Rear right ride height sensor/LRA error, Headlight adjustment

[Clavurion]

Rear right level sensor has two separate sensor circuits for suspension and xenon auto levelling 3+3 wires. The other 3 wires are connected to LCM or on early models (->9/2002) to separate LWR module.

It's those grey wires in your first pictures. Grey/white, grey/brown, grey/green.

[Bmwe5320023.0]

I used pin 1 as ground and checked pin 5 for power. It provides 5+ volts.
Why am I getting that bmwscanner error then?
Do you think it's faulty sensor?

[Clavurion]

Originally Posted by Bmwe5320023.0

I used pin 1 as ground and checked pin 5 for power. It provides 5+ volts.
Why am I getting that bmwscanner error then?
Do you think it's faulty sensor?

Not unusual for these sensors to fail. With proper diagnostics you could see what voltage the signal line is showing and if it changes when sensor lever arm position is changed.

[Bmwe5320023.0]

I see. What you're saying that the voltage on pin 5 should change with moving the sensor around? Should I measure with DMM?

I did a few tests here.
With the sensor connected.
If I clear that error in bmwscanner and rescan right away, I get a weird "unknown" error.


Now scanning with the sensor connected in INPA I get these



Now if disconnect the sensor, I get a few different readings


It's funny I'm losing power to the front sensor if I connect the rear sensor. Is the rear sensor shorting out the light module or something?

[Clavurion]

Sounds like the sensor is goosed. If you want you can swap the front and rear sensor for test purposes. (Check that the pin locations for needed wires are the same as original front/left rear sensors only have one working circuit and the other 3 wires are not connected.)

[Bmwe5320023.0]

I got a few used sensors and tried swapping them.
Now I only get 0 volts in INPA. Whether the sensor is connected or disconnected. The connector is still measuring 5V with a multimeter.
I tried swapping different sensors in the rear, but nothing seems to change in INPA or bwm scanner.
INPA doesn't show any errors.
Bmw shows a weird shadow error "terminal 30"
I guess it's not active as it's shadow, but if won't go away.
I know terminal 30 is main battery power, but my car is plugged to a battery maintainer.

If any of you don't mind sharing screenshots from INPA and bmw scanner, I'd appreciate it.
I don't exactly know how to diagnose this issue.

[Bmwe5320023.0]

[wpoll]

Terminal 30 shadow codes relate to the main battery voltage being too low. For instance, if you remove the battery, then replace it, then check for codes, you'll have a terminal 30 shadow code.

As for diagnosing the ride height sensor, I'll try and grab some INPA and/or PASoft screen shots for you but it won't be until the weekend - winter has arrived down here and I won't be able to get into my garage with my car (since my wife's car is in there!) until then...

[Bmwe5320023.0]

Winter?! Like do you mean piles of snow? I thought new Zealand was a warmer place!

If you can grab these I'd appreciate it.


Now my battery was pretty low, barely 11 volts. I didn't realize how fast it draws power with the key on "run" position...
Now I connected it to 2 amp charger, it doesn't seem to get higher than that.
I'm trying to install ISTA in the meantime, apparently it's easier to use and more comprehensive than INPA.
Then I'll continue troubleshooting.

I scanned the error with bmwscanner again after recharging the battery. The error came up as something "rear sensor error". When I cleared and rescanned, the error would only come back as "unknown"
Maybe ISTA will give me a better idea of what's going on if I can get it working

[Bmwe5320023.0]

Found this description for E38, probably very similar operation

Automatic Headlight Vertical Aim Control

The load status of the vehicle is recorded by sensors mounted on the front and rear axles. The sensors are mounted at the front and rear right between the stabilizer bar and axle carrier. The control module for automatic headlight vertical aim control is activated dependent on the motors for headlight height adjustment.

The right and left headlights are adjusted simultaneously.

With a low power requirement, the headlights are kept in the present position.

The power supply for automatic headlight vertical aim control is switched through from the light module. This takes place when switching on the parking light terminal 58 or after engine start with terminal 61 "engine running".

The control module for automatic headlight vertical aim control is informed when the headlight is switched on via the K-bus.

Control is not possible if the system voltage is too low. The motors for headlight height adjustment can no longer be driven and the inclination sensors are no longer supplied with voltage.

Diagnosis of the automatic headlight vertical aim control system can only take place when a light module is installed and terminal 58 or terminal 61 is active.

In case of fault, control is stopped immediately and a corresponding fault code is stored in the fault code memory. The last position of the headlights is frozen.

When the side light is switched on or the engine started, the electronic control carries out a reference run with the stepper motors and then assumes the basic setting

Based on this INPA screen, the modules must be the same on E38 and E53