So i have 11.89v on the blue and white wire at the cvsv, but no voltage at the ecu on the grn and red wire/pin 19 on connector E.

 

So i back probed pin 19 with the red lead, then used the black lead and put it to a bolt i seen to the left of the ecu, like right at the front bottom left of the console. Jus in case that wasnt a good ground i went to bolt on the door hinge. Couldnt really see any where else to get a ground connection.

Now that i think of it, if the green and red wire is a ground, shouldn't i have put one of the leads to power? Should i have back probed a power wire to the ecu or did i test properly?

 

As mentioned in the previous post; if the car is not running, the enabling conditions are not set, so the PCM/ECM does not send a ground signal. In the previous test, the multi-meter red lead is touching pin 19 of the PCM/ECM.

 

Now to move on to another test.

With the 2P connector to the canister vent shut valve (CVSV) connected.

Turn the ignition switch to ON (II).

Back-probe to measure the voltage at terminal no. 1 (Lt Grn/Red wire). Multi-meter red lead touching terminal no. 1 and black lead touching body ground.

What is the voltage measurement?

 

Ya that's what i figured. Just figured id double check cause im horrible with electrical diag lol.

So testing for voltage at the ECU and not having any voltage there, what does that conclude? Why were we checking for voltage there? Looking for a short?

I keep forgetting to mention, i do have a power probe 3 so that could make things easier. I just kept forgetting to mention it because i just recently got it, havent used it yet, and usually leave it at work. I should have it with me from here on until i get this issue squared away. I will leave it in my car and only take it out if i need it at work but hopefully remember to bring it home if i take it out at work. Im not very familiar with it since i havent used it yet, just figured id mention it in case it will make testing easier now that i should have it with me from here on. Its always nice to get some practice with the dvom tho since im not very proficient with that yet either lol. Will help me understand electrical diag a little better using the dvom incase there are times i encounter an electrical issue and dont have the pp3 kit on hand.

The pp3 kit that i got is the master kit that has the transmitter and receiver to find short and open circuits. Yup....im an idiot and def should have mentioned that i have these tools lol.

 

ok cool. Dinner just finished cooking so im going to sit down and eat. I will do this test tomorrow after work weather permitting since its too dark out to do anything further tonight. Thank you so much for all your help and advice. With your knowledge n me finally pulling my head out of my ***, we should be able to get this squared away really soon. I really appreciate your help. Sorry for me being an dumbass lol

 

Oh no ok i get it now.

The blue wire will put power through the coil while it isnt running, so if i dont have voltage at the ecu then its not gettin back to the ecu so either the vavle isnt lettin it get back to the ecu or the grn red wire isnt lettin it get back. Had to go back and read you other post a couple times before it sunk in lol. Again...sorry for being a dumbass haha.

 

Ok so i back probed the grn/red wire at the cvsv. I have 12.11v there. I double checked at pin 19 at the ecu, i have 12.11v there as well. I must not have had a good connection with the piece i stuck in there to probe with yesterday.

So now im really confused. I got 12v going to the cvsv, got 12v coming out of the cvsv, even got 12v at the ecu, and the cvsv ohms out in spec. So now what? What could it possibly be now?

 

With the key ON, same state where you get 12v everywhere...

Backprobe the green/red wire, either at the ECU or at the vent-shut valve.

Instead of using a meter, touch that wire to ground. This should cause the valve to open & you'll hear the click (best if you're at the valve itself). Electrically it's just the same as if the ECU commands the valve to open.

Or you could unplug the valve's wiring plug, and just provide 12v power to the valve.

Here's what I'm thinking...
Maybe the valve itself is physically stuck, corroded or something. If the valve isn't physically working, the ECU might see the electrical behavior is incorrect and set the code.

 

The results indicate it is likely a faulty vent shut valve.

DTC P0498 is EVAP Canister Vent Shut Valve Circuit Low Voltage. When the car is running, the evap monitor enable conditions would be set; so, the PCM sends a ground signal.

If the return signal is "OFF" when the powertrain control module (PCM) outputs the "ON" signal to the EVAP canister vent shut valve, the PCM detects a malfunction and stores a DTC.