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Discussion Starter · #1 ·
I have been trying to figure out a no start issue with my 2007 JK Rubicon 2-door for a month now and have gotten nowhere.*

One day, I pull my jeep out of the garage and turn it off to clean the wheels. When I get back in to start it a couple hours later, I get nothing. No click, no sound when i turn the key, just nothing.*

A scanner will not communicate with the Jeep, I have tried multiple. I also get the security light, lots of dash light on, sway bar light flashing, once I noticed it said hot oil on the odometer also but haven't seen it since.*

I have tried a different tipm, put the factory head unit back in (recently replaced it), put new ECM in with the SKIM removed thinking it was maybe the WCM, Unplugged the sway bar and took out the sway bar fuse, I still get nothing, no change in symptoms.*

Has anyone else had this problem and fixed it? I'm not sure what to do next. It didnt have any problems before this happened and started up and drove fine every time.*
I have read countless forums and haven't found a solution yet. Any help would be appreciated.*
 

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The way it sounds, it's like something is wrong with the CAN network. You might need someone that can troubleshoot something complicated like that. Usually you need a scope do diag that.

One thing you can try is look what is on the CAN network. Unplug modules on the network and try your scanner. There may be a module that is taking the network down. If you get lucky and find the bad module then you can replace from there.
 

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I have been trying to figure out a no start issue with my 2007 JK Rubicon 2-door for a month now and have gotten nowhere.*

One day, I pull my jeep out of the garage and turn it off to clean the wheels. When I get back in to start it a couple hours later, I get nothing. No click, no sound when i turn the key, just nothing.*

A scanner will not communicate with the Jeep, I have tried multiple. I also get the security light, lots of dash light on, sway bar light flashing, once I noticed it said hot oil on the odometer also but haven't seen it since.*

I have tried a different tipm, put the factory head unit back in (recently replaced it), put new ECM in with the SKIM removed thinking it was maybe the WCM, Unplugged the sway bar and took out the sway bar fuse, I still get nothing, no change in symptoms.*

Has anyone else had this problem and fixed it? I'm not sure what to do next. It didnt have any problems before this happened and started up and drove fine every time.*
I have read countless forums and haven't found a solution yet. Any help would be appreciated.*
I had this on my 08 JKUR. I disconnected the negative side of the battery, no help. Then a buddy said to disconnect both neg and pos of the battery. I did and boom the Jeep started.
 

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I'd say if the OBD scanner isn't communicating at all, I'd check the grounds on pins 4-5 (a lot of info online about diagnosing OBD ports online), and then go around and check all of your ground points. Remove both battery terminals as said above from the battery as well. Hoping for a simple solution of course. If you're not the original owner I'd check and remove any aftermarket stuff that's wired into the electrical system as well. My hope/guess is that someone has installed some things and there is a bad ground somewhere.

You can get a cheap factory service manual online at the link below (I've used the same seller) and read up on replacing the ECM, WCM procedure. I'd imagine the older models are similar -- if the PCM/ECM or WCM is replaced, there is a procedure using a factory (or similar) scan tool to transfer the SKIS secret key that is unique to the WCM. It's not a simple swap out procedure, which you may know but in this case the service manual will be a big help. There's also a procedure with the TIPM outlined in the manual (at least on newer model JKs). But obviously you'll need a working OBD port first to do any of the above.

https://ebay.us/OKg6mq

Let us know how it goes. Good luck!
 

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Discussion Starter · #6 ·
Thank you for the replies!

Yes, I new Odyssey Extreme Battery! I have disconnected both terminals multiple times with no luck. All the grounds I have been able to find so far look good.

Do you know, or know where I can find out what modules run on the CAN Network? So far I have unplugged the Radio, Amplifier, sway bar, and evap solenoid and no changes.

I did test the grounds on pins 4 and 5 and they are both good, I also checked the pin 16 and read good (battery voltage). I am still trying to find the wire diagram for the rest of the pins and what they are supposed to read at. I bought a service manual download off ebay but they are not searchable and I'm having some trouble locating it.

The new ECM I bought I had the SKIM Completely removed to bypass the WCM and any security features, thinking that was what my problem was, but nothing changed. I had actually bought a new WCM earlier and took it in (towed it) to get programmed which was when I found out the OBD port was not responding.

I've read about adding more grounds sometimes solves things like this, but I'm not sure where to ground to? Any suggestions?
 

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I’d have to look up in a service manual to see what all modules are on can. But I’d try the sway bar and also abs. Both get a lot of rain and or snow spray.
 

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Below is a link to my 2014 3.6 view of the ECUs on a clone of the dealership Witech 1.0 system -- maybe someone else with the 3.8 could chime in as to whether this is similar with yours? As you can see it goes directly to the TIPM, so I guess I'd start there. I'd think *something* should be loading there unless the TIPM is down. What scan tool are you using, and have you double checked it on another working vehicle?

https://drive.google.com/file/d/1OwGoAVdkx6icOPto0xgDp_dTYlU_PvVU/view?usp=sharing
 

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One idea: You should be able to retrieve the basic codes that are set w/o the OBD2 port with the info at the link. However, if you're PCM has been replaced and not coded to the vehicle and WCM module, I'm not sure how far you'll get doing this: https://www.cjponyparts.com/resources/jeep-wrangler-check-engine-codes

In the manual for my '16 there's a "computer data lines" section in the wiring chapter that shows the data link connector and its 16 pins. On the '16 pins 4-5 are grounded at the left kick panel, Pin 6 CAN C(+), Pin 14 CAN C(-), and Pin 16 goes to fuse M30 15A (all of course in the TIPM). So M30 would be something to check if yours is the same. It also controls the front wiper motor on a '16. Your manual should have something similar.

There's also a chapter in mine about a TIPM and WCM equipped no crank situation, I'd check your manual for that.

That said, the factory manual goes over writing the VIN to the new PCM (or ECM as you're calling it), which I assume has been done? And if you have the SKIM (sentry key) system, the "secret key data" has to be transferred to the new PCM from the WCM using a scan tool as well. If those aren't done, I'd assume that'll be a literal non-starter. And I don't believe you'd be able to just unplug the WCM and expect it to start, as the TIPM communicates w/ the WCM and then allows the start up sequence to begin.
 

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Discussion Starter · #11 ·
No change with sway bar disconnected. I have also tried unplugging ABS, Amplifier, Radio.

Thanks for the diagram, I will try the modules on there.

Somthing else I've noticed, somtimes when I turn the key none of the dash lights come on. It's like its dead, but if i push the brake or open a door it "wakes up" and all the dash lights come on.

I added another ground from the alternator to the battery and put new battery terminals on as well, no change.

The new computer was programmed to my VIN and the SKREEM (security system) was completely removed from the computer. So in my understanding, it should not be a security issue anymore. This is what was done to the new computer https://www.ebay.com/itm/Dodge-Jeep...angler&hash=item1a878644c8:g:w7EAAOSwjPVdrzG2

My friend is bringing over a nice snap on scanner today from NOVAK (local here) to see if we can read anything from it.
 

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Why did you remove the SKREEM from the PCM in the first place? Seems a lot more difficult than just fixing a WCM module.
 

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Discussion Starter · #13 ·
Why did you remove the SKREEM from the PCM in the first place? Seems a lot more difficult than just fixing a WCM module.
Replacing the WCM is one of the first things I tried to do. That is when I found out the OBD port was not working because they tried to program the new WCM but they couldn't connect. So I figured it was the pcm that was bad, so I ordered a new pcm and just had the Security deleted from it so I wouldnt have to deal with it in the future.

Heres what happened yesterday:

My Friend from Novak brought over snapon scanner. We were able to connect and read the CAN system and we got the code U0001 for CAN C Bus. We were unable to connect to any of the other systems like engine, transmission, etc.

We then disconnected all modules on the Can C bus network, and we still were getting that error code and unable to communicate with the other systems.

Then we checked the Can C bus wires at the TIPM. When disconnecting the harness at the TIPM the code was gone and we were able to connect to all systems and a normal cheap obd scanner could now connect. We decided there is probably a short somwhere in the CAN C bus wire somewhere and it wasnt a module because we disconnected all the modules.

We then cut and spliced new wires from the TIPM straight to the PCM to bypass all the modules to see if it would start. the error code is now gone and we can connect to all systems, but the Jeep still does not start. Does the same thing.

My question now is does anyone know what the minimum requirements are as far as what modules need to be connected to Can C to be able to get the Jeep to start?
 

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You have a new TIPM, correct? If so, there's a procedure in the '14 manual for it's replacement: "Insert the ignition key and turn it to the "RUN" position and wait twelve seconds. The TIPM will collect the necessary vehicle configuration and VIN data from the CCN and PCM at this time. After twelve seconds turn the ignition key to the "OFF" position and then back to the "ON" position and verify proper vehicle systems operation."
 

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Replacing the WCM is one of the first things I tried to do. That is when I found out the OBD port was not working because they tried to program the new WCM but they couldn't connect. So I figured it was the pcm that was bad, so I ordered a new pcm and just had the Security deleted from it so I wouldnt have to deal with it in the future.

Did you ever fix it and get it running? Having same issue here.......

Heres what happened yesterday:

My Friend from Novak brought over snapon scanner. We were able to connect and read the CAN system and we got the code U0001 for CAN C Bus. We were unable to connect to any of the other systems like engine, transmission, etc.

We then disconnected all modules on the Can C bus network, and we still were getting that error code and unable to communicate with the other systems.

Then we checked the Can C bus wires at the TIPM. When disconnecting the harness at the TIPM the code was gone and we were able to connect to all systems and a normal cheap obd scanner could now connect. We decided there is probably a short somwhere in the CAN C bus wire somewhere and it wasnt a module because we disconnected all the modules.

We then cut and spliced new wires from the TIPM straight to the PCM to bypass all the modules to see if it would start. the error code is now gone and we can connect to all systems, but the Jeep still does not start. Does the same thing.

My question now is does anyone know what the minimum requirements are as far as what modules need to be connected to Can C to be able to get the Jeep to start?
 

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Discussion Starter · #16 ·
Figured I'd update you all with the solution I ended up finding! I had installed some aluminum inner fender liners, and one of the screws went into the wire harness into the canbus wire. The wire loom was directly behind the fender liner hole.... terrible design!! It was a massive headache and ended up being that after tearing apart the dash, removing entire wire harness, etc. The weird thing is I had the fender liners on for over a week and had taken it on trails, etc. and it decided to wear all the way through after backing it up 20 feet, which made it hard to figure out! Thanks for the input!
 
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