Service 4WD light, code C147B-92 and P032F

[Shibbyjeep]

After driving 5.5 hours back from Stoney Lonesome this weekend I got home, unloaded the truck and trailer and got back in the truck to take the camp trailer back to my work(I store it there for now). As soon as I started the truck I got a ding and the "Service 4WD" light came on. I drove to work, unloaded the trailer and proceeded to put it into 4Hi and disconnect the swaybar and both seemed to work and no extra dings. Being late I had to go and pick up my son so I didnt have time to engage 4Lo and lockers. This morning I used the Tazer to tell me what codes the truck had. First code is a PCM code P032F which via a quick google search says its " Combustion Engine Producing Insufficient Torque" the second code was C147B-92 which the google machine says its " Front Axle Disconnect (FAD) sensor performance or incorrect operation problem ". I jumped under the truck briefly to see if the FAD was damaged or anything that I could quickly see and thanks to my Metalcloak FAD skid everything looks unstruck. The plug for the FAD does seem a little loose so I do wonder if too much articulation may have strained it and made to where it doesnt have a great connection.

I searched the CEL code on the forum and nothing about the C147 code. Wondering if anyone else has seen this code or either code and what you had to do to correct it?

Thanks in advance for any suggestions!

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[JTdiRtyD]

Regarding the FAD:

https://static.nhtsa.gov/odi/tsbs/2020/MC-10177485-9999.pdf

I had this happen no shit the day I drove it home from the dealer and parked in my driveway. Left to go to town an hour later and the code popped up. The dealer "fixed it", but 6 months later it started happening again but only when it's wet out, so my guess is I have some wires becoming exposed again and when it's wet and water starts building up on them they start to short.

 

[DylanM]

The C147B-92 code will kick out in two situations: either when the FAD is commanded to engage but the position sensor indicates it is not doing so, or when the FAD disengagement retry count reaches 100 over 5 key cycles (ie, the truck thinks the FAD is stuck engaged).

In addition to giving the FAD wiring a good lookover and a try at cleaning and reseating the FAD wiring connector, I would jack up just the right front tire and see if it spins when the transfer case is shifted into 2HI and again in 4HI (be sure to turn the ignition on when shifting to 4HI so the FAD can work). If the wheel doesn't spin in 2HI then the FAD is stuck engaged. If the wheel spins in both 2HI and 4HI then the FAD isn't engaging. If the wheel spins in 2HI but not in 4HI then the FAD is working properly, it's just the position sensor or its wiring that is causing an incorrect signal.

 

[Shibbyjeep]

The C147B-92 code will kick out in two situations: either when the FAD is commanded to engage but the position sensor indicates it is not doing so, or when the FAD disengagement retry count reaches 100 over 5 key cycles (ie, the truck thinks the FAD is stuck engaged).

In addition to giving the FAD wiring a good lookover and a try at cleaning and reseating the FAD wiring connector, I would jack up just the right front tire and see if it spins when the transfer case is shifted into 2HI and again in 4HI (be sure to turn the ignition on when shifting to 4HI so the FAD can work). If the wheel doesn't spin in 2HI then the FAD is stuck engaged. If the wheel spins in both 2HI and 4HI then the FAD isn't engaging. If the wheel spins in 2HI but not in 4HI then the FAD is working properly, it's just the position sensor or its wiring that is causing an incorrect signal.

I will def try this when I get to look at it tomorrow.

I had read that the Serv 4WD light could limit offroad functions, but at lunch I checked and 4Hi, 4Lo, swaybar disconnect, and both front and rear lockers all seem to be working(Atleast according to the dash, I will check actualy front FAD function tomorrow). So at least I dont seem to have any limitations to the system at the moment.

 

[JTdiRtyD]

I will def try this when I get to look at it tomorrow.

I had read that the Serv 4WD light could limit offroad functions, but at lunch I checked and 4Hi, 4Lo, swaybar disconnect, and both front and rear lockers all seem to be working(Atleast according to the dash, I will check actualy front FAD function tomorrow). So at least I dont seem to have any limitations to the system at the moment.

My understanding is it will only affect function if the light is active and being displayed. My systems all function just fine in Utah even though my light comes and goes (as long as the light is off).

If your light is intermittent and comes and goes (like mine did), it's likely a short somewhere.

 

[Shibbyjeep]

My understanding is it will only affect function if the light is active and being displayed. My systems all function just fine in Utah even though my light comes and goes (as long as the light is off).

If your light is intermittent and comes and goes (like mine did), it's likely a short somewhere.

As soon as I put it in drive it comes on, but not in reverse. I had to back out at Chickfila at lunch and it didnt come on until I put it in drive.

 

[JTdiRtyD]

As soon as I put it in drive it comes on, but not in reverse. I had to back out at Chickfila at lunch and it didnt come on until I put it in drive.

That to me sounds like either a loose connector or more than likely you have a break at one of those points in the bulletin I posted. So it would make sense that everything works fine when the conditions are right and the wire isn't moved, but once that wire gets moved then you get the light.

 

[WILDHOBO]

I will def try this when I get to look at it tomorrow.

I had read that the Serv 4WD light could limit offroad functions, but at lunch I checked and 4Hi, 4Lo, swaybar disconnect, and both front and rear lockers all seem to be working(Atleast according to the dash, I will check actualy front FAD function tomorrow). So at least I dont seem to have any limitations to the system at the moment.

Makes it sound minor then. I’d disconnect the fad wiring, clean it with contact cleaner, then add dielectric grease and reconnect. If it continues, maybe the sensor needs to be checked as others smarter than me recommended.

 

[WILDHOBO]

My understanding is it will only affect function if the light is active and being displayed. My systems all function just fine in Utah even though my light comes and goes (as long as the light is off).

If your light is intermittent and comes and goes (like mine did), it's likely a short somewhere.

Jeeps always function perfectly in Utah. But when you cross that state line…

 

[Shibbyjeep]

Well the truck was just fooling me that 4WD was engaging. Found out halfway through the day on Saturday at Windrock. So good news, I can run super muddy trails in my truck at Windrock(blues) and not need 4WD for 98% of it. Bad news is there were 2 hills too steep for me to make it up on my own in 2wd w/locker engaged. So had to winch twice. Now to take it to someone more qualified than me to figure out the issue...

 

[WILDHOBO]

Well the truck was just fooling me that 4WD was engaging. Found out halfway through the day on Saturday at Windrock. So good news, I can run super muddy trails in my truck at Windrock(blues) and not need 4WD for 98% of it. Bad news is there were 2 hills too steep for me to make it up on my own in 2wd w/locker engaged. So had to winch twice. Now to take it to someone more qualified than me to figure out the issue...

That’s annoying. Sorry to hear. But when it’s fixed, you’ll know more about your Jeep than before.

 

[DylanM]

Well the truck was just fooling me that 4WD was engaging. Found out halfway through the day on Saturday at Windrock. So good news, I can run super muddy trails in my truck at Windrock(blues) and not need 4WD for 98% of it. Bad news is there were 2 hills too steep for me to make it up on my own in 2wd w/locker engaged. So had to winch twice. Now to take it to someone more qualified than me to figure out the issue...

So I take it that you didn't verify the FAD was working first, or did the FAD stop working at some point while at Windrock?

 

[Shibbyjeep]

FAD module is cooked. Going to figure out what I am going to do from here.

 

[DylanM]

That doesn't help clear things up. Did you actually check the FAD function as recommended earlier, and if so, what were the results? Did you try to clean and reseat the FAD wiring connector?

Could you clarify how/why the "FAD module is cooked" and how that conclusion was reached?

Answering these questions honestly and as completely as possible can help others in the future that may have similar problems.

 

[Shibbyjeep]

That doesn't help clear things up. Did you actually check the FAD function as recommended earlier, and if so, what were the results? Did you try to clean and reseat the FAD wiring connector?

Could you clarify how/why the "FAD module is cooked" and how that conclusion was reached?

Answering these questions honestly and as completely as possible can help others in the future that may have similar problems.

Yes I tried pulling and cleaning the FAD connector. Also checked to ensure it wasn't pulling any pins out of the connector.

The FAD can be operated manually from a connected scan tool. It will engage and disengage. But will not function on its own when putting the truck into 4WD HI. The FAD position sensor inside the module is whats not reporting properly. IE its cooked.

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