Member Since: 29 Mar 2021
Location: Durham
Posts: 6
Ride Height Sensor Pin Setup
Good Afternoon Everyone.
Currently playing with ride height sensors on my discovery 3.
After looking at the technical information.
Pin 1 - 5V
Pin 4 - Signal
Pin 5 - Ground
Tried testing the sensor off the car using resistance and voltage measurements but nothing working at the minute.
Does anyone know what signal actually is ? Voltage / Resistance ??
Bought 2 sensors and still no further forward.
Thanks for any help anyone.
29th Mar 2021 3:50 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5091
The signal is a variable depending on the position of the sensor, typical operating range is from 1.5v to 2.9v. Supply is a constant 4.91.
What problems are you having?yµ (idµ - eAµ) ψ=mψ
29th Mar 2021 5:24 pm
syrusuk
Member Since: 29 Mar 2021
Location: Durham
Posts: 6
Hi thanks for the reply.
I got a permanent fault on rear passenger side height sensor.
I probed the wires and the signal was a constant 4.8v not changing when height sensor was moved.
I purchased new height sensor thinking that was the fault and same problem.
Really unsure what to do now
Many thanks James
29th Mar 2021 8:55 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5091
Are you looking at the correct wire? You would expect to see 4.8v on the feed but not on the signal side!
It's a graduated voltage depending on the sensor position. 1.5v (susp at lowest setting) and around 2.9v (fully raised).
If you're sure you are looking at the correct wire then you might have a short. Have a look at the large block terminals on the n/s/r chassis rail behind the wheel. The cables entering/exiting the blocks can become frayed over time!
Apart from the sensor end of the wiring loom, the other area worth a look is the block terminal connectors behind the n/s/f headlamp. If you have diagnostics you can see the sensor real time operation in "live values"yµ (idµ - eAµ) ψ=mψ
29th Mar 2021 9:31 pm
L319
Member Since: 14 Dec 2013
Location: Herefordshire
Posts: 2083
Sounds to me that there is a break in the circuit from the sensor , so there is no load to vary the voltage
30th Mar 2021 7:52 am
syrusuk
Member Since: 29 Mar 2021
Location: Durham
Posts: 6
Good Morning,
Yes checked the Pin configuration once again.
The signal wire shows 4.35V what ever position the sensor is in.
I purchased a new sensor thinking it was the fault and this sensor shows 4.5V on the signal wire.
I will try and check the wiring to the sensor including the plugs on the chassis and see if i get lucky.
Thanks so much everyone for the advice, really appreciate it, James.
30th Mar 2021 8:14 am
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 14187
Hi
Does this help u, enclosed wiring so u can see what colours goes to what pin , along with the voltages
Also a parts diagram seeing there handed, can then 100% ensure there correct , pic also shows the location of ur suspensions ECU as indeed another point that u might wish to check for the signal and power voltages to ensure there the same as what u have at the height sensors
Plus of course checking the earths are ok with a multimeter
Personally would get some electrical cleaner , if u can put the disco into off road height to allow u better access , disconnect ur battery and some axle stands to be on the safe side , pull the height sensor connectors off, check wires and pins , then spray them, also check back from the connector wires to ensure they haven’t chaffed anywhere
Reconnect battery then check with a multimeter the connector for ur supply and signal voltages on height sensors
plus 1 in checking the NSR and behind ur headlight connectors , if u still have an issue then think ur have to check for loom continuity along with the above regarding the suspensions ECU
Hope that helps a little
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30th Mar 2021 9:06 am
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 14187
Also just in case included the suspensions ECU pin layout , so u can at least check for continuity from the connector to height sensor and then outputs and signals back with a multimeter
Hope it helps
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30th Mar 2021 9:27 am
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 14187
Picture of the NSR connector , the left hand rear height sensor goes into connector CO391 , pins 12/13/14
Can use ur multimeter to back probe both sides of the above NSR connector to ensure the pins are ok on each side , including doing a test from the height sensor to the connector seeing there close to one another
Connector CO867 on the suspensions ECU
Hope it helps
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30th Mar 2021 9:36 am
syrusuk
Member Since: 29 Mar 2021
Location: Durham
Posts: 6
Hello Sir you are a international.
Okay,
So ride height sensor has 5v supply and Ground.
The Signal Wire when disconnected from wiring side of car shows 4.33v
The wire going from sensor to ECU shows 0.00v
So ordered a OE Sensor from Dealership coming tomorrow.
Fingers Crossed.
Thanks for your help, I will keep you posted !
30th Mar 2021 1:28 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 14187
Hi
Ur so very welcome , always a team effort and indeed Plse let us know how things go
30th Mar 2021 9:42 pm
Globetrotter448
Member Since: 21 Mar 2017
Location: Londonderry NSW
Posts: 1822
Well Mr GS you excelled once more . You must have a wealth of information or just time on your hands
30th Mar 2021 11:50 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 14187
Hi
Shucks ur make me blush, lol
Indeed have to much time on my hands , I need to get out more
Hope this finds u well buddy
31st Mar 2021 3:27 am
syrusuk
Member Since: 29 Mar 2021
Location: Durham
Posts: 6
Good Morning Everyone,
Well I cant thank you enough.
Went to Stratstone and bought a new ride height sensor £84.82 + VAT and my problem is fixed
Copy sensors are no good for nothing.
So thank you everyone for your help. Just need to fix the problem of the compressor running constant now and I'm laughing!
Have a great day,
James
1st Apr 2021 8:30 am
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 5091
That's great, but we could have told you if you'd thought to mention you had a non genuine sensor fitted.
If the compressor is constantly running you most likely have a leak somewhere. It will eventually stop once the temp threshold has been breached.
Again, look in "live values" they really are your friend in diagnosis! yµ (idµ - eAµ) ψ=mψ
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. You must have a wealth of information or just time on your hands 
