bchandler Posted July 17, 2021 Share Posted July 17, 2021 Anyone know why on a 2012 Pinnacle with MP8 / Mdrive went to crank it and it turned over few times but let off the key, turned off, then back on, and now it won’t turn over. Checked fuses, fuseable link, disconnected battery cables, filled truck with air, and still won’t turn over. Any suggestions? Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/ Share on other sites More sharing options...
Joey Mack Posted July 18, 2021 Share Posted July 18, 2021 what was the most recent repairs??? Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-476990 Share on other sites More sharing options...
bchandler Posted July 18, 2021 Author Share Posted July 18, 2021 Really hasn’t had anything done lately. Just little a/c work and a service done back in February at dealer. Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-476998 Share on other sites More sharing options...
Joey Mack Posted July 18, 2021 Share Posted July 18, 2021 so when you turn the key, the starter doesnt engage? or does it turn over but not 'fire'? theres so many things that can cause this,,, chaffed wires on the tranny harness, fault codes, PTO issues, too many sensors!! can you plug in and test/ read codes/ etc.? good contact at the starter? jojo Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-476999 Share on other sites More sharing options...
bchandler Posted July 18, 2021 Author Share Posted July 18, 2021 Starter not engaging. Doesn’t turn over. Doesn’t even try to. Only hear the relay click in the upper dash fuse panel. It threw several codes. Called Mack dealer and said it has zero communication with one of the ECMs. I attached pics of the codes. They said the FMI 9 code means zero communication. Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477000 Share on other sites More sharing options...
bchandler Posted July 18, 2021 Author Share Posted July 18, 2021 Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477001 Share on other sites More sharing options...
bchandler Posted July 18, 2021 Author Share Posted July 18, 2021 Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477002 Share on other sites More sharing options...
bchandler Posted July 18, 2021 Author Share Posted July 18, 2021 I don’t have any way to plug in and test it. Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477003 Share on other sites More sharing options...
Joey Mack Posted July 18, 2021 Share Posted July 18, 2021 have you tried to jump the celenoid at the starter with the key in the run position? then you can take it in to get the TCM flashed... 1 Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477031 Share on other sites More sharing options...
bchandler Posted July 18, 2021 Author Share Posted July 18, 2021 I haven’t yet. I was wondering if it would mess up any sensors or other sensitive stuff Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477053 Share on other sites More sharing options...
Nobody454 Posted July 18, 2021 Share Posted July 18, 2021 (edited) i had a main battery cable from the battery to the starter that had a bad spot in it. a real hard corroded section of the big red cable going to the starter. no crank. 2012 CHU Edited July 18, 2021 by Nobody454 Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477054 Share on other sites More sharing options...
bchandler Posted July 18, 2021 Author Share Posted July 18, 2021 Did it throw codes like the pics I posted? Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477057 Share on other sites More sharing options...
bchandler Posted July 18, 2021 Author Share Posted July 18, 2021 @Joey Mack - I just tried jumping the solenoid and it spun over a bunch but wouldn’t fire off. As if wasn’t getting fuel. Could that be a safety feature since the codes are on it? Or something else? Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477060 Share on other sites More sharing options...
Onyx610 Posted July 18, 2021 Share Posted July 18, 2021 Since you haven’t had any recent repairs and don’t have PTT. I would suggest starting to look at modules connectors, pins, and harness’s for a start. Also the VECU is programmed to perform several functions including starter control and ignition key switch. Hopefully some more guys that have a lot more knowledge on this will have some input for you. Joey is one of them. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477068 Share on other sites More sharing options...
Joey Mack Posted July 18, 2021 Share Posted July 18, 2021 there should be a "Fuse link" in the batt. box.... its a short/seperate cable that goes to the frame. it's aground breaker... I'm pretty sure I'm right, they will dissable the truck when they fail. Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477073 Share on other sites More sharing options...
bchandler Posted July 18, 2021 Author Share Posted July 18, 2021 Yes sir the dealer had me check this Friday when I was on phone with them. They didn’t have a mechanic to send me so he was helping me best he could. We checked the fuse link in batt box by bypassing it with jumper cables. It was still good. Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477077 Share on other sites More sharing options...
Nobody454 Posted July 19, 2021 Share Posted July 19, 2021 6 hours ago, bchandler said: Did it throw codes like the pics I posted? it did throw some codes, but I dont remember them. nothing like you have going on though Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477081 Share on other sites More sharing options...
Joey Mack Posted July 19, 2021 Share Posted July 19, 2021 Has anyone suggested a new gear selector assembly, I have replaced a few of them.... truth is, when i did that, its was a guess and twice it didnt work.. any chance you have another truck or a friends truck that you pop the selector out and test yours??? long shot.... These are tough issues to fix without P.T.T. As a mechanic it Chaps my Ass.... stay with us and the answer will come. Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477082 Share on other sites More sharing options...
bchandler Posted July 19, 2021 Author Share Posted July 19, 2021 Man I don’t know anyone else local that has mdrive that would let me try it. I planned to call dealer back in morning and see if they can have Mech run out and plug into it. They said it would have to be at dealership to flash so may have to have it towed 😕 Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477083 Share on other sites More sharing options...
Joey Mack Posted July 20, 2021 Share Posted July 20, 2021 Any luck? Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477117 Share on other sites More sharing options...
bchandler Posted July 20, 2021 Author Share Posted July 20, 2021 Mack guy came out. Turns out it is the engine ecm. Had little oil at plug from a leak that got in the harness they said. Called wicking effect. Apparently it’s so common they have a term for it! Put a test ecm on it, cranked up, drove it to dealer to get a reman installed and fix leak. Thanks for all the help! I’ll be back at some point im sure! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477128 Share on other sites More sharing options...
Joey Mack Posted July 20, 2021 Share Posted July 20, 2021 very common Quote Link to comment https://www.bigmacktrucks.com/topic/67387-2012-pinnacle-won%E2%80%99t-crank/#findComment-477162 Share on other sites More sharing options...
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