WyvernNZ 0 Report post Posted May 9, 2008 Hi all, My e46 dashboard has started dimming across the clock, mileage, gear display bar. The clock on the stereo also dims, but the dials stay fully lit. The dimming lasts for a few seconds and then goes back up to full power. This has happened twice in the last 2 weeks. Someone at work mentioned that the lights dim to remind you that your service meter is getting close to zero. Is this true? Anyone know what this all means? Cheers. Quote Share this post Link to post Share on other sites
jochen 4 Report post Posted May 10, 2008 (edited) My e46 dashboard has started dimming across the clock, mileage, gear display bar. The clock on the stereo also dims, but the dials stay fully lit. The dimming lasts for a few seconds and then goes back up to full power. This has happened twice in the last 2 weeks. Someone at work mentioned that the lights dim to remind you that your service meter is getting close to zero. Is this true? Anyone know what this all means? Dashboard illumination brightness is controlled by a pulse-width modulation signal which comes from the LSZ (Light Switching Centre) The illumination is terminal 58G, the red wire with a green stripe. NOTE: Never put 12V on this wire! You'll overpower the illumination LEDs and burn them out. The illumination signal goes to all switches and controls that are illuminated: eg: cigarette lighter, door switches, heater controls, radio, and all switches. The illumination is fed by the LSZ (Light Switching Centre) which is immediately behind the light switch - when the headlight switch is removed, the whole LSZ comes out with it. It is easy to remove: pry off the trim panela round the light switch, undo the screws, and then the switch + LSZ slides out. When you turn the dash illumination adjustment, it alters the pulse-width modulation on the 58G illumination wire. Your problem will be either: 1. Faulty or failling LSZ. If you are comfortable with electronics, you could dismantle it and resolder all components that get hot, or are large (electrolytic capacitors, transistors, etc) 2. A simple dirty potentionmeter in the illumination control. dismantle the LSZ to gain access to the illumination control. Spray contact cleaner or good old CRC (a little, not a lot!) into the dimmer potentiometer and then move the pot through its range to spread the contact cleaner around and clean the contact surfaces. See if it helps. It has worked wonders for me many times with older, dirty pots in many electronic items. Sometimes through the pot can be so sirty or corroded or oxidised that no spary will help forever. Then replacement of the pot is the only cure. 3. Bad connection on the 58G illumination signal (red/green wire) as it is distributed throughout the vehicle. Monitoring which lights are affected and then referring to the wiring diagram will help you find the intermittent connection. If the variation of the illumination only affects SOME but not ALL of the illuminated switches etc at the same time, then you must have a faulty wire connection in the red/green wire. Be aware that some displays (radio, climate control, instrument cluster) have a photo sensor which alters the brightness of the display based on ambient light levels. So these displays may not react as quickly to a change in the PWM illumination signal, and they may mask a rapid fluctuation of the PWM signal, which might make itself visible on eg a switch illumination, but not on the radio display. You can also test the instrument cluster illumination as follows: System test (Test No. 2):This system test facilitates simple visual assessment of the instrument cluster (pointer instruments, displays, lighting, warning lamps and indicator lamps). Selecting system test function The system test is started by pressing the left-hand button in the instrument cluster (trip recorder reset button. The button must be pressed and held with the ignition lock in "0" position, now turn the ignition lock to position "1" (terminal R radio setting) and release the button. When "tESt 1." appears in the display press the button once again, "tESt 2." now appears. After a short period of time, the display changes to "tESt 2.0". The system test can now be started by pressing the button once again. By switching the terminals, ignition lock from position "1" (terminal R radio setting) to position "2", the two-coloured indicator lamps are activated yellow and red. On completion of the system test, it can be repeated by pressing the button once more. These elements are: All pointer instruments (pointers are moved once over their indication range) All LC displays with a segment test and their background lighting Indicator and warning lamps for: High beam Oil pressure (red) (ignition lock in position 2/terminal 15) or Oil level (yellow (ignition lock in position 1/terminal R) ASC Front/rear fog lights Windscreen washer fluid level "CHECK ENGINE" EML (EPC) / MDK Coolant level Brake pad wear Tyre pressure control Cruise control Belt warning Fuel reserve Coolant high temperature Left/right direction indicators Windscreen washer fluid level Shift indicator (if automatic transmission is coded) Cruise control (Tempomat) cut-in Battery charge indicator lamp General brake warning lamp (at terminal 15) All test functions, apart from test numbers one and two, are interlocked and must be released by means of test function number nineteen. Selecting test functions The test functions are started by pressing the left-hand button in the instrument cluster (trip recorder reset button. The button must be pressed and held with the ignition lock in "0" position, now turn the ignition lock to position "1" (terminal R radio setting) and release the button. Once " tESt 1. " appears in the display the required test can be selected by pressing the button. " tESt 2. " " tESt 3. " " tESt 4. " etc. now appear in the display. After a short time, the display changes to " tESt x.0 " (x stands for selected test group), by pressing the button once again, it is possible to switch to another test in the test group or, as in the system test, start the respective test. If the test is a locked test (test 3 to 21) the lock is released with test 19 by pressing the trip recorder button when "_L_oFF" appears in the display. The display then jumps to test 0 so that the corresponding test group can be selected by briefly pressing the button. Edited May 10, 2008 by jochen Quote Share this post Link to post Share on other sites
mammoth 0 Report post Posted November 21, 2008 Still new to this... I am having what I think is a similar problem. My outside temp reading has dimmed and looks to also have dimmed part of the odometer display (this is on an E39, instrument display). Is the fix for this similar to what you have discussed? I'm pretty good with the mechanical side of things, but electrical scare me a little. Are you in Wellington at all? if not, is this something that most competant electricians could handle? Dashboard illumination brightness is controlled by a pulse-width modulation signal which comes from the LSZ (Light Switching Centre) The illumination is terminal 58G, the red wire with a green stripe. NOTE: Never put 12V on this wire! You'll overpower the illumination LEDs and burn them out. The illumination signal goes to all switches and controls that are illuminated: eg: cigarette lighter, door switches, heater controls, radio, and all switches. The illumination is fed by the LSZ (Light Switching Centre) which is immediately behind the light switch - when the headlight switch is removed, the whole LSZ comes out with it. It is easy to remove: pry off the trim panela round the light switch, undo the screws, and then the switch + LSZ slides out. When you turn the dash illumination adjustment, it alters the pulse-width modulation on the 58G illumination wire. Your problem will be either: 1. Faulty or failling LSZ. If you are comfortable with electronics, you could dismantle it and resolder all components that get hot, or are large (electrolytic capacitors, transistors, etc) 2. A simple dirty potentionmeter in the illumination control. dismantle the LSZ to gain access to the illumination control. Spray contact cleaner or good old CRC (a little, not a lot!) into the dimmer potentiometer and then move the pot through its range to spread the contact cleaner around and clean the contact surfaces. See if it helps. It has worked wonders for me many times with older, dirty pots in many electronic items. Sometimes through the pot can be so sirty or corroded or oxidised that no spary will help forever. Then replacement of the pot is the only cure. 3. Bad connection on the 58G illumination signal (red/green wire) as it is distributed throughout the vehicle. Monitoring which lights are affected and then referring to the wiring diagram will help you find the intermittent connection. If the variation of the illumination only affects SOME but not ALL of the illuminated switches etc at the same time, then you must have a faulty wire connection in the red/green wire. Be aware that some displays (radio, climate control, instrument cluster) have a photo sensor which alters the brightness of the display based on ambient light levels. So these displays may not react as quickly to a change in the PWM illumination signal, and they may mask a rapid fluctuation of the PWM signal, which might make itself visible on eg a switch illumination, but not on the radio display. You can also test the instrument cluster illumination as follows: System test (Test No. 2):This system test facilitates simple visual assessment of the instrument cluster (pointer instruments, displays, lighting, warning lamps and indicator lamps). Selecting system test function The system test is started by pressing the left-hand button in the instrument cluster (trip recorder reset button. The button must be pressed and held with the ignition lock in "0" position, now turn the ignition lock to position "1" (terminal R radio setting) and release the button. When "tESt 1." appears in the display press the button once again, "tESt 2." now appears. After a short period of time, the display changes to "tESt 2.0". The system test can now be started by pressing the button once again. By switching the terminals, ignition lock from position "1" (terminal R radio setting) to position "2", the two-coloured indicator lamps are activated yellow and red. On completion of the system test, it can be repeated by pressing the button once more. These elements are: All pointer instruments (pointers are moved once over their indication range) All LC displays with a segment test and their background lighting Indicator and warning lamps for: High beam Oil pressure (red) (ignition lock in position 2/terminal 15) or Oil level (yellow (ignition lock in position 1/terminal R) ASC Front/rear fog lights Windscreen washer fluid level "CHECK ENGINE" EML (EPC) / MDK Coolant level Brake pad wear Tyre pressure control Cruise control Belt warning Fuel reserve Coolant high temperature Left/right direction indicators Windscreen washer fluid level Shift indicator (if automatic transmission is coded) Cruise control (Tempomat) cut-in Battery charge indicator lamp General brake warning lamp (at terminal 15) All test functions, apart from test numbers one and two, are interlocked and must be released by means of test function number nineteen. Selecting test functions The test functions are started by pressing the left-hand button in the instrument cluster (trip recorder reset button. The button must be pressed and held with the ignition lock in "0" position, now turn the ignition lock to position "1" (terminal R radio setting) and release the button. Once " tESt 1. " appears in the display the required test can be selected by pressing the button. " tESt 2. " " tESt 3. " " tESt 4. " etc. now appear in the display. After a short time, the display changes to " tESt x.0 " (x stands for selected test group), by pressing the button once again, it is possible to switch to another test in the test group or, as in the system test, start the respective test. If the test is a locked test (test 3 to 21) the lock is released with test 19 by pressing the trip recorder button when "_L_oFF" appears in the display. The display then jumps to test 0 so that the corresponding test group can be selected by briefly pressing the button. 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jochen 4 Report post Posted November 21, 2008 Still new to this... I am having what I think is a similar problem. My outside temp reading has dimmed and looks to also have dimmed part of the odometer display (this is on an E39, instrument display). Is the fix for this similar to what you have discussed? I'm pretty good with the mechanical side of things, but electrical scare me a little. Are you in Wellington at all? if not, is this something that most competant electricians could handle? On the E39 the dimming of the check-control display, and service indicator, and outside temp, is all due to contact problems developing between the LCD display and the circuit board behind it. Google "E39 pixel problems" and you'll see this is a world-wide common problem. It also affects E38 and X5s. There are DIY fixes but not for the faint hearted, otherwise the instrument cluster can be sent to a guy in Auckland - ask Glenn from Botany Motor Works who the guy is. Note of course that the car cannot be driven without the instrument cluster. Don't trust an electrician, you need to be an electronics repair technician to work on this fault. I'm in Switzerland :-) Quote Share this post Link to post Share on other sites
*Glenn* 855 Report post Posted November 21, 2008 Still new to this... I am having what I think is a similar problem. My outside temp reading has dimmed and looks to also have dimmed part of the odometer display (this is on an E39, instrument display). Is the fix for this similar to what you have discussed? I'm pretty good with the mechanical side of things, but electrical scare me a little. Are you in Wellington at all? if not, is this something that most competant electricians could handle? If you want you can send the cluster to me, or ring me on Monday and I can give you the Instrument Technicians details. We use Shane in Takanini (Auck) but I dont have is addy details here at home with me. Remember you cant drive the vehicle with the cluster out. And your lights will stay on unless you refit the cluster trim with the switches in. Quote Share this post Link to post Share on other sites
