Hey all,

I have now put in my 4 hours of researching forums. I can't seem to figure this out!?

I have a check engine light...

Codes:

p1316 IDM DTC's are stored
p1670 electronic feedback not detected

Are these two codes related? Is the problem the p1670 and that is triggering the p1316?

I am familiar with the not so good UVCH which in my case could very well be faulty. I have done the "wiggle" test. nothin'. I am not sure how to test the pins from the IDM to the PCM... which was suggested in another post...

ANy thoughts?!? Thx guys check engine light making truck run like crap... it was sitting for about 6 months but this is a re occurring problem.

Before I buy UVCH and a IDM could it be the PCM?

 

So what year/motor do you have? Know that then we can help better?

 

oops... ya sorry about that!

its a F-250 7.3 year 2000...

pretty essential info!

 

Possibly. P1316 means there are codes stored in the IDM that should be retrieved. You will need a quality scan tool such as AE, SnapOn, Ford IDS etc to retrieve those codes.

P1670 electronic feedback not detected means one of the modules or sensors isn't communicating with the PCM. It's a vague code that isn't very helpful by itself.

Very unlikely it's the PCM. IDM is more probable but still quite unlikely.
UVCH is the most probable. I will attach a tech bulletin that shows how to test from the IDM connector itself. Accessing the IDM is a bit of work since it's buried in the fender so you may want to test at the main engine harness connector first. If so, here is a photo that shows some of the pinout cross references.

 

Thanks a bunch for that info!

I have taken the IDM off and cleaned the pins... I replaced it about 5 years ago with a brand new one from Ford. I remember the cost being atound 1,000!! A stupid mistake!

Wow that pdf is exactly what I needed! I could not understand how to test all these plugs that I was reading about on other forums but that pdf really puts it all together really nicely! Thanks so much!

Should I ground the multi meter to the battery ground for ohm-ing?

 

So I think I understand most of the test.. I just don't know where to put the mulit meter probes exactly... I have not much experience with multi- meters... but I own a decent one!

Do I ground the multi meter to "P" or "D" in the picture above and then use the positive side of the multi meter on 1,2,3... to 8?

 

To test resistance, set your meter to OHMS.
Place one lead in the P+ and park it there while you use the other lead to probe 1,3,5 & 7 (one at a time). That will give you a resistance reading for the injector solenoids for that bank.

Repeat for D+ (lead one) and 2,4,6 & 8 (lead two).

Tests 2 and 3 should really be performed at the IDM connector itself since that's a measure of the entire wiring path. If you wish to run those tests at the 42 pin connector, then you'll need to know which pin is ground and which is the Shield. I might be able to figure that out by looking at the wiring diagrams on file.....if so, I'll post a revised photo showing those locations.

 

right on. I have the wheel well cover still off so I will do it when the sun comes up tomorrow...

I will run the test from the IDM to complete the whole wire path.

Thanks so much for this I will post my results soon!

 

Hey there all,

So I just did the ohm test for my injector resistance test.

I pulled the IDM plug from the IDM module and tested the female plug there under the drivers side wheel well.

All injectors tested 3.3 ohms resistance, except #5

Number 5 injector showed open circuit. Any idea what this means? Does this suggest that it is unplugged? Or the solenoid on the injector is bad?

I guess that the UVCH could be bad.. a common problem... I guess its time to tare into it! I will be in touch and welcoming thoughts on what this could be!!

Thanks again!!!

 

so i just tested the UVCH and everthing seemed to be fine.. it was very difficult on the passenger side with out a pig tail!! But I think that the injectors all ohm out good on the UVCH. I am going to test again to make sure...

Then I took the main plug on the drivers side apart and plugged the UVCH back in again to test from there..

Same results. #5 injector is coming up on my volt meter as 0.L which I am assuming is open circuit?

So if #5 injector has normal resistance (pass an ohm test) that means that there is a disconnected wire in between the main injector plug harness (drivers side main plug) and the UVCH female connector...

Is that right?
Is there a way to test the continuity of that #5 wire? I am not sure how to do that..
I am still unsure about the UVCH.. I will check it again...

 

Did you remove the passenger side valve cover and inspect the UVCH?

A good method is to test at the IDM connector, which you already did and #5 tests open (faulty). Keep in mind you are only checking the electrical circuit at this point....

Next thing to do is check resistance at the main engine harness connector (at left side valve cover). Use the photo posted earlier for reference....place one test lead on P+ and the other on #5. If the circuit measures good then your problem is somewhere between the IDM and engine harness connector. If the circuit is still open, then remove the right side valve cover and look for a loose UVCH.

If that looks fine, then verify that #5 is connected...it is the third injector from the front.

If the wiring looks good, then unplug the UVCH and test the hot and ground side. Start with the hot side first. place one lead on the center pin of the valve cover gasket plug where the UVCH normally plugs in and the other lead on P+ pin on the engine side of the main engine harness connector. You should get a reading....an Open is bad. If OK, then check the signal (ground) side. Place one lead on the 6th pin from the front on the valve cover gasket connector and the other lead on #5 on the main engine harness connector. Again, you should get some resistance and an Open circuit is bad.

If all that tests good, then check the UVCH. Place one lead on the center terminal and the other lead on the 6th terminal (counting from the front of the vehicle ). If that tests open the unplug the injector and test the solenoid itself. There are only two pins on the solenoid so place a test lead on each pin and see if you get a reading.

 

Thanks for the great advice. I will do the later test tomorrow morning for sure!!

The problem is that at the male side of the UVCH I tested the #5 injector and instead if reading an open circuit it read really high resistance. Hmmm.

It was over 110 ohms!! And I checked to make sure that it wasn't .110 ohms. There is much resistance here.

Could that mean that there was a potential short in the wire that lead to a blown solenoid? This is confusing to me!

Regardless, I will take the valve cover off in the morning and test the UVCH and the solenoid of #5.

It's strange to me that #5 would read "O.L " at the IDM and at the male side of the UVCH read 110. Ohms high resistance!? Any sense there!?

 

Both sides of the UVCH is female. Both sides of the valve cover gasket is male. Where exactly were you taking your reading from? The ONLY way to access the UVCH is by removing the valve cover.

UVCH stands for Under Valve Cover Harness.

 

I was testing the male side out side of the valve cover, with the valve covers on. I was using the method in the thread where the guy has the video of testing the glow plugs on this type of engine. This one:

Terminal positions=G G I I C I I G G
G=Glow Plug
I=Injector +
C=Injector -
( I think that you made a correction here to the injector not being + but the "C" is +...

Pretty weird that it would test high resistance at the valve cover and open circuit at the IDM, huh?!?

I am about to take the pass side valve cover off and test the gasket.. I will post results soon!

Thanks so much for the guidance!! Really appreciate it!!

 

Correct, that pin-out chart is not accurate. The center pin is injector power. For Bank 1, right side (passenger side in North America) the pin out chart looks like this:

1. Glow Plug + cyl 1
2. Glow Plug + cyl 3
3. Injector signal (ground) cyl 1
4. Injector signal (ground) cyl 3
5. Injector power
6. Injector signal (ground) cyl 5
7. Injector signal (ground) cyl 7
8. Glow Plug + cyl 5
9. Glow Plug + cyl 7

It is very difficult to test the external side of the valve cover gasket unless you have a pigtail harness. I would remove the valve cover gasket and trouble shoot some more. You might find a loose connection, damaged harness or faulty solenoid. Sometimes one or more of the pins/terminals can burn or arc and cause an intermittent fault. Usually the center pin is the culprit but it could also happen on the glow plug side as well. Here is a photo showing what a burned center pin looks like. I'll also attach a photo that shows what the 50 cent mod looks like in case you have the OE type harness still. (The replacement Ford/IH UVCH has molded tabs that do not need the 50 cent mod...)

Good luck!