selflevel inactive max height

[ekvals]

Hi.

I know there are a lot of threads regarding the selflevel inactive warning, but i could not find one with the sytomps as i have.

I`ve had the warning for a few weeks now.

I can hear the pump kick in at times, and as far as i can tell, it is not making any unusual noise.

However, when it does kick in, it seems like its struggeling, as the interior lights blinks, and i can here there is a short "pause" of the fuelpump. (My fuelpump makes a quite high "wining" sound when running. Always have)

The height of the car is ok, or not low at least.
In fact, it actually appears to be higher then normal.

I have a little theory about height sensor being faulty, not recognizing that the car is at max height, and the selflevelling trying to jack it further up, thus making the pump struggle.

Any thoughts of what this could be.? If a sensor thing, which one it could be.?

[civdiv99]

Well, I'm assuming here that you have the 4-wheel leveling suspension. If one sensor fails as you suggest, the system will attempt to raise that particular corner. (actually, it WILL raise that corner; ask me how I know).

You can check the height sensors at each corner yourself. It's not difficult, but a bit of a tight space. If any of the tools or processes here don't automatically have you reaching for your meter, consider getting someone to help out.

Pull the wheel where you think the problem is. Using a couple of 10mm wrenches, remove the nylon/plastic link running between the sensor arm and the suspension component. You gotta hold the flats on the little shaft side and remove the nylock nut. Personally I think it's easiest to then spin off the nut holding the bracket also (10mm wrench), and that'll let you maneuver the sensor in your hand. What you want to do is take a good multimeter, and check source (5v), the return, and the signal (min .5v, max maybe in the 4v+ range, no more than that). The left side sensors have 3 wires each, which are the above 3 connections. The right sides have 6 wires each - the same 3 connections for the suspension, and the other 3 do the same thing but for the HID leveling module. These connectors are sealed up pretty good, so backprobing doesn't mean hogging in there - beg, borrow, or steal some genuine needle-like backprobes for your meter. By the way, if you don't have a good meter, you don't necessarily have to blow the good $$ on a Fluke; typical Radio Shack stuff for $50 will do what a regular user wants to do.

Now, I have the wiring layout for the 4 sensors jotted down, but not with me. I'll be grabbing some chow in about 6 hours, so I'll post the specific colors at each corner and what they do when I get back if not otherwise already posted here for convenience. However, with only 3 wires, a couple of checks, and you'll have them identified anyway.

In the meantime, it works like this: There is a 5v supply to one pin, a return to another pin (you can think of as ground, but is not directly tied to ground, but close enough for discussion here). The third line (usually the "middle" wire) is the signal. The sensor uses a Hall effect sensor which just means it uses a variable magnetic field to reflect a relative position internally. However, it also must employ additional circuitry to condition the signal for the computer. (all sensors of this type do) The native raw signal is uV if that, so there's also a little integrated circuit chip in there. This isn't just a simple wiper arm. Anyway, if you have a bad sensor, you will generally read right at 5v across the supply and return lines, and maybe .2 (2 tenths) of a volt from the middle sensor wire to the return. And with the sensor in your hand you'll notice you can re-position the arm, but the voltage won't change. That's all there is to it. Sensor is about $70 and as you see, replacement is maybe 20~25 minutes assuming hand tools to remove and replace the wheel, etc. While the connecting link is off, make sure the joints move freely. I hit mine with some liquid wrench and some water displacement spray if I have the wheel off anyway. After winter that ball/socket joint can corrode, etc. The links are cheap, but still.........

There's generally some discussion about the computer itself failing if it gets wet or otherwise getting whacked. That may be, but the sensor check is still valid. If the power and return are ok at the sensor, it'll give you the variable output based on position, regardless of whether or not the computer knows what to do with it. There's some work arounds if you have a valid sensor output but the computer isn't doing anything with it (assuming this is the case with just one corner), but that's a whole 'nother road to travel. Not getting into that here. Go ahead and do some logical checks and post whaddup and we'll go from there?

There's a way to manually check the accumulator pressure (ok, let's be real. It's really just an air tank) but I'm not going to be able to get into that with you until perhaps the weekend. I'm a little concerned about the voltage fluctuations (?) when your compressor is running. Well, that and the fact you can hear it (I can, but not if motoring down the road with the load floor in place). Consider removing the load floor for a few days and listening to things. That can add to the discussion of what's happening, when.

You might consider getting some diagnostic software for this. A few searches will lead you to a number of options.

With a laptop and appropriate interface, you can manually command the car to raise and lower, and monitor the signals, then verifying with a meter is the final step. Well, that's what I do. That's all a separate topic, but if you are like me, and have to look up "dealer" in a dictionary just find out what such a thing is, and then employ mapping software just to see if one of those strange beings is even in your area (none for me, thanks), then yeah, you'll be wanting to think about getting some diagnostic stuff. Not everyone's thing, though.

[civdiv99]

Here, assuming you have 4-whl leveling.


Position Pin# Colors Function

Left Front
1 Grey/Brown Grnd
4 Grey/White Signal
5 Grey/Black 5v Source

Left Rear
1 White/Brown Grnd
4 White/Grey Signal
5 White/Black 5v Source

Right Front - to height control module
2 Black/Brown Grnd
6 Black/Grey Signal
3 Black/White 5v Source

Right Rear - to height control module
2 Yellow/Brown Grnd
6 Yellow/Grey Signal
3 Yellow/White 5v Source

And since you will see 6 wires each on the right side:

Right Front - to headlight aiming module
1 Black/White Grnd
4 Black/Green Signal
5 Black/Grey 5v Source

Right Rear - to headlight aiming module
1 Grey/White Grnd
4 Grey/Brown Signal
5 Grey/Green 5v Source

[Paulpen]

Some super info here

If you had confirmed there were no air leaks with sufficent pressure and all the sensors were reading as they should with the correct voltages at the module how would you go about testing the module itself ?