Dash Lit up Loss of Steering

[gato]

I got mine fixed. Spent time at the dealer working one-on-one with tech. Brought my printed scans to them. Got a tech that was willing to trace the harnesses.

He found and fixed the problem. I was not willing to wait for a back-ordered harness, so I approved having the wire that was shorting out repaired. I tested for a day and it is all good.

Details:

*** In my case the wire bundle that runs near the transmission bell housing had worn out due to vibration/heat/rubbing. It was repaired. I still don't like how that harness looks and may do further work on my own to protect the wires.

Below is the dealer resolution and a picture.

*** I hope this helps others - lets build a forum database for places to look when we have these electrical faults ***

P.S. This area is incredibly hot and exposed. I frankly find it odd that Jeep has all these sensitive wires routed as they are!!!

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[yotajeeper]

Man this is one scary thread!

 

[DNNDRTY]

Okay so from all my research I've done on this all the fuses I've seated, batteries changed, grounds, re grounded and plugs verified the one place I have found to have a loose connection issue is the Green Buss block behind the glove box.

Make sure all the plugs are fully seated. I have found that if I clear the codes to blank and drive around when my dash lights up I can reach over and tap,push,shake,jostle the wires going into this box and it shuts the majority of the codes off primarily the BRAKE light which with my Automatic it prevents me from shifting out of gear. There is no rhyme or reason, no standard "it happens when I do this" to these problems. This is the only "fix" I have found to maintain it.

I have priced out the harness and block where unfortunately you can not buy them seperate and it's close to 800 for my specific Jeep.

If you guys have any questions and want to reach out to help troubleshoot I'm happy to help. My cell is 603-381-3742 I own Predator Trail Gear and have been diagnosing this issue with the help of a few friends at other companies and this is the farthest we've come.
Hope this helps good luck.

Also I have seen more times then not the harness on the Rubicons to the swaybar disc is a problem. If you have a warranty USE IT unlike I have had the ability to.

My jeep lights came back on over weekend. Jeep was giving me trouble with shifting and going into gear. Dropped it off at dealer and they said it threw almost 90 codes. Tech referenced bad wire connection on green bus near glove box. Tech traced it to the abs/brake module connector on bus and could duplicate issue. Service writers comments "Traced issue to a spread terminal in connector C7 of the CAN C IP STAR connector. Tightened terminals in C7".

Fingers crossed this is fixed now.

 

[jmj52876]

My jeep lights came back on over weekend. Jeep was giving me trouble with shifting and going into gear. Dropped it off at dealer and they said it threw almost 90 codes. Tech referenced bad wire connection on green bus near glove box. Tech traced it to the abs/brake module connector on bus and could duplicate issue. Service writers comments "Traced issue to a spread terminal in connector C7 of the CAN C IP STAR connector. Tightened terminals in C7".

Fingers crossed this is fixed now.

Ok, just saw this thread and I'll tell you what they found with mine. This same exact occurrence actually happened to my Gladiator Rubicon. When I say exact, you explained my ordeal just as I lived it. It took 3 trips to the dealership before they opened a STAR case. They sent one of the computers to an engineer at Jeep and he ran tests. He came back and said it was the electronic power steering module. It was shorting out, and in turn, freaked the whole system out. Not to mention, total loss of power steering.
They replaced that part, also for safe measure checked all wiring harnesses. Have had it on the road now for over 8000 miles and not one glitch, hiccup, nothing. I plan to replace all that electronic crap for a PSC system soon.

 

[LePogoQC]

Hey guys sorry for reviving this but I feel like there is still very few information on how to diagnose this by ourself.

My girlfriend's JLUR started the same simptoms as you describe. But dealerships in my area have very bad service departments and the warranty on her JL is over because of the mileage. For theses reasons Id rather fix it myself.

VEHICLE SPECS
- 2019 Wrangler JLU Rubicon, with 8.4 Uconnect, Alpine sound, Canadian Model, heated steering, seats, No park assist, no driver assist (blindspot alert)
- Aftermarket Quadratech ditch lights (installed properly for a long time before symptoms started) (The switch use power at the 12v outlet.)
- Pedalbox (installed properly long before problems came, tried unplugging since, problem persist)
- Aftermarket taillight from vividlumens (installed long before, always made some codes in the dash when using turn signal but worked properly, Tazer JL later fixed the issue by switching back and forth between halogen/led settings in the menu. Now this doesnt throw any codes)
- Fenders are cut, the DRLs and front turn signal are currently absent / unplugged, plugs are properly sealed from debris, Yes it throws codes for turn signal out or open circuit. It was this way long before the problem came..
- Smittybuilt 10K Gen2 winch, installed properly very early when she got the jeep, works good.
- Tazer JL Mini, Installed after the problem came, I was looking for a SGW bypass to be able to diagnose the jeep, decided to go with the Tazer since I was already planning to buy it one day and this also work as a security bypass for the 2018+

Now that you know what's installed on the Jeep here are the simptoms:
- Can drive without issue most of time. will eventually happen at a full stop or doing highway speed after at least 30mins of driving.
- Dash lits up with lots of module saying needs to be checked. (ABS, Traction control, Swaybar disconnect, 4wd, etc) when it lits up, tach will also reset (needles cycle from 0 to full on both rpm and speed like yen you start it.)
- sometimes lost of powersteering while driving, stopping the engine and starting back on will make it work again. (its an electric pump so its still an electrical issue, when it works it works great)
- sometimes will lock in park when at a full stop. even if the transmission is in drive, D will start flashing and the autopark will engage, then there is no way to go back in drive unless you shut down the engine and start it back.

Now here are my codes taken during one episode of the jeep acting up with powersteering loss :

PCM : 11

• U0121 (lost communication with antilock brake module) refer to 28
  
• U11BF (lost brake pedal position message) abs over can-c
  
• U0129 (lost communication with brake system control module 1) refer to28
  
• U1141 (lost esp torque request message) abs over canbus
  
• U0125 (lost communication with dynamics sensor) refer to 28 (entre ORC et pcm)
  
• U11BC (lost brake switch message) between pcm and abs over can-c
  
• U1120 (lost wheel distance message) between pcm and abs over can-c
  
• U1110 (lost vehicle speed message) between pcm and abs over can-c
  
• U120C (lost brake booster signal) between pcm and abs over can-c
  
• U12A8 (lost communication with master cylinder pressure sensor) abs over canbus
  
• P057C (brake pedal position sensor circuit low) abs over canbus

BCM : ModuleNoResponse (BCM wasnt responding when scanning but it normally responds)

TCM : 2

• U0001-00 (can-c bus) can c signal missing or performance refer to 28
  
• B0121-00 (cant find it in mitchell or alldata)

ABS : 2

• C1252-92 (vacuum pump failure) refer to 28
  
• B0002-00 (driver frontal squib 2 short) related to ORC / refer to 28 orc

DTCM : 2

• U0121-00 (lost communication with antilock brake system control module) refer to 28 bcm
  
• P0415-00 (secondary air injection ??)

RFH : 1

• U0121-00 (lost communication with antilock brake system control module) refer to 28 bcm

ORC : 1

• U0001-00 (high speed can communication bus)

So long story short.. 90% of the codes are about communication in Can-c channel. and most of the codes are about the abs module. Note that when it acts up, the ABS module is still working. the jeep does have working ABS when this happens even with the lost communication messages.
The first real diagnostic seems to be to follow (Refer to 28 - DTC-Based Diagnostics/MODULE, Body Control (BCM) /Standard Procedure).
wich uses a lot of WiTech 2.0 functions. I tried getting a chineese version of Witech 2.0 but It can only communicate with 2017 and older models. event with the SGW bybass installed.

So I'm kind of frustrated I cant follow proper diagnostic steps without the dealership tool. Anybody had any luck with a quality scan tool like SnapOn or else diagnosing Can-bus in a JL ? I know this wouldnt work without a SGW bypass but since I already have it, I should be able to use the tool??

For now I go blinfolded with my multimeter trying to check simple B+ power to modules, ground to modules, and Can-c (+) & Can-c (-) voltages under power for normal voltages... wich is (1.3 to 2.5V to can- and 2.4 to 3.5 for can+)

So far I didnt find anything out of specs, but since its an intermittent problem I was already expecting the readings to be all normal. But it makes it even more difficult to find... should I start dissasembling her dash and follow the wires for Canbus between CanStarLink behind the glovebox and the ABS module?

Its her daily driver and Id love to resolve this in a relatively short delay.

Also since its not safe to drive at the moment, Im considering to send the PCM to Hptuners and unlock it, so I can start to disable some of the codes one by one and see wich ones make it all act up.. I know this is not a fix, but It might make it safe to drive again until I find the real problem.

thanks for your help!

 

[LePogoQC]

I spent quite some time reading about canbus diagnostics in general and Id like your opinion on several point if anybody knows.

- wich modules in the can-c network have resistors?
- what kind resistance reading I should expect from a working canbus-c? (I'm reading 60ohm online from some sources, I'm only getting 40 ohm between can+ and can -)
- are there any other test I can perform on the canbus network with basic tools?

thanks

 

[LePogoQC]

Start of my diagnostic with only my multimeter, no acces to Witech..

Related ECUs : (ABS, PCM, CanSTAR-C link, ORC, BCM)

ABS CONTROL MODULE

• Checked both B+ for12v : all good
• Checked ground : all good
• Checked Can-c (+) at plug for normal state : 2.7V (normal range can+)
• Checked Can-c (–) at plug for normal state : 2.3V (normal range can –)
• Checked resistance between can+ and can- at abs module : 77.9KΩ (later was found normal comparing to another jeep)
• Checked resistance between can(+) and ground : Continuity (18MΩ to be exact on my cheap multimeter, not what I was expecting at all.)
• Checked resistance between can(-) and ground : Continuity (18MΩ to be exact on my cheap multimeter, not what I was expecting at all.)

CANSTAR C LINK

Average on canstarlink-c between + and – channel : 40.7Ω (should be 60Ω from my understanding of a high speed canbus ??)

Each module resistanche between Can+ and Can - :

*** Note that the numbers I'm using to refer to the connectors isnt nescessary pin number, I couldnt find the CanStarLink-C diagram but I started with C1 as 1 and went to the left until 10, then when to the other row (in front of it) and named the one to the right 11 and went to the left until 20***

1 yelow/lightbrown-white 124 Ω 60.4 Ω on other pinouts while disconnected (but there is a ground on this connector) Still need to try jumping ground with the rest disconnected

2 yellow/yellow-blue 26.8 K Ω still 40.7 Ω on other pinouts while disconected

3 yellow/yellow-brown 43.1 K Ω still 40.7 Ω on other pinouts while disconected

4 yellow/brown-white 26.7 K Ω still 40.7 Ω on other pinouts while disconected

5 yellow/lightbrown-white 26.8 K Ω still 40.7 Ω on other pinouts while disconected

6 yellow/blue-white 26.5 K Ω still 40.7 Ω on other pinouts while disconected

7 blank

8 blank

9 blank

10 blank

11 yellow/blue-white 77.9 KΩ still 40.7 Ω on other pinouts while disconected
- this one goes to ABS module, goes to open circuit when I disconnect ABS module
- When I short Can+ and Can- together at ABS connector and read resistance at CanStarlink connector I get 1.5 Ω wich is continuity for my multimeter (goes af far as 2Ω touching probes together) that means wiring is most likely good.
- maybe ABS module is bad? It also reads 77.8 KΩ between can+ and can- pinouts directly at the abs module. So its not faulty wiring that makes for the big resistance its the abs module itself.
- Also resistance between ground and canbus pins at ABS module is 18 MΩ

12 yellow-green/white-brown 127Ω 59.9 Ω while disconnected on other pinouts

13 (larger)yellow/violet-white 26.2 KΩ still 40.7Ω on other pinouts while disconnected

14 yellow/yellow-white 2.6 KΩ 41.2 Ω on other pinouts while disconected

15 yellow/grey 40.5 Ω still 40.7 Ω on other pinouts while disconected

16 blank

17 yellow/orange-white open circuit still 40.7 Ω on other pinouts while disconected

18 blank

19 yelloy/yellow-grey open circuit still 40.7 Ω on other pinouts while disconected

20 blank

CHECKED A FRIEND JLUR FOR SIMILAR RESULTS ??

resistance between can+ and can – on abs module : 77,9 KΩ (same result as my JL)

resistance between ground and can+ in abs module : open circuit, NO CONTACT AT ALL(my JL is 18MΩ, almost continuity)

resistance between ground and can- in abs module : open circuit, NO CONTACT AT ALL (my JL is 18MΩ, almost continuity)

Average resistance on the Canbus-C Network : 60Ω (my JL is at 40.7Ω, but 60Ω is a known good value on high speed canbus. Wich means something interferes on mine. I'm supposed to have 60Ω)

Therory is, My JLUR has a canbus short to ground inside the ABS module, the module keep working on its own, but when it comes to comminication to other modules via the PCM, it sometimes fail and interfere with lots of other modules over can-c

 

[tcsparks]

How is everyone's jeeps? I'm having this issue now. Did the things mentioned in this thread fix your issues? I'm losing hope... 1st time jeep owner and only had it for a 4 months, bought it used and I can't even enjoy it. Most of my time is spent trying to get this issue fixed.

 

[Predatorjl]

So, after a year of the problem and now close to a year with the fix I'm happy to say that with hours and hours of diagnosing and comparing issues others were having I have been able to fix the issue with my jeep.
I was able to replicate the x mas tree effect by moving the wires that plug into the Green Can Bus Star connector behind my glovebox. I checked all the wires and made sure all the plugs had a good connection and were seated which led me to the conclusion the Can Bus bank was bad. Upon initial inquiry the dealer told me that if i wanted the bank id have to buy the entire dash harness for the low low price of my left leg. I went to looking online and found a used on that matched my jeep. I switched out the Canbus and no issues for a year now.

Over a hundred people have messaged me asking if I had been able to fix the issue and through helping them diagnose their problem this fix helped 95% of them. I was just given the model number today that makes it possible to buy just the Can Bus, so you all don't have to buy the whole harness. It was always available, but no dealers really searched out for the part number. Now we have it, and that part number is 68321746AA.

I hope this fix can get many of you back on the road and prevent days and days at the dealership without them having a clue what the problem is. This has fixed over a hundred vehicles but keep in mind every vehicle us different. Yours may mimic the symptoms but have a different issue. This at least gives you a place to check for problems.

As always if anyone has a question dont hesitate to message me.

 

[Bob Burd]

Thanks for the update. Do you recall finding any fault with the old connector? I'm wondering if the act of unplugging all the inputs to it and reseating them in the new one had more to do with fixing your problem.

 

[Olsmokey18]

How is everyone's jeeps? I'm having this issue now. Did the things mentioned in this thread fix your issues? I'm losing hope... 1st time jeep owner and only had it for a 4 months, bought it used and I can't even enjoy it. Most of my time is spent trying to get this issue fixed.

Our 2018 JLU Sport S is a huge pile of junk. Also a 1st (and last time) Jeep owner. The dealerships are absolutely no help. Their technicians have no idea how to fix any electrical problem. I’ve been battling this nightmare for 6 months. Can’t even drive it.

 

[tcsparks]

Our 2018 JLU Sport S is a huge pile of junk. Also a 1st (and last time) Jeep owner. The dealerships are absolutely no help. Their technicians have no idea how to fix any electrical problem. I’ve been battling this nightmare for 6 months. Can’t even drive it.

I'm so sorry. Have you check the Star Connector (green box) behind the glove box? Just replace that or have a mechanic do it. It's a $45 part. I had a different mechanic fix it for me (not the dealership because they were clueless). It seemed to have fixed my problem. Thankfully no issues since the end of April. I hope you find a solution.

 

[Rico1111]

I purchased one to keep in my Jeep just in case this issue rears it's ugly head on my JLR. Also have an extra z fuse array.... you never know, they are cheap jeep insurance!

 

[hovanic]

Thank you Predatorjl ! you have saved me hours of time and countless $$$.

I took a chance with the parts shotgun approach and it appears to have payed off. My local Jeep dealers wanted upwards of $120 for the canbus star connector (68321746AA) I found it online from a dealer for 45 bucks + Shipping. Issue has not come back and its been about a week. While I was waiting I would clear the codes and maybe drive 45min - an hour and the dash would light up again.

 

[Joe's_Roxy]

Adding my 2018 JL Rubicon to the list of ones with issues...
Was at Moab this week and started throwing codes... on the Poison Spider. Got them cleared (pulled negative terminal off battery), didn't drive the jeep for a couple of days, and then took it down to Needles Park. Done the easy trail to Colorado River Overlook. One the way back to Moab... the Jeep threw codes and lost steering. Pulled the negative again and got back to the house we was staying at. This morning, we headed 120 miles to Grand Junction to the nearest Jeep dealership. They couldn't get to me so we rolled towards home. But, I did get the codes read (see below). We made it to Trinidad, CO today without issues. Only 800-900 miles to home. Hoping for the best. Just wanting to make sure this is the same others have seen and that the star connector is the right thing. Any thoughts? TIA!

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