Transmission Warning Light Comes Up When Pressing the Brake

Welcro · 04-08-2021, 01:25 AM

Hi all,

I have a '05 E90 Pre-LCI with N46 Engine and Automatic Transmission (ZF). Every time I press the brake the yellow transmission warning light will come up and will disappear after the brake is released.

I use ISTA/INPA to check the fault code and here is what I got:
51AE: No message (brake light switch), receiver EGS, transmitter DME-DDE

I already changed the brake light switch (Part no.61316967601) but the problem still occurs with the same fault code.

Anyone used to has this problem? And how you fix it? Any suggestion would be really appreciated. TIA!

Welcro · 04-13-2021, 02:30 AM

Just want to update so this thread might be useful for someone in the future. The problem was from the bad DME, switch to the new one and everything is fine.

blingers · 04-14-2021, 02:11 AM

curious to know what caused the DME to fail. was it from a battery disconnect?

Welcro · 04-19-2021, 06:57 AM

No clues and also want to know to prevent this from happening again. I unscrewed and open the old DME up to check for any water damage or any sign of burnt parts on the green board, found nothing, everything is in mint condition.

04-08-2021, 01:25 AM	#1
Welcro New Member 6 Rep 28 Posts Drives: E90 Join Date: Sep 2018 Location: BKK, Thailand iTrader: (0)	Transmission Warning Light Comes Up When Pressing the Brake Hi all, I have a '05 E90 Pre-LCI with N46 Engine and Automatic Transmission (ZF). Every time I press the brake the yellow transmission warning light will come up and will disappear after the brake is released. I use ISTA/INPA to check the fault code and here is what I got: 51AE: No message (brake light switch), receiver EGS, transmitter DME-DDE I already changed the brake light switch (Part no.61316967601) but the problem still occurs with the same fault code. Anyone used to has this problem? And how you fix it? Any suggestion would be really appreciated. TIA!
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04-13-2021, 02:30 AM	#2
Welcro New Member 6 Rep 28 Posts Drives: E90 Join Date: Sep 2018 Location: BKK, Thailand iTrader: (0)	Just want to update so this thread might be useful for someone in the future. The problem was from the bad DME, switch to the new one and everything is fine.
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04-14-2021, 02:11 AM	#3
blingers Second Lieutenant 25 Rep 231 Posts Drives: Pre-LCI 130i Join Date: Jun 2010 Location: sydney iTrader: (0)	curious to know what caused the DME to fail. was it from a battery disconnect?
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04-19-2021, 06:57 AM	#4
Welcro New Member 6 Rep 28 Posts Drives: E90 Join Date: Sep 2018 Location: BKK, Thailand iTrader: (0)	No clues and also want to know to prevent this from happening again. I unscrewed and open the old DME up to check for any water damage or any sign of burnt parts on the green board, found nothing, everything is in mint condition.
	Appreciate 0 Quote