I think I had an ah ha moment, but it might have been a bad time to have it.
I was testing a vvc solonoid, had it out of the car and it had no movement when I out 12v to it. I put it back in the car, did the test again and got a little smoke out if it. I think the problem is that since the part was not working, there was no load in the circuit and I may have to buy a pcm now. Now I'm thinking I should have used the scan tool to command it or put a test light in line.
I'm quite sure a test light won't carry enough current to operate a vvt solenoid. Was the pcm connected to the solenoid when you power probed it in the car? Did you give it power or ground?
It was connected. When I did the second test I back probed it.
I think the pcm is ok since datastream shows output to the solonoid. Dc and activation.
That info must just mean that the computer is telling it to do something but doesn't tell you if the part is working? Is that correct?
My thought process was this:
Dtc said intake vvc circuit issue. I commanded the solonoid on/off with my scan tool and felt clicks on the exhaust solonoid but not the intake. I thought I'd bench test it so I took it off and put 12v to it with the power probe and it did nothing. I put it back in and back probed it again testing with power probe, and That's where I ended up.
It is possible that you may have done some damage. I love my Power Probe (I have a PPIV), but I don't like using the rocker switch on a component that is still connected to the vehicle. I use it mostly to check voltages and to have a known good ground with me when I am testing.
Most of the time I prefer to command the component on with the scan tool (if possible) and use a scope or multimeter and backprobe to look at the signal/voltage change (this is what I would do if I were in your shoes). Other times I will command it on and connect a test light in place of component to make sure there are no voltage drops.
You could still connect a test light to the solenoid connector and use the built-in directional test? I'm not sure what car you're working on, but most VVT solenoids are power side switched, so look for pulsed power on one wire, and steady ground on the other. That'll tell you if the circuit is still working or not.
Is the intake solenoid code a hard fault? As in, if you clear it it comes right back? You could also substitute the test light in the circuit and see if the code now stays away. Be very careful when doing this, and don't let the pins short to each other.
You're correct in your thinking about the scan data. The scan data can show the command taking place, but that doesn't guarantee that any current is flowing.
If you've got the Power Probe 4, you can use it in "driver test mode" to take the place of the vvt solenoid, then command it on with the scanner and watch the power probe
noah just told you how to do it. thats one way. if the scanner doesnt have a command for that your going to have to drive it for the pcm to control it. itll usually do it under load. perhaps pierce/backprobe control wire run a long wire into the passsenger compartment hook it to the tip of your power probe. and look for a control
Oh, I see. Is it not enough to see the values changing on the scantool when I look at the vvc solonoid pids that who when it is active and not and another that I believe was a % of it's position? I saw that this values were changing as I got it some throttle in park.
Thanks for your help with this. I feel like this stuff will eventually click if I keep watching the videos and reading the book.
Tutti57 wrote: Oh, I see. Is it not enough to see the values changing on the scantool when I look at the vvc solonoid pids that who when it is active and not and another that I believe was a % of it's position? I saw that this values were changing as I got it some throttle in park.
Thanks for your help with this. I feel like this stuff will eventually click if I keep watching the videos and reading the book.
Sent from my Moto G Play using Tapatalk
That's all the proof I would need
I think you're good to go. I thought you were looking for more test ideas, that's why I brought up the driver test wit the PP.
Tutti57 wrote: Oh, I see. Is it not enough to see the values changing on the scantool when I look at the vvc solonoid pids that who when it is active and not and another that I believe was a % of it's position? I saw that this values were changing as I got it some throttle in park.
Thanks for your help with this. I feel like this stuff will eventually click if I keep watching the videos and reading the book.
Sent from my Moto G Play using Tapatalk
That's all the proof I would need
I think you're good to go. I thought you were looking for more test ideas, that's why I brought up the driver test wit the PP.
I appreciate that though. Good to know that test. I think I've got a better understanding of the tool now. I'll be using that rocker switch only with the components on the bench from now on.
I just rearranged my garage this week too and now my scope will reach the vehicles, so I plan on getting some learning on that now.
When I had a Power Probe 3, I got in the habit of tripping the circuit breaker right after I connect the tool to the battery.
This serves to:
1) ensure you cannot accidentally apply power to anything
2) prove that you have a good ground connection to the battery.
Now the Power Probe 4 has a circuit breaker that rests itself, so no more safety!
This latch is a handy accessory for keeping power applied, or making it more difficult to hit the rocker switch. It does make it difficult to apply a quick, momentary power.
Noah wrote: When I had a Power Probe 3, I got in the habit of tripping the circuit breaker right after I connect the tool to the battery.
This serves to:
1) ensure you cannot accidentally apply power to anything
2) prove that you have a good ground connection to the battery.
Old thread I stumbled across reading tonight. Just want to add for the pcm power probe now has what they call the "5 volt reference adapter" . Very handy adapter! Only good for certain models of power probe so read the fine print.
I grabbed one of those off the tool truck a few months back. Makes checking the signal circuit quick and easy. I haven't tried it on anything that's missing the 5v ref yet though.
Thank you for sharing this Dtnel. After reading your post I found a place selling them on eBay and my 5v adaptor arrived today. Hooked it up to a spare battery and measured the voltage at the tip with a DMM and the adaptor produced exactly 5.00v on my PPIV. Who knows when I'll need it, but I have it. Signed -Tool Addict. "Hi, my name is Herv and I'm a toolaholic."
