Service 4WD light: C146313 C147B14 meaning

[Alexander K]

So my service 4WD light is flashing on and off irregularly (2020 Gladiator sport S). I have an ECRI and pulled those two code can’t find anything on what they are does anyone know what they mean?

C146313
C147B14

I have had this problem 2 years and as many have reported the dealership kinda just shoots in the dark to fix it. They replaced a couple things for me before it went away and took 3 weeks. I’m out of warranty now so want to try and understand what’s wrong and fix it myself or at least have direction if I go for service.

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[MT1]

Not an expert here, but did find this,

"C147B-14 Front Axle Disconnect Sensor-Circuit Short To Ground Or Open, C1463-13
Front Axle Disconnect Control-Circuit Open, Front Axle Disconnect Control-Circuit Short T0 Ground"
in this PDF,

https://static.nhtsa.gov/odi/tsbs/2020/MC-10223540-9999.pdf

If this were my Jeep, I would start with inspecting the wiring in those locations. The same codes are found in more search results, but for 4X4 Ram or Charger AWD.

Good luck!

Somewhere is a link to a zip from a member, with the wiring diagrams, just not having luck finding it right now...

 

[Alexander K]

Not an expert here, but did find this,

"C147B-14 Front Axle Disconnect Sensor-Circuit Short To Ground Or Open, C1463-13
Front Axle Disconnect Control-Circuit Open, Front Axle Disconnect Control-Circuit Short T0 Ground"
in this PDF,

https://static.nhtsa.gov/odi/tsbs/2020/MC-10223540-9999.pdf

If this were my Jeep, I would start with inspecting the wiring in those locations. The same codes are found in more search results, but for 4X4 Ram or Charger AWD.

Good luck!

Somewhere is a link to a zip from a member, with the wiring diagrams, just not having luck finding it right now...

Thank you so much this certainly gives me some good direction. FAD plug was the first place I checked in case it was dirty. I cleaned contacts and reassembled with dielectric grease, but the problem has persisted. Will give the wiring a thorough inspection and do some Multi-meter probing if I can find the wiring diagram.

 

[MT1]

Thank you so much this certainly gives me some good direction. FAD plug was the first place I checked in case it was dirty. I cleaned contacts and reassembled with dielectric grease, but the problem has persisted. Will give the wiring a thorough inspection and do some Multi-meter probing if I can find the wiring diagram.

Not a problem!

This is where I found the PDFs:

https://drive.google.com/drive/folders/10CFvo1WM9cYkL_Jq0brSSWWb3zUQuK7N

 

[Alexander K]

Not a problem!

This is where I found the PDFs:

https://drive.google.com/drive/folders/10CFvo1WM9cYkL_Jq0brSSWWb3zUQuK7N

This is quite the treasure trove! Defiantly good resources for anyone looking to trouble shoot things themself before going to the dealer and being out a rig for days.

 

[Commodus]

So my service 4WD light is flashing on and off irregularly (2020 Gladiator sport S). I have an ECRI and pulled those two code can’t find anything on what they are does anyone know what they mean?

C146313
C147B14

I have had this problem 2 years and as many have reported the dealership kinda just shoots in the dark to fix it. They replaced a couple things for me before it went away and took 3 weeks. I’m out of warranty now so want to try and understand what’s wrong and fix it myself or at least have direction if I go for service.

I had the same codes and the dealer traced it to the front locker harness. The factory ran the harness close to the catalytic converter that over time causes the wires to crisp under the wiring insulation

 

[Alexander K]

I had the same codes and the dealer traced it to the front locker harness. The factory ran the harness close to the catalytic converter that over time causes the wires to crisp under the wiring insulation

I have a sport so no factory locker harness routed mine myself up with the breather tube. Do you know if the front locker harness you are referring to is routed with the FAD wire? That seems to be the only electronic 4wd stuff the computer knows about so I'm not sure what else it would be though I have heard theres a switch on the top of the transfer case that sometimes goes bad?

 

[Alexander K]

UPDATE

It’s worse than I thought.
I finally got a chance ti poke around with a multi meter and check for the intermittent short. I was able to confirm a good ground at the connector then proved the rest of the connector for continuity to ground. Nothing; I couldn’t replicate the short seven with jostling the wire harness.

I inspected the wiring and found the Gnd wire bare and taped along side the harness. Huh that’s odd followed it all the way back to the bulk head going into the cab where it is spliced back into the wire harness.

This is atrocious and so shotty and I know that this must have been the “FIX” the dealer did years back when I had this same problem. I know it was them because the only people to touch this car have been me or the dealer. And I definitely didn’t do this.

Really disheartened to find my main wiring harness all chopped up and still no solution because as I said that ground wire appears to be working fine even if it’s janky.

Will do more probing and update if I find anything else.

 

[Commodus]

UPDATE

It’s worse than I thought.
I finally got a chance ti poke around with a multi meter and check for the intermittent short. I was able to confirm a good ground at the connector then proved the rest of the connector for continuity to ground. Nothing; I couldn’t replicate the short seven with jostling the wire harness.

I inspected the wiring and found the Gnd wire bare and taped along side the harness. Huh that’s odd followed it all the way back to the bulk head going into the cab where it is spliced back into the wire harness.

This is atrocious and so shotty and I know that this must have been the “FIX” the dealer did years back when I had this same problem. I know it was them because the only people to touch this car have been me or the dealer. And I definitely didn’t do this.

Really disheartened to find my main wiring harness all chopped up and still no solution because as I said that ground wire appears to be working fine even if it’s janky.

Will do more probing and update if I find anything else.

You can purchase the locker wiring harness from the dealer which is what I had to do and never had any previous repairs performed, which is what they should have done in the first place

 

[Alexander K]

You can purchase the locker wiring harness from the dealer which is what I had to do and never had any previous repairs performed, which is what they should have done in the first place

Were you able to buy the FAD harness or the factory locker harness?
This is for the FAD and appears to be a part of the main chasis harness. While I could replace it, it looks is super involved and probably not accessible without cab off not to mention its 500...

 

[Commodus]

Were you able to buy the FAD harness or the factory locker harness?
This is for the FAD and appears to be a part of the main chasis harness. While I could replace it, it looks is super involved and probably not accessible without cab off not to mention its 500...

It was the front locker harness that I had a friend that works at the dealership replace it He said he has seen a few

 

[Alexander K]

Update: Decided to wire up the fad for manual control. Used this thread as a guide for the controls:
https://www.jlwranglerforums.com/forum/threads/how-to-manually-control-the-fad.42710/page-3
Took me a while to figure out that for whatever reason on my gladiator pin 2 and 3 are swapped so I needed to ground Pin 2 to engage NOT pin 3. with that done its actuating.

I am using the aliexpress connectors discussed here they seem to work great and the pin numbering matches the OEM connector. Color scheme for me with these connectors seems to be: Green-Ground, White-12v ignition, Black-Signal.

I did a teardown of the FAD Actuator and learned something rather interesting. It isn't actually a spring that keeps the collar in the open position its the motor. It is driven using a worm grear to make the whole mechanism not back-driveable thus whatever position the motor is in the fad stays in thanks to the spring coupling the collar to the motor gear. It also remains locked in this position regardless of if there's power to the unit or not. This means you can't simply tie the control pin to ground and then give it 12v to lock it because it will just stay in locked position when 12v is removed. This may also cause the sensors to get out of alignment and put the motor into a stall state trying to correct and drawing as much current as it can. Be sure to use a current limiting supply if you're gonna play around with this or you may burn it out. Attached are some pictures of the internals. Best bet IMO to wire this up is give it Gnd and 12v ign then use a switch to short the control to Gnd when you want 4wd; you can do it through a relay or just use a switch it's not a high current signal.

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