jtpfarm Posted September 15, 2022 Share Posted September 15, 2022 (edited) I have a 96 CH613 with an E7-350. I have been having an engine shutdown problem. So far only while idling. It will die like the key is shut off with electronic malfunction light. It's giving me code 6-2. (I've read other topics with this problem but have never seen a solution) Grounds have been cleaned and plug by the pump checked. It generally takes 30 seconds before it will restart. Does anyone have any ideas? Thanks. Edited September 15, 2022 by jtpfarm Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 are you losing fuel prime? due to a loose fitting, or dry rot fuel line, loose connection at the tank outlet hose, and it is sucking air.. when it cuts off, have you pulled the fuel filters to see if the level is too low..? Mack Truck VMACIII 1998 Fault Codes List .. I just found out that my folder with a ton of info is gone off my computer, so I cant look at the 6-2 code flowchart.. Quote Link to comment Share on other sites More sharing options...
jtpfarm Posted September 15, 2022 Author Share Posted September 15, 2022 (edited) It's definitely not a fuel issue. If sits 30 seconds or so it starts right up. (Not crank for 30 seconds) It looks like the code is date line input no signal. I am told this is a Vmac 1 (I know it's not a 3) I only get electronic malfunction, no engine shutdown light when the problem happens. Edited September 15, 2022 by jtpfarm Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 ok,, there are a few ways to tell, if it Vmac 1 or 2.. If when you shut the key, and all electric power goes off instantly.... VMAC1,,, if there is a delay, VMAC 2.. Yes, it is not VMAC 3.. Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 hopefullu you will find the procedure to test the data lines, I beleive they are all white, and not yellow and green like later years.. Quote Link to comment Share on other sites More sharing options...
jtpfarm Posted September 15, 2022 Author Share Posted September 15, 2022 Apparently this is a fairly common problem that no one has posted the answer to. Lol. Looks like it's a vmac 1. Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 yes, that happens too much.. I wish folks would post the solutions.. I guess you have some elec. diag. to do. I have book, but I cant post pics anymore.. jojo Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 Heck there could be a dozen issues, do you lose any other elec functions? I wonder about any relays that are getting hot. Did you inspect the F.I.C. Module? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 I see I sent the wrong link for your truck.. I sent vmac 3... Sorry..jojo Quote Link to comment Share on other sites More sharing options...
jtpfarm Posted September 15, 2022 Author Share Posted September 15, 2022 No other functions lost that I noticed. And so far it will ONLY occur after coming to an idle after any sort of acceleration. For instance, tonight I drove it 3 miles, came in the yard and about 10 seconds after I put it in reverse it died. The other day I started it, drove 500', opened the door and it died before I got to the ground. The truck only has 185,000 original miles on it. I have not inspected the FICM, where is it and what is there to look for? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 It's under the kick panelon the right side. You sure the acc relay isn't loose or failing? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 There should also be a relay on the firewall near the center as well as a ground breaker, it is black and round. It is just grounds. Quote Link to comment Share on other sites More sharing options...
jtpfarm Posted September 15, 2022 Author Share Posted September 15, 2022 You mean the big round relay/solenoid in the glove box? That is new. Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 I thought it was behind the center dash panel. It makes a loud click when you turn the key on.. Quote Link to comment Share on other sites More sharing options...
jtpfarm Posted September 15, 2022 Author Share Posted September 15, 2022 Update, I have discovered if I pull fuse 32 which sends power to the fuel actuator through the shutdown relay, I get a shutdown with the same code. Also noticed the shutdown relay gets very warm. Any ideas? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 loose connections,,,,, short to ground on a power wire( could just be a rubbed through spot) swap the relay with another that is the same and re-test, for it heating up.. jojo Quote Link to comment Share on other sites More sharing options...
jtpfarm Posted September 15, 2022 Author Share Posted September 15, 2022 I swapped the relay and it's maybe not quite as warm. Wiggled and moved everything I can find with no luck replicating the issue. Going to hook a small light to that fuse to see it shuts off next time. 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 can you run the truck in the yard, and duplicate the issue? I really think there is a loose wire, maybe you can tug on the wires on the back side of the suspect socket and see if it pulls out easy... these diags. can really be a B!..H!... jojo Quote Link to comment Share on other sites More sharing options...
jtpfarm Posted September 15, 2022 Author Share Posted September 15, 2022 I've been trying all day to duplicate the problem after having it occur every time we have driven in the past. I've grabbed and pulled/wiggled every wire I can reach. Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 well you may have just improved a weak connection... Hope it stays good.. if you own an I.R. thermometer, use it... you can check temps and compare them to similar components.. Good luck... jojo Quote Link to comment Share on other sites More sharing options...
jtpfarm Posted September 15, 2022 Author Share Posted September 15, 2022 Do you know anyplace that sells used/refurbished/repairs the FICM if that ends up being the issue? It's my understanding that the VMAC computer has to match the truck Vin and can't be flashed. Is that true? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 15, 2022 Share Posted September 15, 2022 I dont remember about specs. A junk yard may be the ticket.. I hope a few others chime in to answer that one.... I really doubt that is the issue, unless you see obvious damage.. Using todays approach by replacing ECM's is not the way to start on a truck like your's... You have to be a mechanic, not a Tech. You are in good hands here. just keep in touch... jojo Quote Link to comment Share on other sites More sharing options...
jtpfarm Posted September 16, 2022 Author Share Posted September 16, 2022 (edited) I'm definitely leaving replacing them until a last resort. I now have the flowchart for 6-2 and 6-3 code, but the tests are basically impossible to perform when it's such an irratic short term problem. A couple other things I have noticed. 1: I am not able to reset/save the idle speed with the cruise switch like described in the tech manual. It idles at 625 and when I flip the switch 3 times it doesn't do anything. 2: Compared to our 98 with a 427, it idles much rougher. Cab slightly wiggles back and forth while idling. We did put stage 2 injectors and a bigger turbo on but I don't see how that would effect the idle. Not sure if these are related to my issue or just the way this truck is. Edited September 16, 2022 by jtpfarm Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 16, 2022 Share Posted September 16, 2022 2 diff. systems Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted September 16, 2022 Share Posted September 16, 2022 Hmmm?? Quote Link to comment Share on other sites More sharing options...
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