I'm pretty new to this forum so nervous about going over old ground but trust me I have searched high and low within the existing topics for a solution to my problem but to no avail.
I have recently acquired a 2009 Discovery (L319) TDV6 Auto. When driving after about 30 mins (once the car is warm) I am getting the following gambit of warnings with a drop of the suspension to the lower limits.
- "Suspension lowered"
- "Transmission fault limited gears available"
- "Park brake fault"
- "HDC fault system not available"
- "Transmission range change not available"
- Speedo drops to zero with no odometer count up.
I can get the above messages to clear by pulling over and doing 2-3 power recycles by moving key to position 0 then 2. All warning lights disappear and the car is good for another 10-20 minutes before I get a recurrence. Sometimes it might not occur for another 40 minutes. I have been trying to capture the exact conditions in which the fault arises and I would say it's most common when either climbing a hill or cresting a hill. I have an iCarSoft v2.0 which has allowed me to view/clear the following codes.
- U0122 (Lost comms with VDCM)
- U0402 (Invalid data from TCM)
- U0416 (Invalid data from VDCM)
- U0403 (Invalid data from TCCM)
- U2005 (Vehicle Speed)
- C1A00 (Control Module)
- C1A99 (Pressure sensor circuit)
I know it is likely down to an electrical/sensor issue leading to the system throwing the proverbial teddies but it's proving very difficult to find out what the issue(s) is (are).
I've replaced the brake switch.
I've replaced all of the rear bulbs.
I've fully charged the battery and it seems to be good cold (12.7v) and under alternator (13.9-14.2).
What I do know about the car is that it was running without issue for the previous owner but once he sold it to a garage they, for some reason, fitted a new air suspension compressor (Hitachi) shortly before I bought it. I am therefore starting to think more and more that the fault is suspension related following this work.
When looking at live data I notice a few things if it helps...
1. The ride heights are quite different when parked on a relatively flat surface.
2. At standstill the lateral acceleration is reading 0.04G but the longitudinal acceleration is 65.52G. Surely the latter is in error? If I drive the car it moves between 0G and 65.52G as a datum and every so often flicks to a more sensible dynamic reading such as 0.27G under light braking.
3. Whilst at standstill the air compressor temperature can often get to 130 degrees + as if it is running longer than it should do with no actual demands for a change in suspension settings.
4. Air suspension gallery pressure seems healthy at circa 800-1400kPa.
5. My wife said when sat behind me on the road the car appeared "wonky".
Once the car gets up to full temperature the fault can also occur at standstill which once again makes me think it's related to the suspension.
Over to the experts! I'm tearing my hair out.
Thanks in advance,
Jamie
24th Jan 2021 9:13 pm
TyphoonDisco
Member Since: 18 Jan 2021
Location: Morpeth
Posts: 102
In addition to the above,
The steering wheel sits approx 10 degrees to the right when driving straight. This appears to have been calibrated as the SASM live data shows 0 degrees steering angle with the wheel slightly offset. However, the VDCM live data shows a steering angle of 780 degrees when in the same position.
I'm not sure this relates to the major fault because the previous owner reported no issues and the steering has not been adjusted since, only the suspension compressor.
Please help!
25th Jan 2021 3:40 pm
TyphoonDisco
Member Since: 18 Jan 2021
Location: Morpeth
Posts: 102
Okay, in the absence of any advice so far I will offer some more observations.
Whilst the wife was driving I was monitoring live data from the iCarsoft.
I notice the lateral/longitudinal data showing more sensible readings moving around a datum of zero but every so often the lateral acceleration would jump to 260ish and the longitudinal acceleration would jump to 65ish - sometimes together. This did not trigger the faults.
When we parked up at the supermarket I noticed the rear left corner height was sat at approx -9mm whilst the other 3 wheels were all close to each other in height. With normal ride height selected I got:
FL = 9mm
FR = 12mm
RL = -9mm
RR = 9mm
When I put the suspension into off-road mode I got:
FL = 47mm
FR = 45mm
RL = 38mm
RR = 48mm
When I dropped it to access height I got:
FL = -48mm
FR = -43mm
RL = -56mm
RR = -42mm
When reselecting normal height mode they returned to:
FL = -2mm
FR = 1mm
RL = -8mm
RR = 7mm
What I have noticed though is a Compressor Temperature which rises up to approx 132 degrees before steadily cooling to 106 degrees before cycling up to 130 degrees again and so on. The Motor Temperature accordingly increases to circa 84 degrees and eventually, whilst driving home I get the "bong" and the warnings as described in my first post.
After a 3 key off/on cycle the warnings cleared and did not recur. When I checked the suspension settings at home they were all almost equal and the temperatures of both the compressor and motor had dropped way down to a more sensible level.
Does the above point towards anything I can fix easily? Could it be as simple as a suspension calibration or does it point towards an intermittent issue with the rear left height?
26th Jan 2021 8:05 pm
TyphoonDisco
Member Since: 18 Jan 2021
Location: Morpeth
Posts: 102
Is it normal to see gallery pressure as high as 1724kPa? That was the reading once I raised the car to off-road mode.
26th Jan 2021 8:42 pm
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 360
Suspension heights - with suspension at normal ride height measure center of wheel to top of wheel arch at each wheel. There are set figures (search). If out of tolerance reset
Bet the compressor was replaced due to leaks causing over heating it until it died. Your compressor is getting hot I think . This tells me the leaks are still there. If not fixed u will likely need another compressor soon.
Remove the air tank and check for leaks on the top of it. Common issue.
Then run car, stop / park and measure wheel to arch heights. Pull the fuse that stops the car self level img (fuse 26?? Search). Leave overnight and recheck heights. Should not drop. If it does the corner that stops has a leak. Fix it.
Work out why the steering wheel is off center, sort, re set steering wheel angle sensor
See what happens.Series one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
26th Jan 2021 8:56 pm
lynalldiscovery
Member Since: 22 Dec 2009
Location: Maidstone
Posts: 7274
Do not forget whilst po might say there were no known issues, he might be telling a white lie, after all he gEt rid of it in the first place!
Did the garage fit the hitachi as that was what was already fitted? or did they fit it as it was the cheapest, could the car have the AMK software installed?
26th Jan 2021 9:15 pm
TyphoonDisco
Member Since: 18 Jan 2021
Location: Morpeth
Posts: 102
Thanks very much, that makes sense. It's likely they've sorted the broken compressor and failed to fix the source of the issue.
I like the idea of removing the fuse and checking the sag in the morning. I have my suspicions about the rear left as it is vastly different to the others.
Is it also worth me checking the individual air struts for leaks or is it likely the air tank?
Thanks again.
26th Jan 2021 9:17 pm
Breg90
Member Since: 04 Feb 2017
Location: Falkirk
Posts: 360
Step through a logical fault finding process.
1st mission is to find a big leak to save compressor. The tank is a likely culprit and comes of easy.
Then find which corner drops in fuse test, search for leak, etc.
It will work fine if you work through it logicallySeries one 1949 - in bits, chassis is strapped to the ceiling in my garage (beside the canoe)
LR 90 - In bits
Disco 3 - currently in bits
26th Jan 2021 9:32 pm
TyphoonDisco
Member Since: 18 Jan 2021
Location: Morpeth
Posts: 102
That had crossed my mind Lynall but I tracked down the previous owner to try and find out some more about the vehicle. I told him the issue I was having and he said he'd not had any problems. He didn't have anything to lose because I bought the car from a garage.
I'm unsure if the garage changed out an AMK. Is a suspension software reset something that can be done with the correct tool? I'm about to invest in a GAP iid BT.
Thanks for the reply.
26th Jan 2021 9:33 pm
TyphoonDisco
Member Since: 18 Jan 2021
Location: Morpeth
Posts: 102
Thanks again Breg. It might sound strange but I actually enjoy fault finding with Landies. It all pays off when you get that feeling of having found a fault and fixed it without paying LR the big bucks!
26th Jan 2021 9:50 pm
TyphoonDisco
Member Since: 18 Jan 2021
Location: Morpeth
Posts: 102
Update:
I raised the suspension to off-road height last night and then isolated the entire system by removing F3 and F26.
Measured all actual ride heights from hub centre to arch.
FL =
FR =
RL =
RR =
Went back to the car this morning (10 hours later) and the ride height had not budged on any corner.
Took the car out again whilst monitoring live data and managed to get the multiple faults to reoccur. Interestingly, the compressor temp at time of failure was quite low.
However, the gallery pressure with the car at normal ride height was in excess of 1300-1400kPa. It definitely seems to be an intermittent issue within the suspension which is causing a single component to reach trip-off point which then excites all of the other systems into failing.
I recycled the key 3 times to clear the warnings, took the car home to park on level ground and all systems appeared more normal. With the ride height at normal I then removed F3 and F26 to isolate the suspension system again. I drove the car up and down the local lanes and apart from the expected suspension warning (30mph max etc) I did not get any multiple warnings.
Furthermore, I don't suspect a leak in the air tank because it looks relatively new, holds gallery pressure well and there are no visible/audible leaks.
My next steps, once the GAP iid BT arrives will be:
1. Ensure the car ECU is running on the correct SW to support a Hitachi compressor in case the recent replacement was from AMK to Hitachi with no change in SW.
2. Carry out a full suspension calibration.
I'll keep you all advised...
27th Jan 2021 2:49 pm
TyphoonDisco
Member Since: 18 Jan 2021
Location: Morpeth
Posts: 102
Oops!
Ride heights at normal were:
FL = 504mm
FR = 512mm
RL = 533mm
RR = 533mm
No sag overnight with system isolated.
27th Jan 2021 2:50 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 14177
Hi
Feel ur pain as I know suspension errors can be taxing trying to pin it down
Also included the pressure table what the compressor should be running at , plus what the ride heights for when u get ur gap iid
Standard setting from the bottom of the wheel arch to the centre of the wheel , found putting some masking tape on the centre of the wheel and marking the centre helped get the right spot every time
front height, 466mm , rear , height 485mm , plus or minus 10mm , so looks like it needs resetting going by ur figures
Think ur getting the 30mph error because the suspension think it’s in off road height or extended
Hope that helps and indeed Plse let us know how things go when u get ur iid , is an awesome bit of kit as ur also be able to reset ur steering wheel angle sensor and of course so much more
Click image to enlarge
27th Jan 2021 4:03 pm
TyphoonDisco
Member Since: 18 Jan 2021
Location: Morpeth
Posts: 102
Thanks Stuart, much appreciated.
I'm an idiot, my heights I listed below were measured in off-road mode so when you factor -50mm to convert to normal ride height and then consider the tolerance of +-10mm they are all there or thereabouts apart from the Front Left.
The 30 mph warning only occurs when I drive with the suspension fuses removed to isolate the fault.
The key is now trying to pin down what is failing within the suspension system which then drags down the other systems. I am erring towards it being an electrical item/sensor or similar because I can't find any mechanical issues/leaks as yet. I will delve into the individual units if the SW and calibration don't work.
27th Jan 2021 5:20 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 14177
Hi
Ur so welcome and no worries as I wondered if u was in off road height
Must admit I was going round in circles until I got the iid, so could then at least sit in the car and read all the codes , including checking all the live data and what the disco is doing
Made life a lot easier , plus there are ways to test ur canbus with a multimeter , even if the steering wheel angle sensor is out can throw errors
Alas had to rebuild nearly all my suspension because it was in such a state , hasn’t been looked after
Glad it helped and ur find the forum and it’s members extremely helpful
can also email the fault code report to ur email or even a printer if the disco is near to one , then clear all ur errors and see what comes back
u codes can normally be ignored , don’t forget if u get stuck there’s plenty of help and indeed Plse let us know how u get on
Also link for the full workshop and electrical diagrams for the D3
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