Differential Lock Help on LR3

[NJoverland]

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.

 

[Marine_Diesel]

If you’re still stuck.

Remove the diff motor and get it on the workbench table. Use some mole grips to free up the motor. It will just be stuck.

however when replacing, there is no gasket so make sure the mating faces are perfectly clean before applying a continuous bead of sealant to the face and progressively tightening the 4 bolts. Then leave until next day to test.

 

[Red90]

Check your brake light bulbs.....

 

[NJoverland]

If you’re still stuck.

Remove the diff motor and get it on the workbench table. Use some mole grips to free up the motor. It will just be stuck.

however when replacing, there is no gasket so make sure the mating faces are perfectly clean before applying a continuous bead of sealant to the face and progressively tightening the 4 bolts. Then leave until next day to test.

Thanks! It's not stuck. Totally drivable, just won't engage.

Check your brake light bulbs.....

I've read this and I don't buy it. It's got specific codes for the diff lock motor. I've read stop light switch, which I changed, battery, etc. I just don't buy the brake lights will throw codes this specific.

 

[BorellaFamilyAdventures]

I had this same issue. Turned out the motor was fine and the clutches in the diff were worn enough to not be able to engage and cause the fault. I ended up ordering a new/refurbished unit from Texas and all was fine afterwords.

 

[Victory_Overland]

I've read this and I don't buy it. It's got specific codes for the diff lock motor. I've read stop light switch, which I changed, battery, etc. I just don't buy the brake lights will throw codes this specific.
[/QUOTE]

Brake lights and brake light switches will give you every code that is critical for driveability; TC, Trans, Susp Fault, Engine Purge, you name it and disengage all aspects of the Special Programs.

You can quote me on the above statement anytime you want! Start simple brother, start simple! When I first got into my LR3 (L319) I chased a TC Fault for days; one code and no Special Programs. Three months ago I finally got the broken wire in the kick panel; this time it was Trans Fault and Steering Sensor. I fixed the single splice wire, rebooted the truck and perfecto!

@Red90 is spot on with lights and switch check as your first go-to.

Not saying it's your issue but I wouldn't rule out simple first; off my soapbox.