Do I need a new PCM?

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purevw

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Has anyone considered the possibility that the transponder in the ignition key may have failed or is otherwise not being sensed or approved by the vehicle? I would try to verify that before pretty much anything else. Is there a second key that might be tried?
 

RICHNARDONE

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had this problem with my 08. seems the fuel pump shut off went bad. actually reset once when i was driving with some pavers in the cargo area and went over a speed bump, the impact of the bricks tricked the car into thinking it was in an accident
 

RICHNARDONE

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fuel cutoff impact switch? try to reset it. it's in the back in the cargo compartment behind a small panel on the left side. mine went off once when i went over a speed bump with some pavers in the back. luckily found it out before the tow truck was called. a few years later, it went off again because of a loose connection and started to melt. i removed it and shorted the wires together as a temporary fix (3 years ago!)
 

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Brandonian

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This is the fun in troubleshooting on a forum, and I love it when the ideas pour in :0) - All good places to check...told you I was a backyard mechanic :0
 

D Hook

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Wife's expedition did this once. Hers was a2010. She was on the interstate and it just shut off. Had it towed to a dealer who diagnosed a bad module back near the fuel pump. Don't recall the name of the module (had something to do with fuel but it wasn't the pump itself) or much more about it but replacing it fixed everything.
 

RICHNARDONE

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Probably the fuel pump cut off switch that is supposed to get activated during an accident. Supposed to stop the pump from emptying the tank onto the ground if a fuel line gets cut. See my other post to see the location
 
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tstripe76

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Thanks Steve and Honocor, I will check both of those, however I have come across another issue which may also be the cause. I decided to go the route of checking (and changing due to milage) the timing. Got the cover off and all looked good, and while the chain was nice and tight, based on what I found, the right bank looked to be half a tooth off. So i kept going and was removing the roller followers, and on cylinder 2 I found a spring just floating loose, with no valve. I pulled the plug and the end of the plug is all knarled up, so I know the valve is busted and floating around down in the cylinder. So now i gotta pull the head (the plug holes are too small for my scope camera) to see how bad it is......
 
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tstripe76

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Well, found the issue. Two broken intake valves on cylinder 2. Found most of the debris up inside the intake, bit still cannot find one of the valve stems. Big hole in tje top of the cylinder head and big chunk of one of the valves jammed under the exhaust valve. Cam lobe all tore up too. Well, at least it wasn't the pcm.....
 

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tstripe76

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Well, someone finally told me that this truck (my neighbor's) had a ticking type noise for a while, so I wonder if the valve was sticking and finally just got stuck. Anyway, got a used engine, dropped it in, and everything is good.
 
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