1316 code
Logistics Pro
Joined: Jun 2005
Posts: 4,243
Likes: 16
From: AZ
I have for P1316 possible causes (this is verbatim from the PC/ED diagnostics book):
Possible causes:
- injector(s) or circuit(s)
- Open or shorted IDM enable circuit
- Open / short EF circuit
- Open / short FDCS circuit
- IDM relay
- IDM powering circuits
- IDM
- PCM
Perform KOEO On-Demand Self Test
- Are IDM or any other codes stored?
Possible causes:
- injector(s) or circuit(s)
- Open or shorted IDM enable circuit
- Open / short EF circuit
- Open / short FDCS circuit
- IDM relay
- IDM powering circuits
- IDM
- PCM
Perform KOEO On-Demand Self Test
- Are IDM or any other codes stored?
Post Fiend
Joined: Sep 2003
Posts: 6,096
Likes: 27
From: Mesa AZ
P1316 means your IDM has some issues to report. You need to scan the truck and run some diagnostic tests to retrieve more detailed info.
New User
Joined: Feb 2007
Posts: 6
Likes: 0
Just went through this. SES light came on, noticed a slight miss (not much) and started researching. After ohm testing the UVCH harness on the pass side, discovered excessive resistence on inject#5 and #7. Had a local shop diagnose and discovered 1316, ran an injector buzz test and confirmed that #5 had issues. At this point, there is only one thing to do...remove the pass valve cover. Discovered the UVCH had backed out just a bit. I could have re-inserted and performed a .50 mod, but the harness was so brittle it broke in my hand. Ordered a gasket and harness from Riff-Raff. The harness, while OE, was not an upgraded harness. Decided to try the .50 mod on the new harness and broke that new harness tab as well. This is a poor design on the harness and any mechanic with some PSD experience will say that a 1316 code almost always means a slipped harness. I ended up using zip ties on the harness. Truck runs great now. My advise is to ohm test the gasket on each side and try to determine which side has the problem, then remove the valve cover and take a look. The ohm test is a PITA, so if you have access to a code reader with a buzz test, go that route. Good luck.
Post Fiend
Joined: Sep 2003
Posts: 6,096
Likes: 27
From: Mesa AZ
Just went through this. SES light came on, noticed a slight miss (not much) and started researching. After ohm testing the UVCH harness on the pass side, discovered excessive resistence on inject#5 and #7. Had a local shop diagnose and discovered 1316, ran an injector buzz test and confirmed that #5 had issues. At this point, there is only one thing to do...remove the pass valve cover. Discovered the UVCH had backed out just a bit. I could have re-inserted and performed a .50 mod, but the harness was so brittle it broke in my hand. Ordered a gasket and harness from Riff-Raff. The harness, while OE, was not an upgraded harness. Decided to try the .50 mod on the new harness and broke that new harness tab as well. This is a poor design on the harness and any mechanic with some PSD experience will say that a 1316 code almost always means a slipped harness. I ended up using zip ties on the harness. Truck runs great now. My advise is to ohm test the gasket on each side and try to determine which side has the problem, then remove the valve cover and take a look. The ohm test is a PITA, so if you have access to a code reader with a buzz test, go that route. Good luck.
Are you saying the new OE harness from Riffraff was not the revised part with the two little nubs under the retaining tab?
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New User
Joined: Feb 2007
Posts: 6
Likes: 0
The harness did have the two little tabs that locked from underneath. My old harness had those same tabs, but still pulled out. Those tabs wore out and I expected that a modified harness would have something different, perhaps tabs on the side. I thought the purpose of the .50 mod was to keep those tabs locked into place. Did the pre-2003 harnesses not have the tabs at all?
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Post Fiend
Joined: Sep 2003
Posts: 6,096
Likes: 27
From: Mesa AZ
The harness did have the two little tabs that locked from underneath. My old harness had those same tabs, but still pulled out. Those tabs wore out and I expected that a modified harness would have something different, perhaps tabs on the side. I thought the purpose of the .50 mod was to keep those tabs locked into place. Did the pre-2003 harnesses not have the tabs at all?
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