04 X5 4.8 SELF LEVELING SUSPENSION PROBLEMS

[Cdannettell]

The module is located behind the glove box. I had to replace mine. To actually TAKE the old module out, and put the new one in requires actually removing the glove box and getting behind the ducting - but you can "cheat" by just taking off the plate behind the glove box (one Phillips screw, two clips) and unplugging the old module and plugging in the new. I just have the new one set in there for now until my husband can actually disassemble the glove box and mount it.

[vtbmw]

Watch bimmermerchant on YouTube, he points out the location of the module in one of his videos for changing the rear airbags. You can also buy used parts from bimmermerchant. At one point, the one they had in stock was $150.

[r2d20]

I have a working and tested Air Suspension Control Unit for 2002-2005 BMW X5 (E53). The part number is 37146758452. It is behind the glove box. Just listed the item on eBay. 2002-2005 BMW X5 E53 Air Suspension Control Unit 37146758452

[Seany]

This Thread really helped me, hopefully this post helps someone else. Excuse the jumping between past and present tense... I've copied and Pasted from the reports I gave to two separate garages.

My 2005 E53 X5 4.8is had a failed Suspension Controller. Difficult to diagnose, symptoms as follows:

The sensor for the front left (N/S/F) self levelling suspension was disconnected both mechanically and electrically. The plug was undone, and was hanging loose. This was when I bought the car in 2016.


If the plug was reconnected, the computer would throw a "Self Level Susp. Inact" Fault Code on the dash. I found this out the hard way!


An Independent unplugged the sensor and reset the fault for me for the MOT. The car drove 6000km (3750mls) with the sensor unplugged and no faults shown. However I knew of the problem and wanted to get it resolved. Unbeknownst to me he had used a spurious system and "deleted" the defective sensor from the system so it couldn't see the sensor to generate a fault. The car always drove funnily, and I knew something was wrong.

I took the car to a Main Dealer. Their technician then reconnected the sensor on the front left (N/S/F) and found that it was indeed defective. This sensor and it's linkages were then replaced. The computer continued to throw the Self Level Susp. Inact" fault code on the dash however.
The technician then had reason to suspect the front right (O/S/F) sensor was defective, and he then replaced that, and calibrated it etc. The computer continued to throw the Self Level Susp. Inact" fault code on the dash however.

During the course of further diagnosis on the Front Right Self Levelling Sensor, the Technician found that the insulation to the three wires had been stripped back for someone to measure continuity/resistance across the sensor. He also found a piece of one of the wires in this condition under the washer fluid bottle.

He disconnected the wires from the sensor and tested the wires at both ends for continuity and resistance and found that they tested ok. To confirm this, he also fabricated a new loom piece which he ran from the controller to the sensor but found that this made no difference, so he has definitely ruled the wires out as being the cause.

The front right self levelling suspension sensor (O/S/F) was then ruled out as a potential cause of the fault code. The computer continued to throw the Self Level Susp. Inact" fault code on the dash however.

The technician then checked the rear right self levelling suspension sensor and found it to be out of alignment, so re-mounted it and made it straight. As far as I know that is the only thing he did to that sensor.

The rear left (N/S/R) self levelling suspension sensor was never touched.

The technician also inspected the Relay for my Air Compressor and found it looked slightly "charred" and had evidence of getting hot. Apparently this is relatively common. He swapped it out with a new one to confirm it was working ok, but the original one was fine so he put it back in.

The technician then recommended that the Suspension Control Module (P/N: 37146773999) be replaced as he thinks that may be the problem.

On a side note, the Suspension Control Module is located behind the glovebox on my vehicle as it has dual axle air suspension (EHC2) as opposed to a vehicle having it on one axle (EHC1), wherein the module would be in the boot.

Turned out the controller was the problem. Even after all the work had been done, it was still throwing a fault on the front right sensor. Everything that could possibly have been wrong with the sensor had been checked, so it could only have been an internal error with the controller causing the fault, as the sensor was now good/new.

Additional points to note that may or may not help other people:


The linkages on the Self Levelling Sensors apparently are known to
occasionally seize up on the ball joints that they pivot on also. The front
two sensors/linkages are new so they can be ruled out, but the linkages
for the two rear sensors may need to be removed/cleaned/lubed.

The compressor on my car always worked as it should, and the suspension never "went down" on any of the struts in the past to indicate an air leak
on one of the air bags.

When manually raising/lowering the car on the button next to the ignition barrel, you could operate the car in any direction multiple times (7 or 8) before the compressor would eventually trip on High Temp cut out. As soon as it cooled down, the suspension worked correctly again. This is normal for the compressors.


The compressor may be the fault, of course, but I have never had any reason to suspect it. Nor have I ever had reason to suspect an air leak from somewhere on the suspension as the air compressor has never started/stopped repeatedly when driving either. Continuous stopping/starting would indicate a leak on an airbag, and would burn out the compressor quite rapidly. i.e. the seals on the pistons in the compressor burn out and fail.


The Air Suspension on my car had never gone down noticeably on any corner even with the alarm present (which has disabled the Compressor). So Therefore I'm very confident none of my airbags are leaking.

Apparently, the Compressor not generating enough pressure (Less than 5 bar) will also cause the "Self Level Susp. Inact " error too. The control module can fail if it is overworked by switching the Air Compressor on and off repeatedly.

[cammo001]

Originally Posted by Seany

This Thread really helped me, hopefully this post helps someone else. Excuse the jumping between past and present tense... I've copied and Pasted from the reports I gave to two separate garages.

My 2005 E53 X5 4.8is had a failed Suspension Controller. Difficult to diagnose, symptoms as follows:

The sensor for the front left (N/S/F) self levelling suspension was disconnected both mechanically and electrically. The plug was undone, and was hanging loose. This was when I bought the car in 2016.


If the plug was reconnected, the computer would throw a "Self Level Susp. Inact" Fault Code on the dash. I found this out the hard way!


An Independent unplugged the sensor and reset the fault for me for the MOT. The car drove 6000km (3750mls) with the sensor unplugged and no faults shown. However I knew of the problem and wanted to get it resolved. Unbeknownst to me he had used a spurious system and "deleted" the defective sensor from the system so it couldn't see the sensor to generate a fault. The car always drove funnily, and I knew something was wrong.

I took the car to a Main Dealer. Their technician then reconnected the sensor on the front left (N/S/F) and found that it was indeed defective. This sensor and it's linkages were then replaced. The computer continued to throw the Self Level Susp. Inact" fault code on the dash however.
The technician then had reason to suspect the front right (O/S/F) sensor was defective, and he then replaced that, and calibrated it etc. The computer continued to throw the Self Level Susp. Inact" fault code on the dash however.

During the course of further diagnosis on the Front Right Self Levelling Sensor, the Technician found that the insulation to the three wires had been stripped back for someone to measure continuity/resistance across the sensor. He also found a piece of one of the wires in this condition under the washer fluid bottle.

He disconnected the wires from the sensor and tested the wires at both ends for continuity and resistance and found that they tested ok. To confirm this, he also fabricated a new loom piece which he ran from the controller to the sensor but found that this made no difference, so he has definitely ruled the wires out as being the cause.

The front right self levelling suspension sensor (O/S/F) was then ruled out as a potential cause of the fault code. The computer continued to throw the Self Level Susp. Inact" fault code on the dash however.

The technician then checked the rear right self levelling suspension sensor and found it to be out of alignment, so re-mounted it and made it straight. As far as I know that is the only thing he did to that sensor.

The rear left (N/S/R) self levelling suspension sensor was never touched.

The technician also inspected the Relay for my Air Compressor and found it looked slightly "charred" and had evidence of getting hot. Apparently this is relatively common. He swapped it out with a new one to confirm it was working ok, but the original one was fine so he put it back in.

The technician then recommended that the Suspension Control Module (P/N: 37146773999) be replaced as he thinks that may be the problem.

On a side note, the Suspension Control Module is located behind the glovebox on my vehicle as it has dual axle air suspension (EHC2) as opposed to a vehicle having it on one axle (EHC1), wherein the module would be in the boot.

Turned out the controller was the problem. Even after all the work had been done, it was still throwing a fault on the front right sensor. Everything that could possibly have been wrong with the sensor had been checked, so it could only have been an internal error with the controller causing the fault, as the sensor was now good/new.

Additional points to note that may or may not help other people:


The linkages on the Self Levelling Sensors apparently are known to
occasionally seize up on the ball joints that they pivot on also. The front
two sensors/linkages are new so they can be ruled out, but the linkages
for the two rear sensors may need to be removed/cleaned/lubed.

The compressor on my car always worked as it should, and the suspension never "went down" on any of the struts in the past to indicate an air leak
on one of the air bags.

When manually raising/lowering the car on the button next to the ignition barrel, you could operate the car in any direction multiple times (7 or 8) before the compressor would eventually trip on High Temp cut out. As soon as it cooled down, the suspension worked correctly again. This is normal for the compressors.


The compressor may be the fault, of course, but I have never had any reason to suspect it. Nor have I ever had reason to suspect an air leak from somewhere on the suspension as the air compressor has never started/stopped repeatedly when driving either. Continuous stopping/starting would indicate a leak on an airbag, and would burn out the compressor quite rapidly. i.e. the seals on the pistons in the compressor burn out and fail.


The Air Suspension on my car had never gone down noticeably on any corner even with the alarm present (which has disabled the Compressor). So Therefore I'm very confident none of my airbags are leaking.

Apparently, the Compressor not generating enough pressure (Less than 5 bar) will also cause the "Self Level Susp. Inact " error too. The control module can fail if it is overworked by switching the Air Compressor on and off repeatedly.

hi mate , what scan tool does your garage have ? i have a snap on modis and dried the calibration and ended up with the same problem as you with the voltage not changing the mm. after getting a inpa k+dcan cable i reset it and all the sensors are now reading the correct mm. aulthough the car is now on the ground all round and all 3 LED 's are flashing and the pump is just cycling on and off. going to look into it more tomorrow

[cammo001]

OK so I have all the levels set and every corner gets there except the front right.... When the compressor is running the front right is inflating... All the time. But it does not loose air?? It's like there's a leak in the valve block that is allowing the compressor pressure to leak through to the front right bag..

This is giving me a code for pressure remaining consistent (because the pressure is going into the front right when all the valves are closed.... (viewed in inpa)

When the code is cleared and the pump starts again... The front right strut is inflating....