I have been trying over the last few weeks diagnose the inactive suspension and HDC fault.
I was getting a can bus error and ABS a fault reading on my iidtool, so far I have replaced the wheel sensors,
I did some research and found the connections on the air suspension ECU can cause problems so I removed it, cleaned the plugs and reinstalled. I cleared all fault codes. Then when I get in the range rover and drive and get a small bump in the road, or do a small turn the warning lights go on again.

I did some playing with the iidtoolBt and did a calibration of the steering sensor and all the fault codes disappeared, I went for a 100 kms drive and all was good, then I pulled into a driveway and got the dreaded bong and the dash lights came on.
I again reset all codes and did the steering angle sensor calibration, and drove the 100kms home without and issue. get home pulled into the driveway and bong the faults came on again.

In live values the Steering wheel sensor seems to show positive and negative values depending on which direction the steering wheel is turned, and on centering it shows zero. So I assume it is working , but the first code that comes up on faults sometimes is " Steering sensor Internal fault" so I am leaning towards the ECU being the culprit, even though live values shows it is functioning. I read somewhere you can replace the angle sensor without removing the whole steering column and dash, fiddly but doable in less than an hour?

There are also 2 earth points to check according to a Land Rover Bulletin for the air suspension on either side of the front seats, in Rave CO553 is one of them ,it shows the location in the connector locations, but I think you have to remove the seats to access them under the carpet? bit of a pain in the rectum

I replaced the steering angle sensor and now all previous constant reoccurring faults relating to ABS, HDC and air suspension inactive have now disappeared. So the steering angle sensor must play an important role in the system.

all the electronics seem to be connected one way or other... ... - .- -.




Y. O. L. O.
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Yep, make it hard for fault finding though. I was lucky, I tried the Renew steering angle sensor function and re calibration on IIDtool BT, it then removed the dash warning messages for the inactive air and HDC, then when the boing went off again and the messages came up again, I repeated Steering angle sensor renew ecu functions again, and all was well for a short while and then it would trigger the faults again when driving or turning into a driveway, so glad I got it sorted as it was driving me insane. The air suspension is now behaving itself , vehicle stays level, and no dipping when stopping at traffic lights.