2020 Wrangler Rubicon - electrical problems

[LA_Mike]

Hi
Just purchased a used 2020 Wrangler Rubicon with 68,000 miles on it. On the drive home from the dealer the insanity started already ...

Symptoms: Power steering fails, Service Shifter message, Stability Control Module warning, gauges are possessed (up and down), sometimes wipers turn on as well.
Turning car OFF and ON makes it work normal for an undefined time. Does not seem to be a module/sensor problem but an intermittent wiring issue.

What was done so far:
Brought it back to the dealer - stayed there for two weeks - no failure found - hundred point inspection (right!).
Got it back and symptoms returned just like before. Decided to do my own "fixing".
Eliminated the Aux battery (fuse and negative cable), re-seated all fuses in the box, checked all connectors under car (I hope?). Checked the green connectors under the glove box.
Read the codes with JScan software and there are many, many codes, but all related to loss of CAN-bus connection and communication loss between modules.
I am kind of frustrated at this time. Did anybody experience something similar and was able to fix it somehow? Any pointers welcome ...

Mike

Sponsored

 

[mjg4xe]

Hey Mike - I have read about some of these symptoms for people who need a new 12v battery. The batteries that come with the Wranglers stink - and sometimes they will pass the dealer "checks" but still not be able to handle a load. Might be worth trying to replace the battery. In addition, do you have any other aftermarket electrical-related accessories? (or signs they were on the Jeep previously?). Best of luck.

 

[gahammerle]

A lot of those symptoms match the problem I had and replacing the green canbus connection block behind the glove box solved things for me (as well as for lots of others on this forum).

 

[Jeep Wick]

Hi
Just purchased a used 2020 Wrangler Rubicon with 68,000 miles on it. On the drive home from the dealer the insanity started already ...

Symptoms: Power steering fails, Service Shifter message, Stability Control Module warning, gauges are possessed (up and down), sometimes wipers turn on as well.
Turning car OFF and ON makes it work normal for an undefined time. Does not seem to be a module/sensor problem but an intermittent wiring issue.

What was done so far:
Brought it back to the dealer - stayed there for two weeks - no failure found - hundred point inspection (right!).
Got it back and symptoms returned just like before. Decided to do my own "fixing".
Eliminated the Aux battery (fuse and negative cable), re-seated all fuses in the box, checked all connectors under car (I hope?). Checked the green connectors under the glove box.
Read the codes with JScan software and there are many, many codes, but all related to loss of CAN-bus connection and communication loss between modules.
I am kind of frustrated at this time. Did anybody experience something similar and was able to fix it somehow? Any pointers welcome ...

Mike

There is another green canbus near the back seat. You can find factory wiring diagrams on the forum. I've read where someone had a bad harness at the sway bar disconnect that also caused this. Keep looking around, you will probably figure this out before the dealer.

 

[tomk62]

Hey Mike - I have read about some of these symptoms for people who need a new 12v battery. The batteries that come with the Wranglers stink - and sometimes they will pass the dealer "checks" but still not be able to handle a load. Might be worth trying to replace the battery. In addition, do you have any other aftermarket electrical-related accessories? (or signs they were on the Jeep previously?). Best of luck.

@LA_Mike this is the most likely cause.

 

[LA_Mike]

Hey Mike - I have read about some of these symptoms for people who need a new 12v battery. The batteries that come with the Wranglers stink - and sometimes they will pass the dealer "checks" but still not be able to handle a load. Might be worth trying to replace the battery. In addition, do you have any other aftermarket electrical-related accessories? (or signs they were on the Jeep previously?). Best of luck.

Thank you for your reply - I will take a look at the main battery (only one connected now) and its date and also check it with a load tester. Will report back ...
Somewhere I read that people buy a slightly bigger battery when replacing the factory piece - apparently there are two sizes that fit ...

 

[LA_Mike]

A lot of those symptoms match the problem I had and replacing the green canbus connection block behind the glove box solved things for me (as well as for lots of others on this forum).

Thank you for your reply. Yes, I have seen people mentioning this. I had looked at it before, but maybe it's something that cannot be seen ...
I have ordered a new green connector from eBay and will transfer cables one by one and report back ...
Other posts I had read somewhere mentioned that compromised GND connections are causing quite a few problems with these vehicles as well.

 

[gahammerle]

Thank you for your reply. Yes, I have seen people mentioning this. I had looked at it before, but maybe it's something that cannot be seen ...
I have ordered a new green connector from eBay and will transfer cables one by one and report back ...
Other posts I had read somewhere mentioned that compromised GND connections are causing quite a few problems with these vehicles as well.

Yeah, I visually inspected my old one and could not see anything wrong with it, but we've gone 9 months and 10k miles without the issue reappearing.

 

[mjg4xe]

Thank you for your reply - I will take a look at the main battery (only one connected now) and its date and also check it with a load tester. Will report back ...
Somewhere I read that people buy a slightly bigger battery when replacing the factory piece - apparently there are two sizes that fit ...

If you replace, make sure to do the aux battery with it. People sometimes still have issues if they don’t do both together. If you want something better than the OEM one, Odyssey is one often mentioned on here. I don’t think you’ll need a bigger one unless you have other accessories wired to it (winch, lights, steps, etc)

 

[Rhinebeck01]

Thank you for your reply - I will take a look at the main battery (only one connected now) and its date and also check it with a load tester. Will report back ...
Somewhere I read that people buy a slightly bigger battery when replacing the factory piece - apparently there are two sizes that fit ...

Do your homework before you buy new batteries..

Regardless of whether your JL left the factory with an H6 or H7, Main.... if you are going to buy a new Main battery you will want to go with an H7. You would be very foolish not to go with an H7.
https://www.jlwranglerforums.com/forum/threads/??-main-battery-replacement-talk-jl-jt-?.100534/

 

[LA_Mike]

Yeah, I visually inspected my old one and could not see anything wrong with it, but we've gone 9 months and 10k miles without the issue reappearing.

Sounds promising - I will let you know how it went

 

[LA_Mike]

If you replace, make sure to do the aux battery with it. People sometimes still have issues if they don’t do both together. If you want something better than the OEM one, Odyssey is one often mentioned on here. I don’t think you’ll need a bigger one unless you have other accessories wired to it (winch, lights, steps, etc)

I took the Aux battery out of the equation for now. Fuse 47 and ground cable removed. Never use start/stop anyway. Just to simplify things.

 

[geem03]

My issue was the power steering pump that was shorted out and giving the same symptoms that you are saying. The pump has two electrical connectors. They disconnected the bottom one to isolate my issue. It stopped all symptoms except the loss of power steering.
Maybe something you could try.
I changed the pump and have been symptom free since then. I just get an occasional ghost chime not associated with any errors or dummy lights. IDK!

 

[LA_Mike]

My issue was the power steering pump that was shorted out and giving the same symptoms that you are saying. The pump has two electrical connectors. They disconnected the bottom one to isolate my issue. It stopped all symptoms except the loss of power steering.
Maybe something you could try.
I changed the pump and have been symptom free since then. I just get an occasional ghost chime not associated with any errors or dummy lights. IDK!

Thanks. Another thing to check. It always starts with power steering failing before other messages appear ...

 

[richk225]

FYI Rubitrux has electric power steering pumps for sale

https://www.rubitrux.com/jeep-wrangler-jl-3-6l-factory-oe-mopar-power-steering-pump-68247930.html

Sponsored