Have you load tested the battery? That's really key to diagnosing no-start conditions -- I'd have thought the dealer would do that, but sometimes they are looking for a more pricey solution rather than just a battery. A JK won't even try to start if the battery voltage drops too low -- and low battery conditions can also cause loss of communication codes to be set (I'd assume that's what they are talking about by "loss of connection" codes) as the various modules can't clearly communicate with each other for a normal start up routine (which is actually fairly complex, as the WCM-PCM-TIPM all need to be communicating to have it start up). IIRC it shouldn't drop below 9.6V or thereabouts -- and this may change too at different times due to changing temperatures, etc. The stock AGM battery is known to not last beyond about 3-5 years as well. You could carry a volt meter with you and if it happens, try to load test the battery at that point and see what it's showing.

 

I wouldn't be guessing and firing up the part cannon at this problem. It will get expensive in a hurry. The best way to do the initial troubleshooting with this is a good scan tool. For a lower amount of money, something like a JScan will work. The idea here is to monitor what the computer is seeing. For example, does the WCM/PCM/TIPM see when the key is inserted, key turned to ACC, RUN, START. Obviously, you'd have to learn what to look for but that is how I'd address this problem. You need to look at the scan tool while the issue is happening. This will divide the system into key input. If that works, then you can look at down stream like starter, starter relay, solenoid, wiring.

 

Hey thanks for the replies. I did find a bad ground wire connection. It seems to have fixed the issue. But I still am testing it to see.

 

Where did you find a bad ground? I have a 2017 doing the same thing. Replaced the battery and still happens every now and then.

 

I just bought a 2017 JK with 35k miles. After putting a 1000 miles on it, I started having an issue. Every-now-and-again the jeep wont start. Turn the key and nothing happens. I checked the sway bar connection, clean and dialectic grease applied. I replaced the batteries in the key fobs, both work, both have the same issue. I removed the TPIM and visually inspected it, and made sure all the connections are good. I did a hard reset of the TPIM too. I also checked the battery connections...also good. Even took it to the dealer. The jeep had "loss of connection" codes. that were cleared and remained clear. The dealer could not get the jeep to repeat the issues. After leaving the dealer the jeep has had the no start issue a few times. The dealer said they cannot diagnose the issue until the Jeep would not start at all...So basically drive it till it dies, hope it dies close to home... Anyone out there have a similar issue? I can replace the TPIM but that's almost $400.00 for a guess. Thanks for any input.

Having the same issue with my 2013 JK. I can usually rock back and forth in the seat and it will then start (no idea why). Can someone explain why OP mentioned sway bar connection? Thank you!

 

Welcome to the forum!
Hopefully you have checked everything the OP mentioned.
I have no idea why the OP mentioned the sway bar connection....Perhaps it was because on the Rubicons it is a common issue for the electronic sway bar connector to cause a variety of strange electronic issues....
In later posts the OP indicated one of his ground connections was bad and it appears by fixing his bad ground connection that resolved his non starting issue. In all probability that is your problem....there are ground connections on the firewall on the passenger side.
In your case it could also be the ignition switch, or a variety of other things...
Please remember to let us KNOW what exactly fixes your problem!

 

Hello all,
New to the forums, but hoping someone here can help. I am having the same intermittent no start on my 2008 Jeep Wrangler. The car was my daughters daily driver, and apparently this issue has been happening for a while. But she failed to tell me about it. She had come up with a crazy “start sequence” that involved opening and closing the driver door a few times to get the Jeep to start.
Here’s what I have thrown at this problem so far:
New starter ($75)
New battery (warranty replacement $0)
Two new starter relays ($18 ea)
New ignition switch in the steering column ($40)
The Jeep is a 2WD Sport X with ~150k miles on it.
$150 isn’t too bad on things that o have read are likely wearing out at the 15 year mark. However, I have reached the end of my willingness to just throw parts at this problem.
Symptoms:
Turn the key and hear an audible “click” and then nothing. Sounds like the starter is trying to engage but then nothing happens. No whining or grinding like a battery issue. Most frustrating thing is that it is completely random. Started fine yesterday and today 7-10 times after I replaced the ignition switch, so I thought I was in the clear. Then this afternoon it had three no starts before it finally turned over.
I read the service bulletin in a previous post, but I am not sure that is my problem, and the bulletin seemed to be lacking in the way of actual instructions.

Any help would be appreciated!
Erik

 

Welcome to the Forum!
Check your battery cables on both ends to make sure they are tight.
Check your fuses, to make sure that they are set in tight.

 

Any aftermarket alarms? Have you checked what Old Dogger suggested? Also check the cables for internal breaks/high resistance.

 

Once again, in all probability your issue is probably a bad ground connection/wire somewhere. Replace the garbage stock JK battery terminals with JK appropriate heavy duty terminal connectors. Please let us know what fixes your Jeep!

 

Gents, Thank you for the responses. I will chase wires this weekend and see what I can find. I did have a new symptom pop up the last two days. Since my original post I have not had another failed start, however, when i start the Jeep it now sounds like the starter remains engaged about a half second too long after the engine turns over. Not sure if anyone has any idea on this or if it helps narrow where exactly the electrical issue could be in the wiring. Thanks Erik

 

All,

I think I have it fixed. Started chasing wire today and saw that the ground that goes to the starter had brittle and cracked shielding. I think that it was occasionally shorting out on the exhaust that runs right next to the starter. I checked continuity from the starter back to the main connector by the driver side firewall, and it was giving ~2-4 ohms. I replaced the blade connector on the ground wire at the starter, and covered the wire in heat shrink and Tessa tape. So far so good. I will update next weekend if it is completely fixed, or as soon as it doesn’t start again if I still have gremlins.
Erik

 

Soooo, that didn’t work. Cleaned all ground connections and checked for security. All the fuses are snug. At a loss at this point.

 

I would start replacing/adding to ground wires. You might have one or two with high resistance. Interesting to note once upon a time the Jeep started with your daughters "magic" sequence. That really tells me you have a faulty wire or switch somewhere. Is it an automatic? If so, play with the shifter a little. Some others have noted if one moves the shift lever forward, it will start. That indicates a neutral safety switch.
Let us know your progress!

 

Where would you tie in another ground wire? Straight to the negative on the battery? To the negative on the starter??

 

For starters you could run a "ground" wire from the fire wall to the engine.....from the alternator body to the engine....to the frame.... you can run "ground" wires anywhere. I run one from my CB antenna mount to the frame! The "ground" wire does NOT have to be connected to the negative terminal of the battery or any other "negative" wire! The JK has several "ground" wires that have been known to fail because of poor connectors, oxidized connection points and fried wires.

 

Update:

never ran any more grounds. The problem did not go away, but was gone for about a week and then popped back up. I was doing some reading before I got to running new wires in the engine bay and found some threads on symptoms of a failed Transmission Position Sensor.
The next time the Jeep failed to start I jiggled the automatic transmission shifter and it started on the next try. This has happened a few more times since, and a firm push forward in the shifter seems to get it to start. Only once have I had to shift it to neutral to get it to start.
At this point I am just going to live with it as it is only happening 1-3 times a week. But a transmission rebuild is probably in my future.

 

You dont need to rebuild the transmission to fix this. There is service bulletin about it.

Its a easy fix and easy to diagnose by yourself too.

2018 Jeep wrangler JK won’t crank over

Hi guy! Question for you, I just purchased a brand new Jeep Wrangler JK 2018 with less than 2000 miles on it. And for some reason everytime I Drive a short distance my car won’t start again. Example; last night I left my house to go food shopping when I was done I went to go start my car and...

www.wranglerforum.com

See link

 

I’ve been battling this for years. Replaced starter, checked existing grounds, nice AGM battery… I just recently added the following wires:

• 2/0 AWG from Alternator power to battery positive
• 2/0 AWG ground from Alternator bracket to battery negative
• 2/0 AWG ground from Alternator bracket to body.

It seemed liked this bumped my voltage at idle from 11.5 (oddly low for idle) to around 14.1, so I figured it fixed the problem and I was finally in the clear.

False. Drove it to the grocery store and sure enough wouldn’t start. I left it there for a couple days and went to go jump it and bring it home because typically that gets mine to start… but I turned the key before doing anything and it started up.

Sounds like we have similar issues, but I’ve jammed the shifter around and it doesn’t seem to do anything.

 

This is insane. How is this possible. Its a common problem (seems like) and not even the dealership is able to fix it? I have the same problem. 2018 wrangler JK. Have replaced the TIPM and other and still. Im at the point that i will let it die. I am not willing to put any more money in this thing. If anyone ever figures it please let us know

 

This is insane. How is this possible. Its a common problem (seems like) and not even the dealership is able to fix it? I have the same problem. 2018 wrangler JK. Have replaced the TIPM and other and still. Im at the point that i will let it die. I am not willing to put any more money in this thing. If anyone ever figures it please let us know

Welcome to the Forum!
Check all of the Fuses in your fuse block, to make sure that they are seated in tight. Since it is a 2018, then your Battery needs to be load tested. Then make sure that you cables are tigh on both ends of the cables.

 

Looks as if this non-start after engine warms up after a short trip somewhere and is turned off for a short time and then fails to start again is a rather common issue.
Obviously there appears to be a plethora of possible causes from every fix suggested in this thread in addition to: #1..removing the plastic engine cover.....#2 Making certain ALL of the wiring loom connections are connected properly...[including the internal connectors within all of the connections] #3... adding insulation to critical wiring loom sections...#4 making certain all of the heat shrouds [like the one for the starter] are functioning properly.
As usual....if a particular suggestion fixes YOUR Jeep, please let us know!

 

If any one knows a mechanic that can fix this in the Denver CO area, please let me know.

 

Try putting Heet into the gas tank.

Or jiggle the steering wheel left and right.
Mine did the same thing. So give these a try.

 

What is the problem with this? Seems to be a common issue. I started having trouble with my jeep starting for years and now I even have a new engine in it, and starter. It seemed like the problem was "solved" by pushing the shifter forward. Today that no longer works. I've added a ground. I need to figure this out.

 

My 2017 wrangler has a intermittent no start continuing to crank issue throws a bunch of codes. Found some green corrosion on neg battery terminal. Cleaned and issue disappeared. Until next time.