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-   6.0L Power Stroke Diesel (https://www.ford-trucks.com/forums/forum107/)
-   -   PCM testing (https://www.ford-trucks.com/forums/1508429-pcm-testing.html)

sinapu 09-19-2017 12:48 PM

PCM testing
 
https://cimg5.ibsrv.net/gimg/www.for...29f59b3fd3.jpg
https://cimg7.ibsrv.net/gimg/www.for...72b0656154.jpg
So, I decided to jump in today with both feet.. after checking out the VGT connection, through the doghouse I accessed the PCM and the middle connector, pins 10 and 11 . I used a test light with a good ground and a mirror to test for power at each pin, unfortunately there's no voltage from each one. It runs fine, just has no turbo boost. Can anyone verify that I should be seeing voltage with the key on engine off senerio?

npccpartsman 09-19-2017 01:35 PM

Not sure why you'd even mess with that. Have you code scanned the truck? Have you checked for boost leaks at all the CAC and y-pipe joints?

sinapu 09-19-2017 01:53 PM

Yes, I've been retesting this issue for months and had no voltage at the VGT plug, so I went back to the PCM where the voltage comes from.

I've been getting the P2262 code for months, and it has very little low end power.

Thanks for your reply

npccpartsman 09-19-2017 04:16 PM

P2262: MAP hose, MAP sensor, CAC system leaks, Intake leaks, EP
sensor, exhaust restriction.

Have you checked the MAP sensor hose nipple in the intake for an obstruction? That's the first place to start. If the map sensor can't read boost pressure you won't get the PCM to command any. Also, replace the MAP sensor with a known good one (borrow one from any 6.0 or 7.3) and see if that helps. Also, have you checked the EP sensor tube for a restriction or plugging? Same as with the MAP sensor. Do you have something to read boost pressure with besides the dash gauge?

sinapu 09-19-2017 04:31 PM


If the map sensor can't read boost pressure you won't get the PCM to command any.
Thank you so much for sharing that simple sentence, it's taken me almost a year to understand that fact. Not that I'm anything more than a forum/ YouTube mechanic. That makes total sense now.
I have checked the long tube on the left side of the doghouse, many months ago. Took me hours to screw the damn thing back in.. I do have the Forscan app on my phone which seems to have great reviews so far. . That's how I've been reading the codes and setting up different gauges. Think of mounting an i-pad on the dash and have it there permanently. I'll let you know what I find.

Thanks again

Yahiko 09-19-2017 08:56 PM

One thing you don't want to do is shove the meter probe tip into the connector.
You always go from the back side of the plug or you run the risk of stretching the
pin sockets. The technique is called Back Probing.

sinapu 09-21-2017 05:42 AM


Originally Posted by Yahiko (Post 17474123)
One thing you don't want to do is shove the meter probe tip into the connector.
You always go from the back side of the plug or you run the risk of stretching the
pin sockets. The technique is called Back Probing.

After you told me about this last week, it's the only way I test wires now. Thanks!

sinapu 09-21-2017 05:47 AM

So yesterday, everything checked out with the MAP sensor but I was looking around at a few things while I had it apart. Does anyone know what this plug goes to?https://cimg6.ibsrv.net/gimg/www.for...eafdb9e65d.jpg

npccpartsman 09-21-2017 05:50 AM


Originally Posted by sinapu (Post 17476945)
So yesterday, everything checked out with the MAP sensor but I was looking around at a few things while I had it apart. Does anyone know what this plug goes to?https://cimg6.ibsrv.net/gimg/www.for...eafdb9e65d.jpg

Glowplugs. Green one plugs into GPM

sinapu 09-21-2017 07:23 AM

That's actually pretty good because I don't have any problem with the glow plugs.
I have voltage to the MAP and the tube is clear and looks normal. I looked back at the sensor PSI historically and see that it hasn't been much higher than the 14.6 it is normally at sea level. I'm going to put it all back together and take some new readings today. Thanks for your input

sinapu 09-21-2017 07:30 PM

I put it all back together today and took a drive, not much has changed yet but I took some new screenshots going down the highway at 70 , just for reference. I do have a lot more to choose from but chose ones I thought to be applicable. Maybe this will tell me where I need to go next..https://cimg0.ibsrv.net/gimg/www.for...3bc5d6ffc5.png
https://cimg3.ibsrv.net/gimg/www.for...2bda112fc8.png

DarkStarMedia 09-23-2017 04:46 AM

If that is running down the highway I would say you might have maf issue (not sure if it matters or that I am correct) and possibly a stuck turbo. I assume you have checked that there is continuity between the vgt connector and the PCM connector?

I am just guessing here.... I am sure someone else will chime in.

Richard

sinapu 09-23-2017 09:37 AM

https://cimg9.ibsrv.net/gimg/www.for...a41bf8255a.png
https://cimg0.ibsrv.net/gimg/www.for...ba7426a274.png
Good morning,

I made a bit of headway by changing out the MAP sensor this morning and took it for a ride. Has a lot more power!
I've read in a few different places that the baro pressure and Map pressure need to be within a couple of lbs of each other, which is not the case.
Also still getting a couple of codes, but not the dreaded p2262 anymore, thanks!

FiznUKa 09-23-2017 09:57 AM

MAP,BARO and EBP should all read with in .5 psi of each other. What year make and model of vehicle do you have? It helps if you fill out your signature line with what you have and what's been upgraded

sinapu 09-23-2017 12:23 PM

Any thoughts on where to start troubleshooting?


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