Thread: help! Transmission / HDC fault

Originally Posted by josh.huber

Hey Pete,

When I did a upgrade over gap. I just paid for ecu upgrades and emailed them the names of what I wanted to upgrade. They put the files in your account. You put them on the tool and upload then.

If your indie has the tool I believe they can do this for free as they pay for annual subscription. They will obviously charge you for it as the annual fee isn't cheap. Reading the faults. Clutch stuck and position failure. I would start there. If the clutch pack is seized or the actuator failed the excess current draw would explain the Cascade of errors. Should be easy to remove, clean and test the actuator

What did that cost for that option? I did not see it but might have missed when I looked earlier.

I'm hoping the diff itself ie clutches are not the cause as they will be a lot more expensive than the actuator. I would assume only real test you could do would be a resistance check to see if its short or open cct,or connect to 12v to to see if it drives the shaft.

Originally Posted by PeterOZ

What did that cost for that option? I did not see it but might have missed when I looked earlier.

I'm hoping the diff itself ie clutches are not the cause as they will be a lot more expensive than the actuator. I would assume only real test you could do would be a resistance check to see if its short or open cct,or connect to 12v to to see if it drives the shaft.

The free upgrades option is gap IID Pro. It's an annual fee. Can't remember the price.. No good for a single user like me. With the BT option we pay per upgrade. I wouldn't feel that an upgrade would fix a hard fault.. Especially in a D3 should have been sorted well before now

I would pull the actuator and see what it does out side of the diff.. I havnt tried this before so take that advice carefully. My laptop with the manual is flat so I can't look it up.. But I would not try to drive it with any other source incase you burn it by accident.

Though reading some other threads suggest connecting only a 9v battery to prevent any damage to the motor. Across connectors C2168-1 & 10.

I'll see if I can get it up on the stands and do some measurements. Solenoid could be a suspect area as I have read of those going short cct on the transfer case.

rear diff schematic snip.jpg

Found this very useful thread on the US LR forum, hope it is ok to post it here.

Linky

Originally Posted by josh.huber

The free upgrades option is gap IID Pro. It's an annual fee. Can't remember the price.. No good for a single user like me. With the BT option we pay per upgrade. I wouldn't feel that an upgrade would fix a hard fault.. Especially in a D3 should have been sorted well before now

I would pull the actuator and see what it does out side of the diff.. I havnt tried this before so take that advice carefully. My laptop with the manual is flat so I can't look it up.. But I would not try to drive it with any other source incase you burn it by accident.

T

here is a TB out advising that when the actuator is replaced you need to get the updated firm wear patch.

LTB00228NAS3

SECTION: 205
'Transmission Fault' Displayed with DTC P186D Stored
AFFECTED VEHICLE RANGE:
LR3 (LA) VIN: 5A000360 - 9A513325
Model Year: 2005 - 2009
Range Rover Sport (LS) VIN: 6A900129 - 7A999999
7A100001 - 9A215620
Model Year: 2006 - 2009
Range Rover (LM) VIN: 7A239036 - AA307231
Model Year: 2007 - 2010
CONDITION SUMMARY:
Situation: The driver warning message 'Transmission Fault Stop Safely' may be displayed in the instrument
cluster message center, Diagnostic Trouble Code (DTC) P186D, and possibly P080A / P0806, may be stored
in the electronic rear differential control module, and the Dynamic Suspension may lower. These issues may
be caused by the Electronic Torque Managed (ETM) rear differential motor being energized while the motor
brake is still partially engaged, resulting in mechanical wear of the motor assembly which may lead to a stuck
actuator and DTC P186D.
NOTE: After the new differential motor has been installed, it is imperative that the new software is
downloaded to the Rear differential control module. Failure to carry out this instruction will result in
a future repeat repair. Once the new software has been downloaded, the software stored in the Rear
differential control module should show 7H42-4C045-A(D) or a higher alphabetical character for
vehicles pre-2010MY and 9W83-4C045-A(D) or a higher alphabetical character for vehicles 2010MYonwards.
NOTE: To complete the repair the new software must be downloaded and the on demand self test
(ODST) concluded. SDD will run the ODST automatically as part of the software download to the Rear
differential control module, follow all on screen instructions to ensure the ODST is successfully
completed. The ODST configures the Rear differential control module to ensure that it knows where
the clutch biting point is internal to the axle assembly. After the ODST has completed successfully,
clear DTCs and perform an ignition cycle; read DTCs and confirm none are present. If DTCs remain,
follow normal SDD diagnostic procedures.
Action: In the event of a customer concern of the above, refer to the Repair Procedure outlined below to
replace the rear differential locking motor assembly and update the Rear differential control module software.
PARTS:
LR011036 ................Rear differential motor - LR3, Range Rover Sport Qty: 1
LR030848 ................Rear differential motor - Range Rover Qty: 1
TOOLS:
IDS with latest IDS DVD; software first available on IDS-DVD125_V5.03 and Calibration File 66
Land Rover-approved Midtronics Vehicle Power Supply
Refer to Workshop Manual for any other required special tools

for sh its and giggles I decided to re-run the rear diff self test and the TC calibration routines again.

I managed to clear all the fault codes! Went for a 30 min drive up the highway through 100 & 80 / 60 km zones, stopped at teh shops for some moo juice and back home. About an 20km round trip and no issues and no fault codes thrown up.

I certainly do not think the real problem is fixed but at least I can get to work tomorrow hopefully.

I do suspect the culprit is the actuator either the motor or within its housing, something sticking, making the motor bind up a bit and pull excessive current causing it to throw up the errors.

I'll monitor it see what happens.

Here we go team,

Bought myself a toy - probably went with the wrong type of Land Rover to enjoy.....2005 Discovery 3 TDV6 HSE.

Had the car for a few months.... enjoying it as a change from my Disco 5 (2018) - but recently we started getting a transmission fault (intermittently)..

Now we have a brigade of dash lights:
HDC Fault
Transmission Fault
Airbag suspension lights
Low range flashing on the dash (and both ranges flashing on the lever)
No special programs available warning
Park brake losing it's mind if I'm in Park and it's not engaged...

Today I purchased a Bosch battery from Brighton LR - was hoping it would resolve the issue/s but unfortunately not.
Next step - purchased the updated transfer case module (mine was held together with tape) and having it installed/programmed to the vehicle next week.

Let's see what happens from there... will keep you posted and probably will hit up the forum if we still have issues (can't imagine having Brighton LR do all the work will bring my wallet much joy).

:-)