Multifunction display issues after parking light change

[NZLSAF 0]

Hi all, changed the parking lights the other day in my 540i to some nice bright LED ones. Unfortunately due to the drop in resistance in the system the car rejected them and threw up "check park lights" on the display.

The next day i swapped them back but have noticed they have done something to my multifunction display (radio tv etc unit), and to my steering wheel stereo controls. The radio still works as do all the other functions on the screen, i just cant see any of them while the car is running nor can i adjust them while the car is off....?

1. the sreering controls no longer work

2. the display stays blank with the time not changing until i complete my journey and turn the car off... ie the time and date on the bottom is displayed with the rest of the screen as black. I noticed it flickers when i have my lights on and off, i am thinking there is a relay that is blown or maybe a fuse.

Advice and assistance appreciated.

[NZLSAF 0]

Upon further inspection the unit works fine on the first turn key for the ignition, but to ACC or ON the unit blanks all out but the "turn monitor off" and "television" selections on the main menu... could this somehow be a coding issue, i never had any issues in the past?

[gadgetman 0]

Have you tried disconnecting the battery for 20-30 minutes and the reconnecting it?

If the fault returns with the battery reconnected you've got a fuse or module fault, if it isn't, it was just a software hiccup

[jochen 4]

Upon further inspection the unit works fine on the first turn key for the ignition, but to ACC or ON the unit blanks all out but the "turn monitor off" and "television" selections on the main menu... could this somehow be a coding issue, i never had any issues in the past?

Assuming the vehicle is an E39 540i:

Remember:

Steering Wheel controls only work with Ignition in Pos 2 (ON) position. They are not powered up when key is in Pos 1 (ACC)

If the nav system looses the ibus data connection, then the steering wheel controls will not work, the system will not be able to talk to the instrument cluster, and the trip computer menu item will disable after a period of time. All functions that require data from the instrument cluster will not be possible.

But Television and Navigation will still be displayed, as their ibus connections are in the same nav loom.

If your accessory position (Pos 1) on the ignition switch is faulty, then the board monitor will not turn on the display (ie: things will work but you won't see them). Check the text display on the instrument cluster to confirm that you are able to control radio, CD, etc.

[NZLSAF 0]

Assuming the vehicle is an E39 540i:

Remember:

Steering Wheel controls only work with Ignition in Pos 2 (ON) position. They are not powered up when key is in Pos 1 (ACC)

If the nav system looses the ibus data connection, then the steering wheel controls will not work, the system will not be able to talk to the instrument cluster, and the trip computer menu item will disable after a period of time. All functions that require data from the instrument cluster will not be possible.

But Television and Navigation will still be displayed, as their ibus connections are in the same nav loom.

If your accessory position (Pos 1) on the ignition switch is faulty, then the board monitor will not turn on the display (ie: things will work but you won't see them). Check the text display on the instrument cluster to confirm that you are able to control radio, CD, etc.

Jochen, first off thank you for your response.

In position two (first turn), the screen turns on and i have full control, as soon as i go to position three (second turn) then things start blanking out.

The text display on the cluster stays blank so does not display changing radio stations for example even though i can manually change them on the unit itself (as opposed to through the steering wheel as i did before).

So does this leave me needing to fix/replace the ignition switch or the ibus connector... i seem to be suffering from symptoms of both issues?

Cheers

Edited August 28, 2012 by NZLSAF

[NZLSAF 0]

[jochen 4]

In position two (first turn), the screen turns on and i have full control, as soon as i go to position three (second turn) then things start blanking out.

typical sysmptoms of

a) a flat battery, which cannot handle the extra load of the the engine etc when ign switch moved to Pos2. Many systems shut down under low voltage. Solution: charge the battery!

or

B ) a faulty ignition switch, where the contacts inside the switch are worn. Solution: replace the electrical part of the ign switch with a new (not 2nd hand) one. Easy and cheap. If you fit 2nd hand, you don't know how worn the 2nd hand switch is, and the problem may reappear a few days/months/years later.

Missing data on the board monitor display can be caused by a broken ibus connection to the ignition cluster - OR by corrupt data on the ibus due to poor ignition switch contacts (causing noise on the 12V line)

Symptoms point to bad ignition switch, as it is highly unlikely you would have an ibus physical wire problem as well as another problem at the same time.

Tip: wiggle the key when ignition is in Pos2: does it make the symptoms come and go, or change at all? If so, ignition switch is definitely worn and must be replaced.

Edited August 29, 2012 by jochen

[NZLSAF 0]

I put the battery on a tester the day and i got a measurement of 12.9v with 816SAE so i am thinking that its not the battery at fault. Guess its off to bmw for a new ignition switch...?