exmod110 Posted March 4, 2015 Share Posted March 4, 2015 Got an 05 466e with egr the keeps blowing the IDM fuse in the battery box. koeo no problem, start it up and 3-4 sec the fuse blows like clock work. Has Codes 534 idm relay voltage (blown fuse) and 525 idm failure circuit "M" only active when the fuse is open circuit. In the recent month it has flagged all 6 injectors with 421-426 low to high side open or shorted to b+ but no related driveability concerns noted with codes being inactive multiple times.. I can run the koeo injector test, they all pass and the fuse is ok. as are all the other koeo tests. Code 525 tells me to just replace the IDM but im hesitant to drop a $1200 IDM for that... What outside of the IDM will cause this fuse to blow only when running like a bad injector ?? I have rulled out shorts from the battery to the IDM. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted March 6, 2015 Share Posted March 6, 2015 Well I have no experience with this engine or the application but it sounds like you figured it out. As long as you have also ruled out anything else that is on that power circuit. Quote Link to comment Share on other sites More sharing options...
mchan68 Posted March 9, 2015 Share Posted March 9, 2015 I have no experience with this engine either, but it almost sounds like a textbook FICM failure on a 6.0. As in IDM failure. Do you have a spare 'tester' you can plug in to verify this? Or the better question would be if it is plug and play. Quote Link to comment Share on other sites More sharing options...
exmod110 Posted March 9, 2015 Author Share Posted March 9, 2015 Unfortunately no, it is the only one of that vintage. We have ordered a new idm. We cant program it here so it needs to be towed to IH anyway. It looks exactly like a 6.0 ficm. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted March 9, 2015 Share Posted March 9, 2015 Put an amp clamp on the power wires and unplug the IDM, and see if the fuse still overamps, then plug it back in. Look for rubbed harnesses, they are common on this truck, especially near the LR of the engine. There's also a 12 pin connector on the LR of the engine which feeds power/ground to the IDM along with data circuits, it's known well for intermittent opens, I can send you a PDF of the engine schematic if you need it. The IDM relay is in the underhood fuse box, I'm sure you know, if the decal on the lid is missing or unreadable let me know and I'll ID the relay for you. I'd unplug the IDM, unplug the IDM relay and put a jumper wire across it, and an amp clamp on the jumper wire. Yes, visually the IDM is identical to the 6.0 FICM. Too bad you're not closer, I think I have a known good ECM/IDM for this truck....... 1 Quote Link to comment Share on other sites More sharing options...
exmod110 Posted March 9, 2015 Author Share Posted March 9, 2015 The fuse only blows while the engin is running. Koeo its under 4 amps and 35ish running untill it pops. My meter isn't quick enough to pick up the spike. Runs for 3-4 sec and pop. the first place I checked was the relay after the fuse. Quote Link to comment Share on other sites More sharing options...
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