2012 Wrangler JKU, no start, no crank issue continues

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twodogs112

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Jacksonville, florida
Ok my issues are still ongoing. To recap, random no start no drank after driving about 30 minutes. I can get it to start by using the battery cable remove, touch, reconnect . All power is on and works when this happens. Jeep specialist had it for a month, replaced the ignition. Threw codes regarding skim codes. Went to dealer, estimated $1200 to replace skim module. I ran a new ground cable from neg to alternator. No bad grounds to engine block . No trans temp issues. Very hard to get the skim codes to read. No other codes read. Replaced entire engine wiring harness with mopar factory parts. Won’t start in neutral, or in 4 low. Starter is good, new battery, etc! New batteries in all keys. Very frustrating.

Here’s my questions. Has anyone used the reprogramming service to remove the skim module successfully? If so who do you recommend? I’m not 100% sure that the skim module is bad. The problem only occurs when it has been driven awhile. No blinking, or constantly on anti theft light any time!! Next time this happens I’ll do the fuse pulling thing. Before I reset with the battery cable.
I really don’t want to take to the dealer and spend$1200 just to see if it works. I have searched all the you tube, forums, google search, nothing matches the problems with this. Any ideas? Thanks.
 
Do you still have the junk Factory battery clamps on, if so they need to be replaced with some HD ones?

Do you have a little red dot in the upper right corned of the dash cluster when this happens?
 
Ok when you say no start no crank, do you mean when your turning the key to start it the starter does nothing?

Also if this is so does your dash lights come on as normal?
 
Yes starter does nothing, no click, nothing. As my previous posts have noted. Everything electrical works. The only warning light is the lightning bolt, and cel, both go out after a short time. No anti theft light other than the initial come on.

What I have done recently, other than visit two local Jeep dealers (est to replace skim module, $1200). Added a new ground wire from negative battery to alternator. Checked ground wires to engine block on drivers side(ok) , looked at wires to starter(pos and neg) appear to be ok, just went out and pulled cover off steering column. Looked at wires coming out of skim module, no rips, tears, crimped wires, looks good from the outside. Replaced batteries in all three keys, checked with locksmith again regarding the signal from the keys, all good.
Really don’t want to pay dealer $1200 to replace skim, if that’s not it. Has anyone been successful with a skim delete service (delete) from the computer?
Oh, just out of curiosity, I pulled up on the j13 fuse, and it started right up. Is this normal or right?
 
Ok a couple other things, Is your trans a auto or manual?

Have you tried to jump the starter at the starter to see if it works when the key won't make it work?
 
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Auto trans. Jeep specialist tested starter current and connections. All good. He also tested when the malfunctioning was taking place. With direct connection to battery, starter worked. Also, while non starting, checked fuel injectors for fuel flow. They worked for a nano second, then shut off. Hence, his thought of anti theft issues.

Could this be a main computer issue? The engine has a new factory wiring harness. Maybe it might think the keys are not correct intermittently. I rarely get the skim code’s malfunction. In fact , only once when this happens. No codes at all most of the time. It has to be electrical!!! Bad ground somewhere. I did have to rewire one front headlight when I upgraded to led. The lights work fine, no flickering, etc. could that be it?
Sorry to be a pain. It’s just frustrating. I know when it’s figured out it will be something stupid! Thanks for the ideas.

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twodogs112 said:
Auto trans. Jeep specialist tested starter current and connections. All good. He also tested when the malfunctioning was taking place. With direct connection to battery, starter worked. Hence, his thought of anti theft issues.
Click to expand...

This is what i'm having trouble following.

If he tested it when it was malfunctioning and when the key was on to start it the starter worked?

Do you have another Key that you never use to try it?

When my battery was weak in my Key FOB it wouldn't do anything, replaced my FOB battery and all was well and haven't had another issue for 4 years.

Also the automatic transmissions have a issue with the neutral safety switch which is in the trans. That could explain when it's hot it won't start and it cools off it starts.
 
Ok, to be specific. When the no crank no start occurs. Everything works, lights radio, ac, etc. the only warning lights on are, lightning bolt, cel, no others. Automatic transmission, does not start in neutral or 4 low. Does not start wiggling shifter. Replaced all batteries in keys. Keys checked by locksmith for signals, all good. One old and very worn factory key, two new keys. Also did a delete all keys on JScan and reprogram all keys again.

When jeep tech had the ncns occurred at his shop. Tested the starter bypassing all functions. Running direct from battery to starter. Starter cranks fine. He tested for a faulty trans neutral switch (current?) said it was fine. Not showing any codes regarding this. So I’m stumped!!! Thanks for your ideas.
 
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twodogs112 said:
Auto trans. Jeep specialist tested starter current and connections. All good. He also tested when the malfunctioning was taking place. With direct connection to battery, starter worked. Also, while non starting, checked fuel injectors for fuel flow. They worked for a nano second, then shut off. Hence, his thought of anti theft issues.

Could this be a main computer issue? The engine has a new factory wiring harness. Maybe it might think the keys are not correct intermittently. I rarely get the skim code’s malfunction. In fact , only once when this happens. No codes at all most of the time. It has to be electrical!!! Bad ground somewhere. I did have to rewire one front headlight when I upgraded to led. The lights work fine, no flickering, etc. could that be it?
Sorry to be a pain. It’s just frustrating. I know when it’s figured out it will be something stupid! Thanks for the ideas.

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View attachment 128203
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Just throwing it out there again... In your first picture the positive clamp does not look like it is seated all the way down. I had this issue when I first acquired my JK... No crank/start. Loosened up the pos terminal, took a socket and tapped the clamp down as far as it would go. It was ~1/16" high on the post. Hopped back in and it fired right up.

I would do this on both pos and neg to be sure they are fully seated. Its a horrible design and leaves no margin of error.
 
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Update, after several days of driving the no crank no start came back. I pulled the m13 fuse. And it started right up. So my issue seems to be with the anti theft system. Again, when this happens the anti theft light does not stay on. I’ll be investigating the skim unit next. The dealer wants $1200 to replace. Seems a bit high. I’ll keep you all posted. Thanks for the ideas.
 
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twodogs112 said:
Update, after several days of driving the no crank no start came back. I pulled the m13 fuse. And it started right up. So my issue seems to be with the anti theft system. Again, when this happens the anti theft light does not stay on. I’ll be investigating the skim unit next. The dealer wants $1200 to replace. Seems a bit high. I’ll keep you all posted. Thanks for the ideas.
Click to expand...


Can't you just leave the m13 fuse out, have you tried that?
 
That’s probably what I’ll do for now. At least until I research the dreaded anti theft system more. Just happy it’s not the transmission neutral switch.

One thing I find most interesting. On my 69 mg midget, repairing and maintenance is so much easier without all the systems car manufacturers think we must have. Anti theft on a 69 is just the”club” across the steering wheel. My wife loves the jeep, I’ll just keep fixing it!. Thanks all.
 
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