[Korvo]

Alright people. Help me out. Both of my reverse lights were working, but I swapped them out for some canbus LED's. I coded them in BimmerCode and they worked perfectly for a few months. Now one of them won't light up, even when replaced with a stock bulb. I think there might be something wrong with the REM. Here's what I've done:

-Coded LED settings back to stock
-Swapped LED's. It's clearly only the drivers side that's not working as the drivers LED works in the passenger socket.
-Checked all related cables for burns/corrosion/cuts.
-Checked all fuses related to bulbs(even the five REM fuses).
-Not throwing any codes when scanned.

What am I missing? Replace the REM next? Or the bulb housing?

[Billfitz]

Since there is no left/right reverse lamp I'd break the connection on the socket to the drivers side bulb and run a wire from it to the supply on the passenger side. Since the current draw is far lower with LED that wouldn't put a strain on the passenger side wiring.

[Korvo]

Originally Posted by Billfitz

Since there is no left/right reverse lamp I'd break the connection on the socket to the drivers side bulb and run a wire from it to the supply on the passenger side. Since the current draw is far lower with LED that wouldn't put a strain on the passenger side wiring.

I considered that, but if the LED's are what caused the issue, it might happen again. I'm going to try disconnecting the battery. Should have done it earlier.

[Billfitz]

I doubt the LEDs caused the problem. If so this topic would have popped up years ago. I also doubt that disconnecting the battery will have any effect, other than your having to reset your clock.

[Korvo]

Originally Posted by Billfitz

I doubt the LEDs caused the problem. If so this topic would have popped up years ago. I also doubt that disconnecting the battery will have any effect, other than your having to reset your clock.

Correct and correct. Didn't do anything. Now have to reset clock. There's no power coming to the connector. Cables look good. Might just order the rear module.

[Korvo]

What I really need to know is how would the REM fail to send a signal to only one bulb. Is wiring the more likely culprit?

[Billfitz]

You need to check the output wire at the REM to know.

[Korvo]

I'll buy a multimeter tomorrow and check that. I bet tracing down which wires control the driver side will be tough.

[Billfitz]

You can find schematics at newtis.info, but they tend to be undecipherable.

[Ibo24]

Don’t you just have a short circuit?

[Billfitz]

A short circuit would blow a fuse. It would also throw a code.

[Korvo]

Originally Posted by yungming

Hi

Does it give a fault coded in the iDrive before?

BMW has a special function to cut off the circuit once it reaches the number of times of fault code to prevent further short circuit

My rear brake light as well, i thought the module was having problem and then i use ISTA+ to diagnose and reset the counter for the bulb, then it works again.

Do you have ISTA+? or what software you use for code scanning?

I didn't see any codes being thrown. I have a Foxwell 510. This is a great idea. I'll look into it. Thanks!

[Billfitz]

If it has an allowable number of short circuits exceeded fault the Foxwell will show it.

[Korvo]

So the REM is throwing a code that's related to too many short circuits. Basically, it has shut down the driver reverse light and it won't come back on. It's reached the max shorts or something like that. Seems like the only way to fix this is to buy a new REM. I'll need to fix the short first. Anyone know how to reprogram one of these, or do I need a new one?

[Billfitz]

Did you clear the code?

[Korvo]

Originally Posted by Billfitz

Did you clear the code?

It won't clear. It just comes back.

[Billfitz]

What are you using for a diagnostic tool? A fault code shouldn't come back after being cleared unless you do something to cause it, like putting the car in reverse.

[Korvo]

Originally Posted by Billfitz

What are you using for a diagnostic tool? A fault code shouldn't come back after being cleared unless you do something to cause it, like putting the car in reverse.

I was using the diagnostics page of Bootmod3. I have an NT510 but haven't really taken the time to figure it out. Does it need to be done through that?

[Billfitz]

I don't know about Bootmod 3, but I've never had a problem clearing codes with my 510.

[Korvo]

Originally Posted by Billfitz

I don't know about Bootmod 3, but I've never had a problem clearing codes with my 510.

I'll figure it out and try to get it done with the 510

[Ibo24]

Like I said in the first place, you just have a short circuit.

You either need Toolset32 or ISTA+ to remove the shortcircuit.

OBD reader won’t do the job.

[Billfitz]

If the OP has a short circuit no tool will remove it, unless said tool is perhaps a screwdriver. If he has a short circuit fault code an OBD reader won't remove it, but a diagnostic tool like the NT 510 should.