Member Since: 29 Jun 2013
Location: London
Posts: 17
Ride height issue - I’m going through the motions.x
I am typing this up more as a thought process than garnering a response, I will be updating as I go along but in case anyone is having similar problems I thought this might help.
2005 Discovery 3 has developed a fault, possibly one of several as I start to dig, hitting 50mph the suspension dropped to access height, the brake/ABS warning light came on and HDC/DSC is lost with fault message displayed on the dash, can’t remember warning message, reading the error message was not foremost on mind whilst travelling on the A406.
After turning off the engine and restarting the system check came back clean, the only issue was when I attempted to raise the suspension to road height it extended to off-road hight and when selected to off-road height it raised to a point I though the body was trying to remove itself from the chassis (it over extended its preset). After turning off and re-starting I lowered the car to access height and raising to road height and it was fine.
I ordered the iCarsoft LR V3.0, however whilst waiting for it to arrive I thought I could start doing some basic checks.
First up check for leaks in the struts, picking a few days when we could do without the car. The car is parked on the drive nose first, the drive slopes down towards the house. I stared the car, lowered the suspension to access height and raised it to road height, allowing the compressor to finish filling the reservoir, before removing the 20amp fuse that controls the ride level, I left the car for 48 hours. Measuring the distance from the centre of the wheel to the bottom of the wheel arch and then measuring again after 24 hrs and 48 hrs. Front passenger = 46cm, Rear passenger = 52cm, Fron drivers = 46cm, Rear drivers = 51 cm.
I should add the car lowers and rises as it should, it is not sluggish when raising/lowering, no unusual noises or excessive noise and no obvious sounds of an air leak and no error messages on the dash.
After 48 hours their was no difference in height so can be fairly confident that the struts do not have air leaks so re-instated the fuse.
After receiving the diagnostic tool I checked the RLM (ride level control module) only, I have not as yet completed a full diagnostic of the car as I don’t want to be run down a rabbit hole.
There were 8 faults detected, as follows:
C1A36-01 State: Intermittent Exhaust valve
C1A03-92 State: Intermittent Front left height sensor
C1A04-92 State: Pending Front right height sensor
C1A06-1C State: Intermittent Rear right height sensor
U0416-86 State: Historic Invalid data received from vehicle dynamics control module
C1A07-62 State: Intermittent Cross articulation
C112F-72 State: Historic Air spring valve
C1130-66 State: Historic Air spring air supply.
I have no way of knowing what of these are relevant to the current issue. As the second owner (8 years) I do not know what previous works had been done. It was a works vehicle and had off road use. As the second owner I have had front rear lower and upper control arms replaced, transmission fluid and filter change, EGR valve work, new glow plugs, track rod end replacements and new wheel bearings on two corners.
I erased the fault codes, started the car, lowered, raised (road /off-road) then lowered again to road height. Checked for faults, no faults recorded. The car has had some local use, below 50mph, following which I checked for faults today, 2 faults;
U0122-87 State: Intermittent Lost communication with vehicle dynamics control module and,
U0416-86 State: Pending Invalid data received from vehicle dynamics control module.
I understand both of these faults can be linked to numerous issues and not solely an issue with the ride height module and it’s associated ancillaries but the transmission, steering angle sensor, ABS sensor/wiring and a host of other nasties.
My next move was to take the car for a run over 50mph, since that was when the initial problem occurred, however before that could happen we had a large deluge of rain that I have since discovered water has entered inside the front drivers side footwell (renewed the passenger sunroof drain pipe 4 years ago). New drain hose and end piece ordered so before I do anything else I want to get that repaired and the carpet dried out as the ride level control module is that side of the car I don’t know if moisture needs to be a consideration in my fault finding process
This is where I am currently and will update again once the water ingress is sorted and I have taken the car for a longer run.
UPDATE: I did not mention above that when the suspension dropped previously the ‘bonnet open’ and ‘tailgate open’ notifications were displayed on the dash.
This morning I checked the upper tailgate micro switch for and connection for condition. The micro switch is in excellent condition as was the connection. Looked clean and dry, no visible signs of water ingress. I separated the connection and tapped it, their was some dust or powdery stuff that came out so I sprayed the connection with contact cleaner before reconnecting.
Testing the voltage coming through registered 11.98 volts which got me wondering about the battery or alternator being a likely culprit for the errors.
With the bonnet I cleaned up the switch as it was full of grease and dirt that had sealed up the drain holes at the base, both the switch and the wiring connection is excellent, no signs of rust or corrosion and the wiring to looks good.
Next I moved on to the battery. The battery was replaced in 2015 (so just over 7 years old). It was charged Thursday (registered 12.7 volts both with a tester on the battery and ECU diagnostic tester), the car was driven Friday locally for shopping and has not been moved for 27 hours but I have been locking and unlocking quite a bit, opening and closing the tailgate (I have interior lights turned off) and running the diagnostic in that time.
I have a Ring smart charger that I use a couple of times a year just to reconditioned the battery and top up. This morning using a volt meter direct to the battery it registered 12.24 volts. Having the ignition on using the ecu diagnostics it registered 11.95 volts (12.03 max).
Leaving the ignition for several minutes whilst playing about I received two fault messages on the dash in addition to the bonnet and door open message, “special programs not available” and “HDC system fault”
Using the Ring charger I checked the power going into the battery from the alternator, completing the alternator test three times all came back with a “F07” error pointing me to a “poor functioning regulator”.
Checking the power going into the battery both under load (lights, air con, stereo on) at 2000 rpm and under no load at 3000rpm I was getting 14.92/14.90 volts, very little difference between the two.
With the engine off following 30 minutes of the engine running the battery was registering 12.84 volts but interestingly I was no longer getting the special programs or HDC fault messages so I am guessing the battery is playing its part in this. I will post this part about the battery as a separate post to get some feedback and I will update this post in due course.
UPDATE
Had the car on charge for four hours, registered at 100%, so have run a number of tests to gauge the voltage at different states:
Volt @ Ignition Off 12.75
Volt @ ignition on, dropped to 11.88v recovering to 12.24
Volt @ crank/start engine dropped to 11.03
Volt @ idle (no load) 14.36
Volt @ idle (with load (headlights, air con)) 14.35
Volt @ 3000RPM (no load) 5 seconds 14.43
Volt @ 2000RPM (with load with load (headlights, air con)) 5 seconds 14.46v
Volt @ idle after 15 minutes 14.40
I will repeat this again after a few days of no use and see how the results change but I am ordering a new battery.
UPDATE: the new drain tube arrived today (24/8), whilst under the steering column I had a good look and feel around the steering angle sensor.
I noticed the yellow/white plastic sleeve was not completely cantered with the cv joint but as I have no frame of reference I don’t know if it has always been like this, their is no play in the part, could not move it by hand and wiggling the steering wheel side to side it moved with the column, no slack and everything looked good visually. I had read this can be an issue which makes sense if at speed the angle sensor is giving a false reading. It took a couple of minutes to recalibrate the SAS.
Whilst picking up the new car battery it gave me the opportunity to give the car a run on the North Circular at over 50mph 🤫… 50mph at speed camera points, obviously 😬 … but the good news is no faults on the dash and no lowering of the suspension, the only issue was a “bonnet open” was displayed, the tailgate switch clean seems to stopped the ‘tailgate open’ message on the dash. Jumped out at the lights and slammed the bonnet down, round the roundabout and gave it another boot along a section of the North Circular, no issues… then gave is a good run over speed humps, around a couple more roundabouts and no issues.
Took the new battery out of the boot, closed the door and the suspension vented the rear to level the car, so all good 👍
I run the diagnostics on the ride level control module and only 1 fault was displayed ‘U0146-86 State: Historic Invalid data received from vehicle dynamics control module’. I hadn’t cleared the two codes from last use and as this states ‘historic’ I am not going to look any further in to this information code.
Have I fixed the problem?
Did I need to buy a new battery?… probably, it is 7 years old.
Only time will tell if it is fixed, I’ll buy a new bonnet switch as my cleaning the existing switch hasn’t stopped the intermittent bonnet open message.
I’m going to fit the new battery tomorrow, have new parking sensors to fit at the weekend, plus it will get a few more runs at the weekend so keeping my fingers crossed 🤞 .
If it works out I might even treat the car to a full service.
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