SLSI on and the switch LED goes off _ problem sovled!!!
 

Hi all! The story is as below:

My X showed SLSI today and the switch LED stayed at mid level, I tried to raise or lower the X, the LED just flashed several times and stayed at mid level. Then I used GT1 to run DIS to check the fault code, it showed something like ".... constant...." (I don't remember it). Then I run all the test plan in EHC2, like air pump test, level sensor test, etc., and all the component seemed worked ok. I can 100% ensure you that all air bags are not leaking. After the DIS test, the switch LED went off. I cleared all the fault code and exited DIS test, take out the car key for 5 minutes and start the engine again, the SLSI backed again. The switch LED stayed off. I run the DIS to check the code, no code this time.

Can anyone help me to solve the problem please?!

Anybody has any idea here?

Mine didn't throw any codes/errors unless it actually had the message up to say it was inactive. It was then that I could see the sensor values were weird.

On another post, someone said you could only test with the driver door closed, otherwise it wouldn't work either.

Thanks for your comment.

Today I used DIS to run the diagnosis and test again, no error codes, every test including 'check, ride-level sensors', 'check, solenoid value', 'check, air supply system', 'check, compressor relay', 'check, value, pressure accumulator', 'check, supply, pressure accumulator', 'vent pressure accumulator'. All the tests run well without fault, I also run SSS to encode the EHC2 module again, it completed with no problem. But the 'Selfleveling suspension inact' warning letter still show in the cluster, only problem is the LED on the air suspension adjust switch does not go on. After the diagnosis and tests, I am pretty sure that the problem is the switch itself. Just one question, does the 'selfleveling suspension inact' warning be triggered by just the faulty switch without other fault? Thanks for help.

By the way, the 'selfleveling suspension inact.' warning won't be triggered by opening car doors, it just can not raise or lower the car when door(s) is/are opened.

EHC 74 Accumulator filling requested pressure remains constant? - If thats the code its normally due to the air compressor needing a rebuild.

If the error is on the dash you should have some faults stored in the EHCII module, scan it again.

Look at My post on similar issue. compare the voltages and heights, then change height and lok at voltages again, as suggested by fmugur, then look at all your wiring connectors for corroded wires. This is my next step. My LED is off and my cluster states Self level inactive, but no codes are logged. I do believe it is the module, but I need to rule everything else out before I plunge into a module. Switch is a slight possibility as it only porovides a ground to the SLS module.

Thanks for comment!

I scanned the air susp. system with DIS 2 times more yesterday, still no error code stored in the memory. The SLSI still exists in the cluster, switch LED still off. I tested all the things in DIS test plan, all the level sensors looked worked fine, the voltage seemed normal and they reacted well during the loading test. I also used SSS to recode the module, it also reacted well and the recoding process completed without problem. I will check the connection of all level sensors, but I still think the problem maybe the switch itself since the switch LED never goes back again after it went out.

You can access the switch led through INPA and operate them through there, try that before replacing switch

I don't have INPA, I only have the GT1 yellow head. Can I use GT1 yellow head with DIS or SSS to test the switch?

Hi all! I just have the problem solved today.

I used DIS to run the diagnosis again to check the fault code, no code found but the SLSI still was on and the switch LED still was off. I just run all the test again and everything worked fine. Finally I run a ride level adjustment under function test (see the pic I uploaded upstairs), the system asked me to input every corner's height in mm and I inputted all the figures after measuring the height with a ruler. Then the amazing thing happed, the car raised to normal height and the switch LED went back, the SLSI warning went away. Now everything backs to normal. I tested driving my x for a while, nothing wrong. Problem solved! That's it!

Motorsport1207, I think you problem is same with mine, so just use DIS to run the ride height calibration and you will be fine.

I now attach the pics that I took during testing in the DIS control unit functions.