Body Integrated Module and LEDs

[itsAlex]

Originally Posted by EZx2

Hi, hopefully it will help here
(situation, when opening doors doesn't yield dome lights "ON", - but switch "ON position" does )

Steps to repair:
1. order new a1764 mosfet component.
2. When arrives, take your btu from under wheel (drivers side)- black box, sits inside white plastic with all wires...

3. Open the cover of unit, recognize burned component, replace
4. Install back

Good luck!

I had dome light issues so I decided to follow your steps, turned out I also had a fried "a1764" chip:



I ordered a few of those "a1764" chips from Aliexpress for about $7. I'm waiting for my new soldering kit to arrive so I can attempt to replace the IC. I'll update with results.

[pcguru2000]

Originally Posted by GuerillaZhou

They blamed the after market LED bulbs for causing the BIU to short. The tech said the car was not designed for LEDs in those places. But they actually didn't know if the BIU shorted or not. They were able to turn the DRL on and off using techstream. They said I need to pay for the replacement and install, and if the DRL still doesn't work then they would continue to figure out what's wrong. I didn't want to take the $700 gamble.

Sounds like if we want to use any kind of warranty coverage, we will need to return our cars to stock before we go in and have them troubleshoot.

<sarcastic>
I recently changed my toyota emblem to batman. I hope they don't claim that this might be cause engine damage, transmission damage, due to the possibility of batman driving it hard!

[FRSBRZGT86FAN]

Originally Posted by pcguru2000

Sounds like if we want to use any kind of warranty coverage, we will need to return our cars to stock before we go in and have them troubleshoot.

<sarcastic>
I recently changed my toyota emblem to batman. I hope they don't claim that this might be cause engine damage, transmission damage, due to the possibility of batman driving it hard!

You really are on a role.


This was when the car first came out and the BIM was getting shorted by lower quality LED swaps, it is fully within there expertise to void that warranty because of the electronics. People were even frying the BIM on head unit installs.

It is well known you should change back to stock before you attempt a warranty repair, because quite frankly in this case an LED swap is obviously the cause. Higher quality LEDs aren't polarity specific and have better quality drivers to prevent this from happening, also the newer BIM after the earlier 2014 vins seemed to assuage this issue.

[itsAlex]

Update:

I removed the old chip and replaced it with a new "a1764" and voila, I have a working dome light again!

sorry I don't have any pictures, but at the moment I'm using a Cree LED in my dome light and everything seems to be fine. It fades on and off when the doors open and close. Success!

https://www.amazon.ca/Yorkim-Festoon...LED+Bulb%2C+Fi

That's what I currently have in my dome light^. Very bright!

[UF Key Master]

Which A1764 did you buy? None of the ones I have found are the same 3 digit number below the A1764 as the component in my BIM. Also, if you don't mind, what soldering gun did you get and how difficult was it to remove and solder. The thing is so small I'm nervous about doing it.

[itsAlex]

Originally Posted by UF Key Master

Which A1764 did you buy? None of the ones I have found are the same 3 digit number below the A1764 as the component in my BIM. Also, if you don't mind, what soldering gun did you get and how difficult was it to remove and solder. The thing is so small I'm nervous about doing it.

The chips I used said "737" underneath "A1764", I'm pretty sure 737 didn't match my original chip but it worked in the end.



I bought a fairly cheap watt-adjustable soldering iron for about $30 on Amazon. Honestly the key is to keep your temperature high enough just so that it melts the solder quickly and doesn't cause damage to the chip or anything surrounding it. Most importantly, use flux! I used a lot of it just to be safe, it made soldering the new chip on so much easier as the solder flows nicely and it bonds to the metal pads and pins without you having to do much guiding.

[_kongzilla_]

Thanks @itsAlex
i did mine a while back and it worked. Got my domelights, courtesy lights, and puddle lights working again

[suzyj]

The whole part number for this dual mosfet is μPA1764. It’s labelled A1764 simply because there isn’t enough room on the top of the 8 pin SOIC chip. The numbers under the A1764 are a date code, and will vary from one batch to another

Here’s the data sheet for the part: https://www.renesas.com/us/en/doc/Do...9EJ2V0DS00.pdf

It’s a very generic dual N-type MOSFET, good for 60V and 7A. The Renesas part is obsolete, but there are hundreds of pin compatible drop in replacements by practically every MOSFET manufacturer. Key is automotive qualified, >7A Id, >=60V Vds, <25mΩ Rds(on), 8 pin SOIC package.

For example: https://au.mouser.com/ProductDetail/...5%252bIA%3d%3d

[GJR726WY]

Hate to beat a dead horse here, but I lost my driver's door courtesy light yesterday trying to replace a blown bulb ... I'm guessing it's BIU related. Is this component mentioned in this thread the same one that's used for the door courtesy lights? I'm nervous about doing a repair like this, but I'd rather at least try before I pay a dealer a zillion bucks to replace the unit and re-program everything.

[itsAlex]

Originally Posted by GJR726WY

Hate to beat a dead horse here, but I lost my driver's door courtesy light yesterday trying to replace a blown bulb ... I'm guessing it's BIU related. Is this component mentioned in this thread the same one that's used for the door courtesy lights? I'm nervous about doing a repair like this, but I'd rather at least try before I pay a dealer a zillion bucks to replace the unit and re-program everything.

I own an FR-S so I don't have courtesy lights. Do your courtesy lights fade on and off when opening and closing doors? Or do they just turn on right away?

If the driver's side is the only one not working it may not be an issue with the BIU as if the chip failed then your dome light would also stop working. Maybe check the fuses related to the courtesy lights?

[GJR726WY]

Originally Posted by itsAlex

I own an FR-S so I don't have courtesy lights. Do your courtesy lights fade on and off when opening and closing doors? Or do they just turn on right away?

If the driver's side is the only one not working it may not be an issue with the BIU as if the chip failed then your dome light would also stop working. Maybe check the fuses related to the courtesy lights?

I believe they do not fade, they just turn on. I took the dash apart here over the last week and took out the BIU. After disassembling it, nothing looks burnt or compromised. I checked all the lo-pro mini fuses I could identify in the wiring diagrams as being associated with the light to no avail. I'm stumped, I can only guess it shorted one of the wires somewhere, but I am not sure how to find that. Let alone the desire to trace feet of wire through all the looms.

[itsAlex]

Originally Posted by GJR726WY

I believe they do not fade, they just turn on. I took the dash apart here over the last week and took out the BIU. After disassembling it, nothing looks burnt or compromised. I checked all the lo-pro mini fuses I could identify in the wiring diagrams as being associated with the light to no avail. I'm stumped, I can only guess it shorted one of the wires somewhere, but I am not sure how to find that. Let alone the desire to trace feet of wire through all the looms.

This might sound dumb but are you positive you're testing with a good bulb?

Also, hopefully it doesn't come to this but it may actually be the harness behind the door panel that has gone bad. I once had an incident where an LED bulb in my license plate light went bad. It burnt the red positive wire on its harness as the bulb basically turned into a dead short. Luckily one of the fuses up front popped so not much damage was done, but it is a possibility nonetheless.

Since you've ruled out the BIU, my advice would be to use a multimeter and check for continuity between the ground contact of the bulb socket and the chassis. If there is continuity, next would be to check the +12V contact in the socket and trace it to it's fault.

[GJR726WY]

Originally Posted by itsAlex

This might sound dumb but are you positive you're testing with a good bulb?

Also, hopefully it doesn't come to this but it may actually be the harness behind the door panel that has gone bad. I once had an incident where an LED bulb in my license plate light went bad. It burnt the red positive wire on its harness as the bulb basically turned into a dead short. Luckily one of the fuses up front popped so not much damage was done, but it is a possibility nonetheless.

Since you've ruled out the BIU, my advice would be to use a multimeter and check for continuity between the ground contact of the bulb socket and the chassis. If there is continuity, next would be to check the +12V contact in the socket and trace it to it's fault.

Yes the bulb is good, If I put it in the other door it will light up normally. I'm unsure what you mean by "harness behind the door panel". I haven't investigated anything further since eliminating the BIU.

[Trap63]

Originally Posted by EZx2

Hi, hopefully it will help here
(situation, when opening doors doesn't yield dome lights "ON", - but switch "ON position" does )

Steps to repair:
1. order new a1764 mosfet component.
2. When arrives, take your btu from under wheel (drivers side)- black box, sits inside white plastic with all wires...

3. Open the cover of unit, recognize burned component, replace
4. Install back

Good luck!

Hello @EZx2, do this mosfet control ground circuit in unit? or whatelse?

I solved carry on another ground point on main harness and insert a by-pass from door open/close switch, at now all works fine. I damaged circuit of map light working for new led door.