I've got the HDC fault and these codes:

• P080A-00 (7F) Clutch position is not learnt
  ( on 05-07-2022 18:19:23 at 154352 mi )
• P186D-00 (7F) Clutch actuator stuck
  ( on 05-07-2022 18:19:23 at 154352 mi )

ABS / DSC / Brake light is on. I went into GAP and set the vehicle to locking differential : not equipped. Cleared faults (these didn't budge). The TSB from Land Rover is nearly identical to my issues and pointing to a differential lock motor. I'm reluctant to buy one because theoretically the codes shouldn't come on if the clutch is stuck if the vehicle isn't equipped w/ a diff lock. I want the locker, but more important to me is special programs which are inoperable right now. Diff fluid is brand new with OEM fluid from Atlantic British and the battery is a brand new Interstate AGM with all normal voltages (14.4v). I'm stuck now.

 

If you edited the CFF, which reboots the truck, then cleared the codes but had no shutdown time between - well they will come back as I described in another thread. I think this is because vehicle dynamics itself still believes the locker is installed and needs to reset/sleep/shutdown for a while/whatever. You need to let the truck reset after changing the CFF to not have the locker. You dont need to pull the battery, but the system needs to completely sleep or idle out. As for the diff, ignoring the locker issue will of course destroy the locking diff clutch pack if the clutch pack is engaged even a little in the stuck position.

 

Alright, well it sits in the garage on weekdays so I guess on Friday when I take it out we'll see what happens. Thanks for the info. You are the only one who replied across 3 forums and 3 FB groups.

 

That's probably because Dakota is one of the most knowledgeable LR3 owners across 3 forums and 3 FB groups; don't take it personal or as an indication that people didn't want to help you.

 

So, it's been more than 2 months researching this issue. I finally broke down and ordered the diff lock actuator yesterday morning. I decided to do a re calibration with the gap tool one last time. It suceeded as always but the lights didn't go out. I take a ride later, and the lights are out. I thought it had to be the sun hitting the cluster and I just couldn't see them. Well, no. They are out and everything is working. I took it out to s local spot to lift the wheel and get the lockers to kick in which they did. Now I have to cancel my order, but that's a good thing. For this issue I've

1. Replaced brake stop switch. Lights went out for one drive and came right back.
2. Changed diff fluid. Nothing, but the diff fluid was nasty so good thing I changed it.
3. Re calibrated with the gap tool. Took me three tries over 2 mos but seems that finally worked.
4. Tried telling the car it didn't have a locker. Lights stayed on.

Well, GAP iid just paid for itself 10 fold.

 

Did you at least upgrade the rear diff software? Also I bet it comes back, once the actuator is damaged then it gets worse and worse. I hope not, but your fix may be temporary. If you take it off-road and here any loud "snaps/clunks" of metal form the back, then you know the actuator it taking out the diff as it goes past its set points.

 

It's up to date already.

 

Hi guys,

im having a similar issue and I’m trying to figure out where to start. When I shut off the vehicle I heard a loud “clunk” in the rear. I’ve got the locking rear diff. I also just had the diff fixed. A rodent chewed a wire for the temp gauge for the rear diff. I got that fixed and this “clunk”, the lights and codes randomly show… while the “clunk” has been a regular sound as of lately. I have the gap tool. I just reached out to gap to purchase an update for the rear diff, transmission and transfer case. Haven’t heard back yet. Is this the right move? I’ve read that updating the transmission if it hasn’t been serviced or the TCCM hasn’t been replaced can be more problematic.

ideas, thoughts?

 

If you're hearing a clunk it sounds like a mechanical issue, not software. I had no noises. I calibrated my rear diff with gap and the lights went away. Everything seems to be working fine.

 

The clunk is a symptom of software issue when the software has not been updated and damage starts to occur to the locking actuator. Sometimes software can stop the clunk before “actuator stuck” occurs, at which point is best to update the software and replace with a new ORM actuator. A stuck actuator can burn up the rear diff clutches.