BMW X5 F15- Chassis Restriction - EHC Suspension adjustment keeps failing

[pulgalouka]

Hi all,



Need help. My friend has a 2015 BMW X5 F15 5.0 Petrol, 52K KM with the Chassis Restriction Malfunction error on the dashboard.

The car has rear air suspension and according to him, the car was sagging on one side, rear right about a year ago, he got the air bag replaced and all was fine.

A few weeks ago, he got the Chassis Restriction Malfunction error and the car rear raised high and stuck there. He took the car to the BMW Agents who replaced both rear height sensors but the problem was not resolved. They wanted to change the air compressor next at close to $2K, he obviously got the car out to an Indy shop who according to him, serviced the compressor and replaced the compressor discharge valve. The suspension got back to normal height and all working as it should. The car do not sag and the compressor works perfectly, but the Chassis Restriction Malfunction error on the dashboard is still there. So he brought me the car to have a look and these are the present errors I got with ISTA+:

480116 – ICM: Carrying out ride height adjustment.
480117 – ICM: Carrying out ride height adjustment.
D354D0 – Signal (filtered vehicle ride height, 52.0.2) invalid, transmitter ICM.
D71402 – ICM interface (rear left sensor 0xE4): signal invalid.
D71403 – Ignition control interface (rear right sensor 0xE4): signal invalid.
E69A41 – ICM interface (ride-height, vehicle, filtered, ID: 0x0E4): signal invalid.
E6AC64 – ICM interface (ride-height, vehicle, ID: 0x0E4): Signal invalid

So based on the errors above, it looked to me that the suspension needed a height adjustment but I have tried a lot of times and keep on failing, “the calibration was unsuccessfully” or something like that at the end of the procedure.

I measure the wheels and enter these values:
“The following nominal ride-level height was ascertained: rear axle: 724mm. front axle: 734mm

The following ride height values were determined by the sensors:
Rear left: 524, Rear right: 721

When I try to read the sensors, the rear left keeps reading 0 (zero) while the rear right shows -2.0 degrees if I am not mistaken.
That is with both new sensors installed by BMW agents and with the old ones.

So something tells me that the rear left sensor is not functioning correctly, or its signal seems to be interrupted, because it doesn't matter which sensor we install and test, the error its the same. so something on its wiring maybe?!. So I checked for power at both rear sensors, both reading just over 5V with ignition on. Traced the third signal wire from the sensor, but it goes deep toward the front of the car, I thought it would go to the EHC module on the rear left by the fuse box, but its not! Can someone please share a diagram or tell me where the signal wire goes to?
I need to know where the third signal wire from the sensor goes to, so that I can check continuity or if there is anything else I can try…. I am at lost and this is the last thing I think I can try.

Has anyone seen this issue before?

Thank you
Pulgalouka

[Leslie]

There is some info on this thread on the air suspension although it does seem you have a left rear sensor error but as it is actually reading id look at the link arm to it to it see if all looks ok

viewtopic.php?t=19441

[pulgalouka]

Hi Leslie,

thanks for the reply. The sensor are new, installed by the agent. I have gone and checked them even replaced them back with the old ones and same problem.
What I think will help me now, is to know where the sensor signal wire goes to, so that I can trace it and make sure its not cut somewhere.

thanks

[Jonty]

Hi there Pulgalouka,
I myself recently have run into the exact same issue as you on my own x6 f16 with identical fault codes. I was wondering if you came to a solution and what your solution involved.

[Jonty]

Hi there Pulgalouka,
I myself recently have run into the exact same issue as you on my own x6 f16 with identical fault codes. I was wondering if you came to a solution and what your solution involved.

[pulgalouka]

Hi Jonty,
no, I did not. I end up returning the car to the owner and he end up selling it.. sorry man. But, someone later told me I should check the control box under the passenger carpet, and it would probably be wet. never got a chance...