however you may need to drive the communication signals from an external device. Tapping into the connections if you leave it on the car will be a pain as well.

Fluke multimeters or Klein tools are nice but pricey. Mastercrqft made some half decent ones as well.

As an example, I had no turn signal power and verified it with a multimeter. On ac mode it showed a voltage on one line and not the other. Turned out I had a bad splice on my p2 and switched to the correct line.

Get the wiring diagram for your car and study it. A good wiring diagram and analysis skills are way more important. For example, you can diagnose a bad can line by seeing all the modules affected. Can Networks are wired in parrallel and from my understanding a dead short on the network will pul l off multiple devices. Now I may be wrong having come from the p80, and these networks may have a separate plug for each connection, however the communication is in parrallel, that is all nodes can see what is transmitted and only the addressed one will respond.

Post by **jonesg** » 04 May 2023, 14:26

ok I understand.
I'll save my money for a car lift instead.

Post by **vtl** » 04 May 2023, 14:31

Oh, that one I'm dreaming for years and years!..

Post by **jonesg** » 05 May 2023, 02:41

vtl wrote: ↑04 May 2023, 14:31 Oh, that one I'm dreaming for years and years!..

I have my sight set on an ezlift, its not the cheapest ($2k) but it ticks all the boxes.
If my concrete was good enough I'd get a 2 post but replacing the concrete just isn't in the cards. I also lack ceiling room.
EZlift needs no hydraulic system or separate elec control, its actually drill powered. Portable, you can take it with you in the car.
No hydraulic rams or cross supports to get in the way as with scissor lifts.

https://www.ezcarlift.com/

Post by **vtl** » 05 May 2023, 06:37

jonesg wrote: ↑05 May 2023, 02:41 I have my sight set on an ezlift, its not the cheapest ($2k) but it ticks all the boxes.
If my concrete was good enough I'd get a 2 post but replacing the concrete just isn't in the cards. I also lack ceiling room.
EZlift needs no hydraulic system or separate elec control, its actually drill powered. Portable, you can take it with you in the car.
No hydraulic rams or cross supports to get in the way as with scissor lifts.

https://www.ezcarlift.com/

4400 lbs and 26" max lift height. Need twice more. Do they have an eztrucklift?

Post by **jonesg** » 05 May 2023, 13:29

I just ordered a 7" dewalt diamond concrete blade for my circular saw, I want to see if I can cut a section of the concrete out, if it goes well I'll do a pad and get a 2 post midrise lift.