Hi my lr3 has christmas tree hdc, park brake and suspension lowering with clutch actuator stuck code P186D-00. We have replaced the brake light switch, put new o rings on the suspension valve block, and also replaced the locking motor on the rear locking diff. We are still getting this error every one in a while we press on the brakes. I am so lost and needing advise on what it could be. I was reading that it could be brake light bulbs not being factory, wheel speed sensors, TCM, and even reprogramming the locking motor?? What can it be. Please help.

 

The P186D-00 code could be the clutch packs in the diff itself, unfortunately. I'm not 100 on that, but I think the locking motor causes it (so it's good that you replaced it) but if it is too late, the clutch can be damaged. I know that I've had to replace both....but that was also the dealer advising. We know they love to upsell and generally just do wholesale R&Rs so maybe there is an alternative. At least they got the Factory to pay for it, and it didn't kill my wallet.

For the Christmas Tree....I'd suspect your battery. Could also be a steering angle sensor; how is your alignment?

 

If indeed battery - could it also be causing a "false" P186D-00 due to low-voltage?

When my battery was dying, I got a Parking Brake Failure Low Voltage "false" error.
New battery fixed all - funny how sensitive these are to low voltage.

 

1. I'm not sure that fault is one of the typical ones you'd get for low voltage.
2. If the clutches are bad, you'll get a "clunk" in certain conditions. Try driving around in Rock Crawl, maybe in reverse through a turn. Something to put a little bit of load on the drivetrain....see if you can't hear it.

 

P186D-00 is actuator only related, there is a position sensor and when no change in position is detected it assumed the actuator is not working/stuck.

 

P186D-00 is the ONLY code? You clearly have a Rover-centric reader. That code would not cause the faults. Either the brake switch is not Ford/OEM or you have a brake light out where a broken filament is connecting with another which causes a weird short. Finally learned why brake lamps can cause faults. Proper lamps have vertical elements that generally can not brake and fall into its neighbor.

Oh, that code would not cause any of those faults. I lived with it for quite some time before replacing the actuator - which oddly continued producing that codes but at a lesser rate until one day it never came back.

 

Thank you for all your suggestions. So I am ordering new brake light bulbs now to see if that doesn't have anything to do with. It weird when it happens all my husband has to do is shut down the car and turn it back on and the Christmas tree is cleared. What is an OEM brake light switch. I can't remember where we bought outs from. When we looked at the bulls in the back they work but the bulbs were corroded around it. could it be the tcm or speed sensors? I haven't check the steering wheel sensor however we just got an alignment on it from Range Rover and the alignment is fine.

 

Not sure who makes the OEM part....but I thought it was a Ford part. If all your brake lights are intact, then I don't think the bulbs are the issue; still a good idea to have legit ones on hand though. Again I'd also be looking at the battery, if the Christmas Tree is only on startup.

 

Ford (Blue/White, stamped FoMoCo): SW6572