E39 lighting upgrade problem

[mitchE30 0]

I have been upgrade E39 rear lighting from 96 to 2003,LED type park light,every thing they work ,but always check brake light when I braking,also when I star ask me to check the tail light.please help.and one more thing if the LED broken,how could I change or fix them?

[jochen 4]

I have been upgrade E39 rear lighting from 96 to 2003,LED type park light,every thing they work ,but always check brake light when I braking,also when I star ask me to check the tail light.please help.and one more thing if the LED broken,how could I change or fix them?

The light bulb monitoring is designed to monitor normal light bulbs 8tungsten filament bulbs)

Changing to LEDs changes the bulb resistance, the monitoring circuit decides the old light bulb is no longer there or dead, and shows the error message

Proper solution = change the coding of the car so that LED taillights are fitted. This switches off the light bulb monitoring message.

You can do this at BMW, or using my NavCoder software, available here:

NavCoder zip file

As for borken LED taillights, they are normally repaired by replacing the entire light assembly.

[mitchE30 0]

The light bulb monitoring is designed to monitor normal light bulbs 8tungsten filament bulbs)

Changing to LEDs changes the bulb resistance, the monitoring circuit decides the old light bulb is no longer there or dead, and shows the error message

Proper solution = change the coding of the car so that LED taillights are fitted. This switches off the light bulb monitoring message.

You can do this at BMW, or using my NavCoder software, available here:

NavCoder zip file

As for borken LED taillights, they are normally repaired by replacing the entire light assembly.

do you know how much to recode the problem?

[elmarco 56]

LED lamps draw a very small current (and therefore power consumption) compared to an equivalent bulb lamp. While checking indicator function is a legal requirement, more advanced vehicle body computers check either the resistance and/or the current draw of the lamp to tell if the bulb is working or not for other functions as well. The low current draw is what is causing your warning signals.

This has been a big problem with truck and trailer systems especially (they were the first adopters of LED technology) and commonly people have had to fool the system to use LED lamps without the dashboard signalling problems. There are more advanced systems available now but they are only relatively recent developments.

LED lamps are much more robust than bulb lamps (dependent on their design) and designed to be maintenance free for their entire life. If you have quality OEM spec parts, the LED current and quality of LED's is tightly controlled and you should never have a problem (as long as they remain sealed). Cheap chinese (normally but not exclusively) lamps commonly overdrive the LED's as they use poor quality components and getting the required light output is difficult. If this happens, eventually the LED's will burn out and you will need to replace the entire lamp, or a solder joint could crack etc. Luckily, even this is not all that likely (unless you drive with your brakes on the whole time), and they should last the length of your ownership. You will be able to see very easily if an LED is out (it will appear as a dark spot and may affect more than one).

You are lucky that you can reprogram the body computer to recognise LED's (according to Jochen's note)!

[jochen 4]

do you know how much to recode the problem?

How much what?

Time? 2 minutes

Effort? Very little

Money? DIY = free

Hassle? Bugger all

But a lot depends on your circumstances - where you are comfortable doing it yourself, etc...

[mitchE30 0]

LED lamps draw a very small current (and therefore power consumption) compared to an equivalent bulb lamp. While checking indicator function is a legal requirement, more advanced vehicle body computers check either the resistance and/or the current draw of the lamp to tell if the bulb is working or not for other functions as well. The low current draw is what is causing your warning signals.

This has been a big problem with truck and trailer systems especially (they were the first adopters of LED technology) and commonly people have had to fool the system to use LED lamps without the dashboard signalling problems. There are more advanced systems available now but they are only relatively recent developments.

LED lamps are much more robust than bulb lamps (dependent on their design) and designed to be maintenance free for their entire life. If you have quality OEM spec parts, the LED current and quality of LED's is tightly controlled and you should never have a problem (as long as they remain sealed). Cheap chinese (normally but not exclusively) lamps commonly overdrive the LED's as they use poor quality components and getting the required light output is difficult. If this happens, eventually the LED's will burn out and you will need to replace the entire lamp, or a solder joint could crack etc. Luckily, even this is not all that likely (unless you drive with your brakes on the whole time), and they should last the length of your ownership. You will be able to see very easily if an LED is out (it will appear as a dark spot and may affect more than one).

You are lucky that you can reprogram the body computer to recognise LED's (according to Jochen's note)!

I means where do I reprogram the computer?thanks to atten my silly question.and do you know how much they cost aronud.

[jochen 4]

I means where do I reprogram the computer?thanks to atten my silly question.and do you know how much they cost aronud.

1. BMW dealer

2. Independent BMW specialist with BMW software

3. Using my NavCoder software.