PicoScope 2204A For Automotive

Posted On Jun 20, 2021 |

The PicoScope 2204A is a really cheap oscilloscope, but can it be used for automotive applications in place of the more expensive PicoScope 4425?

PicoScopes for automotive use are in general really expensive. When we talk about PicoScope Automotive, a price comes in our minds around three to four figures with a dollar sign in front - $$$$. In this article, we are going to look at one of the cheapest oscilloscopes that PicoScope make and ask, how suitable is it for automotive use?

PicoScope Automotive Kit

PicoScope 4425A
PicoScope 4425A: the ultimate kit for automotive diagnostics.

The PicoScope Automotive oscilloscope is an impressive bit of kit. You get the nice box with all the different accessories inside, there are four channels, amp clamps and all the probes to go with it. The PicoScope Automotive software has some nice little features there to help you with automotive specific issues; like being able to access reference waveforms and custom probes ready set up plus the Automotive Diagnostic software. Those who are looking to buy the PicoScope Automotive kit will know that it can go well into the thousands of dollars, and that is not affordable for all. However, PicoScope do have a range of entry-level scope and they are very affordable; the 2000 series. At the bottom of this range is the PicoScope 2204A. You can get this scope plus some automotive grade probes for under $200. There are a few versions of it, but will it be enough to perform routine automotive diagnostic tests?

PicoScope 2204A
The PicoScope 2204A can be bought from $99!

PicoScope 2204A Specs

The PicoScope 2204A is a 2 channel 10MHz oscilloscope. There is also an Arbitrary Waveform Genertor (AWG) output which can generate a variety of customized signals; not available on the PicoScope Automotive scope!

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What’s inside the box?

Open up the box of the PicoScope 2204A and inside you get:

  • Quick Start Guide: A generic Quick Start Guide; the same one that you get with all the other oscilloscopes.
  • Oscilloscope: Quite a nice small scope. It has two channels, named channel A and channel B and the AWG output.
  • USB cable: The USB cable that connects the oscilloscope to the computer.
  • Leads (optional): These leads are not really what you need for automotive applications. They are designed for high frequency inputs and have a small hook tool on them. You cannot fit 4mm/banana type back probes.

What you want to do is get yourself some of the Hantek Automotive probes and they are really quite cheap. You can fit your back probes and alligator clips on them quite easily. You can also piggyback them onto each other. If you are using two probes and you want to take one reference point as earth, you can just connect them together.

PicoScope 2204A box Contents
The PicoScope 2204A can be ordered with or without the 'non-automotive' probes.

How does it work?

Head over to picotech.com and install the PicoScope 6 software. Connect the oscilloscope up and the drivers are automatically installed, and you are ready to go. Once connected, the first thing to do with the oscilloscope is to check the battery voltage. You should get a flat line at 12 volts if everything is working ok.

PicoScope 2204A Automotive Test

We performed a number of typical tests on a 2012 BMW 320d. We tested a digital airmass meter, a fuel pressure sensor in a ‘draw’ mode and ulitmately, CAN Bus! We used the Hantek HT30A Automotive leads with a 4mm/banana Back Probe and Alligator Clip.

Air Mass Meter Signal

Airmass Signal Test
Using back probe to capture the airmass frequency signal.

Starting with an air mass meter reading, we are looking for a frequency modulated signal. Be incredibly careful when using these types of back probes. Don't push the probe too far in or it will damage the connector. When you look at the air mass frequency modulated signal in Auto mode, it flickers between 5 and 10 volts.

Manually select a 5 volt scale to make sure you get a constant pattern on the screen and set the trigger already set, you see the little yellow dot in the middle. It's really quite stable and looks exactly the same as what you see on the Pico Automotive scope.

Airmass Sensor Signal Waveform
The 2204A has done a great job capturing the high frequency airmass signal.

Fuel Pressure Sensor Signal

Fuel Pressure Sensor Signal
Back probe connected to fuel pressure sensor signal.

Now we take a measurement of the high-pressure fuel sensor on the fuel rail and this measurement is going to be much slower than the air mass meter.

We will change the time setting to 2s/div to take a measurement over a period of seconds whilst we rev up the engine and watch the signal change. Again it's really the same as what you would see on the PicoScope Automotive set up.

Fuel Pressure Sensor Waveform
The time base is set to 2 seconds per division to observe the signal change while the engine speed is increased.

CAN Bus Test (High Speed)

PicoScope 2204A CAN Bus Test
Connected at the engine control unite to take a CAN Bus waveform capture.

Now we test the CAN Bus network signal. We take a reading of the powertrain CAN from the engine control module. Now setup channel A and channel B; you can use channel A for CAN Low and channel B for CAN High. Get the ground connectors piggybacked onto each other to share a ground.

Turn on channel B to get the two patterns displayed. In Auto mode it flickers ‘over range’ a bit, so you can put the voltage up a to 10 volts to stop that from happening. Reduce the time scale so that you get a better picture of what you should be seeing for a CAN signal, 50us/div is good. We can also set the trigger to the start of the message which is slightly higher than the rest of the signal. Here you can see the data package that was captured.

We can use the amplitude cursors to measure the voltage; all you have to do is drag the blue box down for channel A and drag the red box down for channel B and you get a little measurement box open up in the center of the screen at the top. This shows the voltage at the given points on the waveform.

You can do the same for the time cursors from the sides of the screen. The little white boxes start off in the bottom left-hand corner, and when they are slid across the screen, the time measurement is also displayed in the box. Pull another ruler across to measure the difference.

High Speed CAN Bus
The 2204A does a great job at capturing CAN Bus as this time setting.

Conclusion

The PicoScope 2204A is a great tool for the money and will help you diagnose most issues. It would be good to have 4 channels to give more flexibility. The 2204A will also struggle to capture large amounts of data that can be zoomed in to after; but for measuring real time signals, it’s perfect! The scope is also compatible with the same accessories available on the Automotive kit:

Hantek 65A Current Clamp

Hantek 650A Current Clamp

Hantek Secondary Ignition Probe

Hantek Coil On Plug Probe

Come and check out the channel to see the PicoScope 2204A in action where I use it to diagnose multiple issues!

Mechanic Mindset YouTube Channel