Ethan Owner/Technician Kentucky Posted Latest Edited
2012 Nissan TITAN SL 5.6L (VK56DE Flex) 5-spd (RE5R05A) — 1N6BA0EC1C⦁⦁⦁⦁⦁⦁⦁
Start-Stalling
Vehicle came to us, has previously been to 2 other shops, one of which a Nissan Dealer. Customer complaint, vehicle will start and stall almost immediately. Scanned, no codes. Vehicle will start and run, then die 5-10 seconds later. Check engine light will briefly illuminate when engine stalls. Leaves no codes. Noticed while monitoring scan data, scanner communication drops with all modules when engine dies. Confirmed this with 3 seperate scan tools. Communication is restored within 10 seconds after engine stalls. Scoped CAN lines for activity, activity present during condition. Checked K-Line, Solid 11-12v signal with no pulses to ground while engine is running, or during stall condition. Checked IPDM relay output/input from ECM, both good during condition, relay is not pulling power from ECM. Checked all other ECM powers/grounds, all good during condition. Checked AC Voltage, 180mV difference. Unhooked alternator, engine starts and runs, does not stall. Let engine run for well over a 2 hours with no alternator, never died. Hooked alternator back up while running, engine died within 30 minutes. Seems that once engine warms up, engine runs longer before stall. Replaced alternator with OE, did not fix. Unhooked alternator and installed battery charger. Varied voltage with engine running. Engine will not stall under 13.2v. Engine will typically stall anywhere between 13.2 to 14.5v. KOEO, varied voltage all the way to 15.2, scanner communication never drops without engine running. I have a used ECM on the way, but do not feel very confident that it will fix this issue. Has anybody dealt with anything like this in the past?
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Interesting
AiDN AI Assistant
California
AiDN
This is a reply from an experimental AI-powered advisor. It is important to exercise caution, verify information from multiple sources, and make informed decisions based on the prevailing circ*mstances.
Ethan, it sounds like you've conducted thorough diagnostics. The issue with the alternator and voltage sensitivity is intriguing, especially since replacing the alternator didn't resolve the problem. This suggests a possible issue not directly with the alternator itself but perhaps with how the ECM is interpreting the voltage or managing the electrical load.Given the symptoms and your testing…
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Ken Owner/Technician
Arizona
Ken
dwell time changes at the coils depending on voltage…higher the voltage the less on time needed to charge the coil…seen a vehicle run bad with the alternator hooked up and run fine with the alternator disconnected….ended up with bad aftermarket coils someone had installed….this probably is not your issue, just something i had see. If a coil is spiking it can shut the pcm down but, to lose all…
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Ethan Owner/Technician
Kentucky
Ethan
As weird as this one is, i could see it make sense. Will check them this afternoon considering it won't take but a minute. Used to seeing the Fords blow the drivers out due to faulty coils, would typically only affect that one driver on those. That theory would definitely prove as to why the communication issue is only present during KOER
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Glenn Owner/Technician
Texas
Glenn
Hi Ethan,This will sound strange but check the coolant for Voltage with a multimeter. Negative lead of the meter on battery Negative and hold the Positive lead in the coolant without touching anything metal. Set DVOM on the millivolt scale. I have had a few situations where the coolant has aged and started to act like a “battery” from the reaction of different metal and corrosion that…
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Ethan Owner/Technician
Kentucky
Ethan
I'm open to all suggestions!140-160mV, no change battery hooked up, disconnected, KOEO, or KOER
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Marcus Technical Support Specialist
Florida
Marcus
Unplug the transmission then start the truck see if it stalls after 10 seconds tcm causes major problems in these nissans if you lucky itll start on the key no theft coded tcm if your not youll have to jump the starter relay in the ipdm theft active tcm disables starter circuit if the truck nows runs and does not stall suspect faulty tcm can circuits or water intrusion in transmission due to…
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Ethan Owner/Technician
Kentucky
Ethan
Likely won't start due to unknown gear position, but ill jump the relay and see what it does!Update: Had one of my guys start the truck while i was underneath. As soon as engine started, unplugged transmission, stall condition still present. Good idea tho, have seen the coolant in transmission issue a few times and had forgotten all about it.
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Ethan Owner/Technician
Kentucky
Ethan Resolution
Update: Replacement ECM fixed it!
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Thanks
