Door handle lamp constant ON

[Q70sGuy]

Keeping things interesting around here

I have the door handle welcome lights on constantly - they come on as soon as I do anything (unlock, approach) and they don’t turn off until the car is off and the battery saver kicks in (30 minutes I think ). No other light stays on.
I even turned off the welcome light feature in the scanner (consult style) yet it continued to come on

From my understanding, likely the BCM transistor for that pin is busted and stuck on (constant ground), it I have a short to ground somewhere. Just wondering if anyone else has had this issue and solved it

[VStar650CL]

The Power Saver supply and BCM output to both lamps is common, so it isn't impossible you have a short to ground in the latter and not a bad BCM. The BCM output will be open-collector, so a short to ground won't hurt it. The way to find out is to unplug M123 (40-pin white connector) at the BCM and then ohm from the Black/White wire at either handle to ground. If it shows continuity then the problem is in the wires, if it shows infinity (OL) then the BCM output is melted.

[Q70sGuy]

Thanks good info. I’ll read up on the power saver supply. Do you know if a used BCM be reconfigured ? The fsm said not to use “write configuration” except on a new BCM so I assume not.

[VStar650CL]

The problem with used BCM's is the fobs, the latter mate for life. To employ a used BCM you need new fobs, to employ used fobs you need a new BCM. Used + used = won't program. Other than that, as long as the p/n's match, it is generally possible to reconfigure a used BCM to work in a different ride.

[Q70sGuy]

Oh man that’s annoying then. BCM ms are not cheap no wonder the last owner didn’t bother to fix it.

I do wonder if electronic repair shops couldn’t repair it if it’s a broken transistor or something like that

[VStar650CL]

I doubt it. Almost all the relay and lamp drivers in a Nissan/Infiniti BCM are IC chips, not discrete transistors. The one time I did repair one (an R52 Pathfinder with a shorted blower relay driver), the chip turned out to be an Infineon part number I had to obtain from Hong Kong because none of the parts distributors here stocked it. I also had to use bismuth solder to make a clean extraction, because the BCM PCB was 7-layer with a crapload of internal copper that was very hard to heat up. So it may be possible if you really know your stuff, but it won't be easy even so.

[VStar650CL]

PS - I've never had the slightest problem with eBay keyfobs as long as they claim equivalence to the OE part number and they say new and not used or refurbished. A pair of those and a used BCM is probably your best bet for getting out cheap.

[Q70sGuy]

Damn, I certainly would never attempt it with my zero experience at circuit board work but if it’s that complex then a pro could probably cost more than a used BCM and new keys, and with no guarantees !

Anyway could still be a wiring issue so I’ll find out in the summer
Thanks for your insight!

[VStar650CL]