Intermittent check engine light, UVCH? CPS?
Cargo Master
Joined: May 2010
Posts: 3,047
Likes: 10
From: Snohomish, WA
If the connector is off it doesn't matter key on or off. The uvch is isolated once you disconnect the harness. If you are checking it from the outer connector you are only verifying the glow plug resistance and the resistance to the injector coils. If you see something abnormal between injectors or glow plugs you can isolate it down to that wire or component.
Cargo Master
Joined: May 2010
Posts: 3,047
Likes: 10
From: Snohomish, WA
You can, but you will be getting the combined ohms of the wire and the components attached to them. If you get similar readings across the eight injectors, you probably are ok. If you read different readings on the passenger side than the drivers side, you can try to determine which one is wrong. It will more than likely be obvious.
Understanding what you are reading is the resistance in the parts or the system. When you measure resistance in the UVCH wires you are getting the best reading on the harness as the only thing you are checking is the actual wire. When taking resistance readings you want to keep it as simple as you can. If you have to you can read the entire system, you just need to understand the resistance will most likely be higher and you may not see the problem unless you know the resistance before hand, which is hard to know.
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Thread Ender
Joined: Dec 2010
Posts: 1,296
Likes: 8
From: SC
Well I took the truck to the dealer to have the recalls done. I decided to bite the bullet and have them do a diagnostic check too. As suspected, codes P1316 and P1273 came back.
This is what is printed, verbatim:
ENGINE FAULT CODES P1273 CYL3 OPEN HIGH TO LOW P1316 IDM CODES. OHMED UNDER V/COVER HARNESS, CHECKED OK. THEN CHECKED HARNESS TO IDM. THIS INDICATED A POSSIBLE INTERNAL IDM FAILURE. CEL NOT ON NOW, BUT MAY RETURN IN FUTURE.
So, what do yall think? Cylinder 3 is on the passenger side, right? Is the IDM bad?
By the way, the CEL is on and off again, like before.
This is what is printed, verbatim:
ENGINE FAULT CODES P1273 CYL3 OPEN HIGH TO LOW P1316 IDM CODES. OHMED UNDER V/COVER HARNESS, CHECKED OK. THEN CHECKED HARNESS TO IDM. THIS INDICATED A POSSIBLE INTERNAL IDM FAILURE. CEL NOT ON NOW, BUT MAY RETURN IN FUTURE.
So, what do yall think? Cylinder 3 is on the passenger side, right? Is the IDM bad?
By the way, the CEL is on and off again, like before.
Post Fiend
Joined: Nov 2007
Posts: 9,549
Likes: 14
From: Payson, AZ
Before replacing the IDM I would swap solenoids on #3 and #1 and see if you get a P1271 or another 1273. If you get a 1271 then it is a bad solenoid. If you get another 1273 then check the wiring all the way back to the IDM including separating and cleaning the 42 pin connector and the IDM connector.
If it hasn't been mentioned or you haven't done so make sure the harness on either side of the 42 pin connector is not chafing on anything. The CEL going on and off could be the sign of an intermitent short.
If it hasn't been mentioned or you haven't done so make sure the harness on either side of the 42 pin connector is not chafing on anything. The CEL going on and off could be the sign of an intermitent short.
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Thread Ender
Joined: Dec 2010
Posts: 1,296
Likes: 8
From: SC
Before replacing the IDM I would swap solenoids on #3 and #1 and see if you get a P1271 or another 1273. If you get a 1271 then it is a bad solenoid. If you get another 1273 then check the wiring all the way back to the IDM including separating and cleaning the 42 pin connector and the IDM connector.
If it hasn't been mentioned or you haven't done so make sure the harness on either side of the 42 pin connector is not chafing on anything. The CEL going on and off could be the sign of an intermitent short.
If it hasn't been mentioned or you haven't done so make sure the harness on either side of the 42 pin connector is not chafing on anything. The CEL going on and off could be the sign of an intermitent short.
So I guess the harness goes from the IDM, splits up somehwere then to each valve cover? Where/what is the 42 pin connector?
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Thread Ender
Joined: Dec 2010
Posts: 1,296
Likes: 8
From: SC
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Postmaster
Joined: Dec 2008
Posts: 3,340
Likes: 2
You could pull the valve cover on that side and observe the injector oil discharge. Here is a you tube video that shows checking it: FORD 7.3L DIESEL #8 FUEL INJECTOR - YouTube
If you see that one is not discharging oil the same try swapping the solenoid. You could also check the armature plate clearance: http://www.dieselpro.ca/Poppet%20Valve.pdf
BigAl had a issue with the armature plate clearance recently and was causing a high to low side open code. Here is his thread on the issue: https://www.ford-trucks.com/forums/1...ing-badly.html
If you see that one is not discharging oil the same try swapping the solenoid. You could also check the armature plate clearance: http://www.dieselpro.ca/Poppet%20Valve.pdf
BigAl had a issue with the armature plate clearance recently and was causing a high to low side open code. Here is his thread on the issue: https://www.ford-trucks.com/forums/1...ing-badly.html
Thread Starter
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Thread Ender
Joined: Dec 2010
Posts: 1,296
Likes: 8
From: SC
Before replacing the IDM I would swap solenoids on #3 and #1 and see if you get a P1271 or another 1273. If you get a 1271 then it is a bad solenoid. If you get another 1273 then check the wiring all the way back to the IDM including separating and cleaning the 42 pin connector and the IDM connector.
If it hasn't been mentioned or you haven't done so make sure the harness on either side of the 42 pin connector is not chafing on anything. The CEL going on and off could be the sign of an intermitent short.
If it hasn't been mentioned or you haven't done so make sure the harness on either side of the 42 pin connector is not chafing on anything. The CEL going on and off could be the sign of an intermitent short.
Thread Starter
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Thread Ender
Joined: Dec 2010
Posts: 1,296
Likes: 8
From: SC
So I started testing the IDM per ShakeNBakes instructions.
Test 1 ( All circuits should be between 2.8-3.6)
Left Bank Power feed to Inj. #2 Ground = 5.2 ohms
""""""""""""""""""""""""""""""" #4 Grd = 3.8 ohms
""""""""""""""""""""""""""""""" #6 "" = 3.8 ohms
""""""""""""""""""""""""""""""" #8 "" =5.0
Right Bank Power feed to Inj. #1 Ground = 4.0 ohms
"""""""""""""""""""""""""""""""" #3 """" = 3.9 ohms
"""""""""""""""""""""""""""""""" #5 """""""" = 3.9
""""""""""""""""""""""""""""""""" #7 """""""" = 4.0
Test 2
Bank power feeds to IDM Ground showed Open
Test 3
Bank power feeds to Injector Ground Shield showed open.
So I am obviously out of range. Also, when pulling the harness from the IDM, I can see what looks like moisture on the end of the plug, around the terminals, and also on the inside of the IDM around the pins. ON the pins in the IDM and IN the terminals on the harness I can see some cruddy looking creamy substance, is this dielectric grease or something?
What does the high resistance indicate exactly?
Test 1 ( All circuits should be between 2.8-3.6)
Left Bank Power feed to Inj. #2 Ground = 5.2 ohms
""""""""""""""""""""""""""""""" #4 Grd = 3.8 ohms
""""""""""""""""""""""""""""""" #6 "" = 3.8 ohms
""""""""""""""""""""""""""""""" #8 "" =5.0
Right Bank Power feed to Inj. #1 Ground = 4.0 ohms
"""""""""""""""""""""""""""""""" #3 """" = 3.9 ohms
"""""""""""""""""""""""""""""""" #5 """""""" = 3.9
""""""""""""""""""""""""""""""""" #7 """""""" = 4.0
Test 2
Bank power feeds to IDM Ground showed Open
Test 3
Bank power feeds to Injector Ground Shield showed open.
So I am obviously out of range. Also, when pulling the harness from the IDM, I can see what looks like moisture on the end of the plug, around the terminals, and also on the inside of the IDM around the pins. ON the pins in the IDM and IN the terminals on the harness I can see some cruddy looking creamy substance, is this dielectric grease or something?
What does the high resistance indicate exactly?
Post Fiend
Joined: Sep 2003
Posts: 6,096
Likes: 26
From: Mesa AZ
Injector solenoid resistance is high almost across the board but that could be due to the junk in the connector. Sounds like there might be water in the IDM. Remove it and see if any pours out. Might want to open the case and look for any water damage. If you see any then it will need to be replaced.
If the inside looks well and dry, then get yourself a spray can of electrical parts cleaner and some tiny pipe cleaning brushes. You will need to clean the connector with the spray cleaner to get all that junk out of there. Usually that stuff is all dried up and flaky but since you have water present it probably turned to mush.
Clean it up, and see if that does the trick. You can use some new die-electric grease to attempt to seal it back up again. From what I've read there is grease designed just for the perimeter sealing boot and another type that can simply be smeared all over the connector....I use the second type and haven't had any issues. Just make sure you read the instructions for the type of DE grease that you are using and you should be fine.
Good luck...
If the inside looks well and dry, then get yourself a spray can of electrical parts cleaner and some tiny pipe cleaning brushes. You will need to clean the connector with the spray cleaner to get all that junk out of there. Usually that stuff is all dried up and flaky but since you have water present it probably turned to mush.
Clean it up, and see if that does the trick. You can use some new die-electric grease to attempt to seal it back up again. From what I've read there is grease designed just for the perimeter sealing boot and another type that can simply be smeared all over the connector....I use the second type and haven't had any issues. Just make sure you read the instructions for the type of DE grease that you are using and you should be fine.
Good luck...
Post Fiend
Joined: Sep 2003
Posts: 6,096
Likes: 26
From: Mesa AZ
. Not sure how much the grease costs though...I got my stuff for no charge. 