DTC codes P1271, P1272, P1277, P1273 and P1274?

1996 FORD F-350
250,000 MILES • 7.3L • V8 • TURBO • 2WD • AUTOMATIC
Avatar
PROMIKE94
  • MEMBER
  • 10 POSTS
I just replaced the wiring harness with a different wiring harness and IDM and now I’m getting these codes when I do an injector test. The truck will not start anymore, and I also replaced the driver's side valve cover gasket before all of this. Originally, I was having an issue with the oil pressure I replaced the ipr valve and that didn’t fix it. I’m not sure what happened that now I’m getting all of these codes at once and it’s not just one side of the engine, I guess.
Sep 15, 2024 at 6:35 PM
Advertisement
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
Yep, these are wiring harness codes, is everything connected? If so, I would get another harness.

P1271 - Cylinder #1 High to Low Side Open
P1272 - Cylinder #2 High to Low Side Open
P1277 - Cylinder #7 High to Low Side Open
P1273 - Cylinder #3 High to Low Side Open
P1274 - Cylinder #4 High to Low Side Open

Let me know if you need anything else, or upload images so I can see what's going on.
Sep 16, 2024 at 10:52 AM
Avatar
PROMIKE94
  • MEMBER
  • 10 POSTS
So I’m not sure if this has to do with anything but my glow plug relay only has power on one big terminal and the other doesn’t. I was doing research, and it says both should have power when the key is on. I’m not sure if the wires are on correctly do you have a wire diagram for this? Thank you
Sep 16, 2024 at 5:24 PM
Advertisement
Avatar
PROMIKE94
  • MEMBER
  • 10 POSTS
And I put my old harness back in and I’m having the same out come with the injectors. I’m pretty sure the wires on the for from the other harness were on different so could I have burnt out this relay?
Sep 16, 2024 at 5:26 PM
Avatar
PROMIKE94
  • MEMBER
  • 10 POSTS
GPR not for**
Sep 16, 2024 at 6:02 PM
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
Yep, there should be power at two of the terminals for the glow plug relay, here are the wiring diagrams for the engine and glow plug relay so you can see how the system works and which wires to test.

This guide should help you as well:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the images (below). Let us know what you find.
Images (Click to enlarge)
Attached Media
Attached Media
Attached Media
Attached Media
Attached Media
Attached Media
Sep 17, 2024 at 8:59 AM
Avatar
PROMIKE94
  • MEMBER
  • 10 POSTS
So, I got that all sorted the test now passes but I have no fuel pressure at the valve on the fuel bowl. I’m not sure where to start from here.
Sep 19, 2024 at 6:58 AM
Avatar
PROMIKE94
  • MEMBER
  • 10 POSTS
Okay, I got it started. So, it starts fine then 10 seconds later the check engine light will come on and idle very rough. This was my main problem. And when I scan for DTCs nothing shows up besides when I run tests on it.
Sep 19, 2024 at 7:44 AM
Avatar
PROMIKE94
  • MEMBER
  • 10 POSTS
I replaced the IPR CPS and ICP sensor. When I ran the tests p1284 and p1211 pop up.
Sep 19, 2024 at 7:47 AM
Avatar
STRAILER
  • CERTIFIED EXPERT
  • 53,854 POSTS
Glad you could get it fixed, thanks for letting us know. Please use 2CarPros anytime we are here to help.

Sorry, we only handle one problem per thread, please post your new question here, you must be logged in.

https://www.2carpros.com/questions/new

Cheers, Ken
Sep 19, 2024 at 10:15 AM