Keith Browning Posted August 1, 2015 Share Posted August 1, 2015 I had several tough ones end up in my bay this week but this one was a challenge. A 2011 6.7L that had a surging, low idle, stalling and a check engine light. I had quite a few DTC's in the system half of which were network codes. I recorded them all and erased them to start out fresh since the codes were "all over the place." I restarted the diagnosis with a freshly set P0093. It gets interesting from here. Retrieved CMDTCs, KOER and KOER self tests - BOTH tests return "Test Aborted" and do not complete. Performed Pinpoint tests M-1,2,3,5,6,9,12,15,17 Tests were extremely difficult to complete with the erratic idle and stalling. Testing at that point was inconclusive. I performed a wiggle test and the engine ran properly after moving poking around the FPR and tapping on the fuel rail. I disconnected the FPR and the KOEO self test completed with an in demand DTC of P0090. I reconnect the FRP and the self test does not complete. I get the same result when repeating this step. What would you think at that point? Yeah, I thought so. I replaced the FPR. No change. So instead of falling into that trap of diving deeper I decided to return to the beginning. Looking at ALL of the codes I originally retrieved. I did read SSM 44681 - and inspected fuse 33. It was good and I reinserted it. The truck ran ok for a few minutes and then started acting up again. 2011-2015 F-Super Duty - 6.7L Diesel - Runs Rough or Cranks no Start With MIL On And Diagnostic Trouble Codes (DTC) P0087, P0088, P0089, P0093,P228F, P2291Some 2011-2015 F-Super Duty 6.7L diesel equipped vehicles may exhibit an illuminated MIL and DTC P0087,P0088,P0089,P0093, P228F or P2291 associated with a rough idle or crank no start condition. If this condition is present, inspect fuse 33 in the Battery Junction Box (BJB) for an open condition. Use a Digital Volt/Ohm Meter (DVOM) to check the voltage on each pin of the fuse. If there is a voltage difference of more than .5V the fuse is open. Replace the fuse and re-evaluate the concern. If the fuse is not open or any DTC's other than the above are present, follow normal PC/ED diagnostics.EFFECTIVE DATE: 25-AUGUST-2014 I looked at the EVTM and determined that fuse 33 feeds three circuits going into the PCM and labeled VPWR. Time to take another look at that circuit and maybe the fuse. I back probed pins 67, 68 and 69 at the PCM and found that the voltage was erratic - I hit the Smooth button on my Fluke meter and the voltage settled to a little under 8. Long story short I looked at that fuse much closer. Still not blown and I had B+ at both sides of the fuse. BUT. I noticed a black spot on one of the fuse blades. Borrowed a magnifying glass and son of a bitch! Arcing! (terminal fretting for you aficionados) I cleaned the fuse block terminals and replaced the fuse. Cleared the codes and road tested the truck to verify the repair. Just thought I would share one of "those" repairs with y'all. So keep this kind of thing in the back of your mind. Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted August 1, 2015 Share Posted August 1, 2015 Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted August 1, 2015 Author Share Posted August 1, 2015 I saved the fuse cuz' I wanted to take a good picture of but left it at work. I'll snap a picture next week and post it. Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted August 2, 2015 Share Posted August 2, 2015 You can use these for the time being. Quote Link to comment Share on other sites More sharing options...
DieselD Posted August 3, 2015 Share Posted August 3, 2015 I had something similar happen on my 2011 except it was for the DEF system. It was a temp code IIRC. The damn fuse was fretting and took quite a while to track down Quote Link to comment Share on other sites More sharing options...
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