I've got a 1271 code and I can't seem to make it go away.
Code definition is "High side to Low side open Cyl 1"
the truck runs fine, no rough idle, no excessive smoke of any color, just the damn CEL light stays on.
I check the UVCH and all the injectors ohm in at 2.7 ohms. I've already done the updated clips under the covers. I run all the buzz tests and KOEO/ KOER tests and all appears OK. My AE won't do a Cyl contribution test. All the injector data shows all 0.00. I know its not that perfect.
"high to low open", does that mean I've lost a ground? If so where?
Thanks for the help
Barney

 

Don't know Barney, mine is doing the same on #2 but no performence issuse? heres a bump for ya.

 

Thanks Robert, I know Sunday afternoon is not the time to ask tech questions and expect a quick response. Most everyone is out with the family or doing something else.
I'm unsure if the injectors are ground controlled or power controlled. I'm hoping one of the many brothers or sisters on here that are smarter than me will pop in with a answer

Barney

 

Bump ^^^^for you Barney!
What little I know sounds like losing ground,were at I don't know.Not unless a wire is broke inside itself not making full connection.

 

Barney. Here is some test procedures from my Ford Repair DVD. Hope this helps.


NA11 DIAGNOSTIC TROUBLE CODES (DTCs) P1271-P1278
DTCs P1271-P1278 indicate a low side-to-high side open in the circuit between the IDM and the injector. The following table lists the circuits to inspect while performing these pinpoint tests, based on the DTC retrieved during the KOEO On-Demand or Injector Electrical Self Tests.
Note: If all of the DTCs associated with an entire bank are retrieved, the high side circuit is most likely open.



Cyl. DTC Low Side High Side Bank
1 P1271 555 (TN) 1087 (OG) Right
2 P1272 556 (WH) 878 (PK/YE) Left
3 P1273 557 (BN/YE) 1087 (OG) Right
4 P1274 558 (BN/LB) 878 (PK/YE) Left
5 P1275 559 (TN/BK) 1087 (OG) Right
6 P1276 560 (LG/OG) 878 (PK/YE) Left
7 P1277 561 (TN/RD) 1087 (OG) Right
8 P1278 562 (LB) 878 (PK/YE) Left


Disconnect injector valve cover connector.
Install Glow Plug Injector Adapter 014-00935 or equivalent to valve cover gasket.
Measure resistance between the high side and low side on the injector. Refer to injector illustration at beginning of this pinpoint test for correct pin location.
Is the resistance less than 5 ohms?
Yes No
GO to NA13 . GO to NA12 .

NA12 CHECK INJECTOR FOR OPEN CIRCUIT
Remove valve cover.
Disconnect injector connector.
Measure resistance between high side circuit from adapter tool and injector connector.
Measure resistance between low side circuit from adapter tool and injector connector.
Is each resistance less than 5 ohms?
Yes No
INSTALL a new injector. RESTORE vehicle. CLEAR DTCs and RETEST. GO to NA23 .

NA13 CHECK FOR OPEN IN LOW SIDE CIRCUIT
Disconnect IDM harness connector.
Measure resistance on injector low side circuit between valve cover connector and IDM.
Is the resistance less than 5 ohms?
Yes No
GO to NA14 . REPAIR open in low side circuit. RESTORE vehicle. CLEAR DTCs and RETEST.

NA14 CHECK FOR OPEN IN HIGH SIDE CIRCUIT
Measure resistance between suspect injector high side circuit on injector harness connector and IDM connector.
Is the resistance less than 5 ohms?
Yes No
Fault may be intermittent. GO to NA15 . REPAIR open in high side circuit. RESTORE vehicle. CLEAR DTCs and RETEST.

NA15 CHECK FOR OPEN INJECTOR CIRCUIT
Measure resistance between suspect low side and high side circuit at the IDM connector. Refer to injector illustration at beginning of this pinpoint test for pin location.
Grasp the harness close to the suspect injector harness connector. Wiggle and shake harness while working your way back to the IDM.
Do resistance readings ever go above 5 ohms?
Yes No
ISOLATE open in circuit and REPAIR. RESTORE vehicle. CLEAR DTCs and RETEST. INSTALL a new IDM. RESTORE vehicle. CLEAR DTCs and RETEST.

NA23 DETERMINE WHETHER GASKET OR UVC HARNESS HAS FAILED
Disconnect UVC harness from gasket.
Measure resistance across each contact in the gasket.
Is each resistance reading less than 5 ohms?
Yes No
INSTALL a new UVC harness. RESTORE system. CLEAR DTCs and RETEST. INSTALL a new valve cover gasket. RESTORE system. CLEAR DTCs and RETEST.

 

THANKS Roland!!! that's exactly what I needed!! it shows the injectors are ground controlled. And the tests too! man, thanks again. Probably won't get back to it til the weekend but will let everyone know what happens

Barney

 

Please do.... Subscribing.

 

Roland that cd seemsamazing where is it avalible and how much?

 

I bought it, a few years ago, from an ebay seller. It is a Ford published dvd. The seller is no longer listed. IIRC, Clay @ Riffraff Diesel Performance has some repair dvds. I haven't seen one, but it is most likely the same. I'd check with him.

 

If you want you can upload it to me and I can post it

 

I ran all the tests that I could and verified all the harnesses.(thanks again Roland). Everything is good. So it appears I have an internal fault in the IDM. if I had a spare I could install just to confirm my diagnosis that would help but, I don't. so for the time being I'm just going to ignore the CEL. Thanks for everyone help.

Barney

 

I'm having the same issue myself...just with the occasional rough idle and shaking.

Did you ever replace your IDM?

 

Never replaced the IDM. what I did find was a bad solinoid on the injector. I swapped the solinoids between the injector with the code and another injector and the code followed the solinoid. I bought a new one off Ebay and the light went away. the mileage also came back and the idle smoothed up. good luck
Barney

 

That's exactly what I thought it was too! After venturing below the valve covers twice in one month, I haven't been in the mood....I'll give that a shot and see if it clears up my problem.

I may not go through with this given that I'm upgrading to some Singles soon, but it may be worth it...

Is there a particular seller you'd recommend?

 

I am a newbie to the 7.3 I worked on class eights, I also have a 1271 code with a 1219, I have tested everything I can find I started out with a bad harness on the engine replaced that along with the valve cover gasket, I was given the pin outs for the IDM, buy a smart guy on this site, and tested those I need to change the left valve cover gasket for poor connections internally, but the right side resistances are all 3.0 to 2.9 Ohms.
Can someone give me the heads up on doing the R&R of the solenoid, what will I find and are there parts I need before I try it.
Also is there a test set up to test the IDM out put, like a noid?
I do not want to buy an Injector if it is an IDM, or an IDM if it is the Injector.