Quick Tip: Ignition Coil Current and Voltage Comparison

Testing an ignition coil can be tested a couple different ways, ones with voltage, ones with current. 
 
And we could actually look at them both at the same time on the same screen and see how they compare. 

Let's walk through how to do that using this Hyundai behind me. 

All right, so to do this, we're going to use the guided component test function of the tool. 

Now, I've already IDD the vehicle before, so I'm just going to pull it out of my previous vehicles. 

There it is right there. 

And then we'll go into the engine system. 

We can see all the different systems here. 

We'll just go into engine and then I want to start with the voltage. 

So we'll go into ignition coil here and we have primary tests and now we see we have resistance, signature, current ramp etcetera. 

So in this case, I'm going to start on the signature test and that'll give me my voltage. 

We can see the connector view tells me where to hook up. 

Ignition coil negative black to a no good ground come down here and it gives me a good waveform as well. 

We'll hit view meter and that'll pull up where my voltage would be. 

Now I need to also look at the current. 

So I have a current probe attached to the battery positive on here as well, but I need to add a second channel. 
 
So to do that on the straighten we have up here we have 4 arrows. 

If I click on that it's going to bring up my settings. 

If I come down here, turn on Channel 2, I'm going to set Channel 2 to be a low amps probe at 20. 

And then I also know in this case I need a 20 amp scale. 

So we'll set that up and once we've done all that, I can bring it back to where we were. 

And then if we start the car, we should be able to see it. 

All right, there we go. 

Actually make it full screen here and we'll stop. 

All right, we can turn it off. 

Alright, so here's my both my voltage and my current. 

The voltage will be the top line, this yellow line here, and then the current will be the secondary green line right here and we can see where the voltage comes in and then the coil is then grounded to start charging up the coil. 

We call that dwell. 

When the dwell starts we can see as the current will start flowing in to the coil as well. 

Once the coil's fully charged and it's time to fire, we see the firing line on the yellow line and then we see how the green line then goes away because all the current would have gone with it out to fire across to the to the spark plug. 

Then of course we see the firing line here. 

We see a couple coil oscillations there at the end. 
 
Being able to see both what's going on with it voltage wise and current flow wise can help us understand what's going on inside that coil.