Electrical question

Very curious as to why I might get the same results whether I used E1 or E2?

 

I can roll with the manual for testing purposes.

 

Ha-ha! Listen to me. "I can roll with it" as I search for those lost marbles....

 

I would need to sit down and look to know for sure but your to pin outs on the ECM might be Common

This is so much easier with the vehicle at hand I know what I need to do to test your sensor .

You have read through the first 50 pages of the EWD??It guess some simple info on how to use the EWD I like my Hard Copy but I am getting used to the online version.

Thanks who ever shared this.

 

So I could test something else using e1 & e2 & see if the same thing happens?

 

I think I would prefer a hard copy over the computer. Someone had shared the wiring pdf on my taillight fun filled escapade last year. The only problem is it’s not searchable. When routing around for FSM’s I found this “mark of shame” wiring version, as well as the FSM which is probably an ‘03, but states ‘01. The good thing about these versions is they are searchable. Makes it a little easier. I posted them on the fsm sticky.

 

So I am going to correct that. The mark of shame fsm must be an earlier version because it had the non egr canister like mine. The difference is the wiring colors &/or placement.
Ok - so bottom line for me is that I have a correct wiring manual. It is the actual diagnostic manual that has different wire colors & potential schematics. For instance E2 is br/b in the fsm. My e2 is lg. Other thing though, is, as far as the wiring, I haven’t noticed anything, other than a few notations, as to mt vs at.

 

Look what I found. This is from the '95.5-'97 I use from time to time since it has the same engine. I decided to look & see if it had the same mixed message instructions & results. It does. I haven't investigated further yet.

 

P0450 -
Condition -
(a) or (b) continues (2 trip detection logic)
(a) PTNK < 0.5 V or PTNK > 4.9 V (Within 10 sec. after starting enginu
(b) PTNK < 0.1 V or PTNK > 4.9 V (After 10 sec. after starting engine)

Because I keep finding the two differing test results & this code seems or is related, would it make sense that I could just set up the meter at the ECM, start the truck & see if any of these happen?

 

You said 3 VSV`s had failed just in what way did they fail was it mechanical they just no longer moved.

Electrical the coils just opened and no longer worked to move the valve.

This could point to where the problem is.

 

I guess i’ll put mechanical. It is a one way valve. Open when it’s told to purge. Closed when it’s told not to purge. The test is 1. to check it without voltage = no air flow. Then 2. with voltage (at least 9v) = valve should click open once, even if you leave the leads on the valve, one click. 3. as the voltage (9-12v) is constantly applied. air should flow one way only, canister hose to manifold hose.

Mind you I am gradually learning about the truck, so I did not test the first one until 3? 4? years later (now) of it sitting around & it was stuck closed - no air either way with or without voltage (at least 9v) applied.

The other two had air flowing both ways with voltage (at least 9v).

They all pass the click test.

The one that is on there now passed the tests before being installed.

Once the truck warms up they click(ed) rapidly away. As if non-stop opening & closing, a constant state of purge confusion, while the truck was/is running. & I mean nonstop. This one I have now is quite loud. Not sure why it is, but it’s somewhat helpful in that I can hear it even at higher speeds.

So, electrical? Maybe, only in that I have not checked it through the ECM because everything else checked out & I had not delved into this area until a few? days ago. I can do that today.
If it passes, i’ll stick with mechanical.

Question is why. This is why I am targeting other things that affect the valve’s state.

 

I wish I understood the sensor better. It’s funny trying to apply logic to something you don’t get. I mean .04 seems awful low. Also, no matter how much vacuum it doesn’t change. .04.

Anyway, I did hook it up to the ECM, started the truck & let it run for a good 10? maybe 16 mins. Started at 3.6 v. Dropped a pinch to 3.54, then began a slow, steady climb to 4.96 v. Stayed put for a couple of minutes & then a slow, steady decline finally settling on 4.54 v. Throttling up didn't phase it. The rise in voltage started before the vsv for evap kicked in & when it did, the rise in voltage held steady & kept rising. What this all means as far as the big pic? It does mean though, that the vsv for vps was not told to go to work. Other thing though is that the vps reaching 4.96 is outside one of the parameters for the P0450 I posted earlier - post# 29