2018 Honda Accord Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I have a 2019 Hybrid Touring, in which I installed the OEM ambient lights (very subtle effect), puddle lights (disappointing) and aftermarket illuminated door sill covers. Last mod I did was installing additional LED lamps in the upper rear corners of the trunk to bring a bit more light in there.

When I had installed those additional bulbs, connected in parallel with the OEM trunk light, everything worked fine. However, when I popped the lid the next time, there was no light in the trunk, and the interior lights, puddle lights and door sills don't work either. None of the fuses in the two fuse boxes is labeled anything remotely like "interior lights", and all of those that have anything to do with Option or the like seem to be OK. Can anybody point me to the right fuse, please? Any other ideas of what might be wrong?

Thanks!
 

·
Super Moderator
Joined
·
1,554 Posts
It does sound like a fuse, unfortunately as you have found the manual doesn't do a good job of identifying the fuses... their use of abbreviations are of no use to owner's. :sad:
 

·
Registered
Joined
·
3 Posts
Discussion Starter #3
I got it sorted, though not solved. After two more hours of googling did not produce the least bit of useful information today, and the "busy" techs at the stealership did not call me back either, I decided to pull and inspect every single fuse. When I was done with the engine compartment fuse box (without finding any blown fuse), everything was back on! My head under the hood, I have no idea after which fuse the lights came back on, of course. I did not check function between fuses.

So all I can say at this point is that it must be one of the fuses in the engine compartment box. And not one of the combo fuses, since I had pulled those in the morning already. When I have some spare time on my hands and feel adventurous, I may try and narrow it down a lil more.

It also remains completely unclear whether the apparent correlation with my installing the additional trunk lamps is a red herring, i.e., pure coincidence, or the small additional current draw exposed a fuse that was not seated properly. I hate it when things don't make logical sense, because that means they can come back at any point. And they most likely do that at the least convenient time!
 

·
Super Moderator
Joined
·
1,554 Posts
Glad you got it sorted... hopefully it will not return.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #5
Well, it did return. But I think I still got it sorted. I also posted this over on the other forum.

In the event anybody runs into a similar problem and uses forum search, here what I have meanwhile found out: There does not appear to be a dedicated fuse for the interior, puddle, vanity and ambient lights. They seem to be controlled by an ECU, which must sit behind one of the cryptically labeled fuses in the engine compartment glove box.

After I had pulled and inspected every single fuse in that fuse box and then opened the driver door, all those lights were back on. So I suspected one of the fuses had a bad contact. But the next morning, the lights were off again. I pulled every fuse once more and looked at the lights after re-seating each one. Nothing. Only when I closed and re-opened the driver door, the lights came on. Until the next morning. Da capo!

So I suspect the module tests the resistance in the circuits before going to sleep, or at some other time when the respective circuit is not powered. When I plugged in the additional trunk lights (obviously with the trunk lid open and the trunk light on), they worked just fine. But those LED array bulbs must have a CANBUS resistor. When the ECU recognizes them as a too high load, it shuts those circuits down. When the fuse is pulled, the ECU reinitializes and powers the circuits, until it performs the next test. I disconnected the additional bulbs, and everything has worked like it should for over a week.

Why the module would shut all those circuits down when it detects a too high load in one of them, I have no idea. Doesn't make too much sense IMHO. But that is what it seems to be. I'll go back to my smaller, dimmer single-LED bulbs, which do not have a resistor and worked fine for over a month -- before I wanted even more light...
 

·
Registered
Joined
·
1 Posts
Howdy, all! I just ran into the same problem with my 2020 Accord Touring. I added the OEM accessory puddle lights, interior lighting, illuminated door sills, and replaced all of the interior lights with LED's immediately after purchasing the car. Everything behaved normally for several weeks until I also replaced my trunk light with the iJDMTOY LED trunk light from Amazon (not sure if I'm allowed to post links or not, so I won't). All of the lights worked normally for a couple of days and then suddenly quit today... all of the interior lights, door sills, puddle lights, and trunk light were all dead. I checked all of the interior fuses and didn't find anything blown. So... Google to the rescue, and I found this forum thread.

The correct fuse that controls the lighting ECU is in the engine compartment on the left side fuse block, position #27 (10A "BACK UP"). I pulled and replaced this one and immediately heard something clicking, so I closed the driver's door... presto, all the lights worked again. I went ahead and replaced my trunk lamp with the OEM incandescent unit to see if this solves the problem permanently. All of the other LED's that I have installed throughout the interior are CAN-bus friendly, so the trunk light is probably the culprit. Hopefully, this will solve the issue for another owner and avoid some unnecessary hair pulling, screaming, and cursing.

4454

4455


Cheers! ?
--
QM
 

·
Super Moderator
Joined
·
1,554 Posts
Howdy, all! I just ran into the same problem with my 2020 Accord Touring. I added the OEM accessory puddle lights, interior lighting, illuminated door sills, and replaced all of the interior lights with LED's immediately after purchasing the car. Everything behaved normally for several weeks until I also replaced my trunk light with the iJDMTOY LED trunk light from Amazon (not sure if I'm allowed to post links or not, so I won't). All of the lights worked normally for a couple of days and then suddenly quit today... all of the interior lights, door sills, puddle lights, and trunk light were all dead. I checked all of the interior fuses and didn't find anything blown. So... Google to the rescue, and I found this forum thread.

The correct fuse that controls the lighting ECU is in the engine compartment on the left side fuse block, position #27 (10A "BACK UP"). I pulled and replaced this one and immediately heard something clicking, so I closed the driver's door... presto, all the lights worked again. I went ahead and replaced my trunk lamp with the OEM incandescent unit to see if this solves the problem permanently. All of the other LED's that I have installed throughout the interior are CAN-bus friendly, so the trunk light is probably the culprit. Hopefully, this will solve the issue for another owner and avoid some unnecessary hair pulling, screaming, and cursing.

View attachment 4454
View attachment 4455

Cheers! ?
--
QM
Thanks for sharing your experience and how you mitigated this issue. (y)
 

·
Registered
2020 Accord Sport 1.5T CVT
Joined
·
3 Posts
Howdy, all! I just ran into the same problem with my 2020 Accord Touring. I added the OEM accessory puddle lights, interior lighting, illuminated door sills, and replaced all of the interior lights with LED's immediately after purchasing the car. Everything behaved normally for several weeks until I also replaced my trunk light with the iJDMTOY LED trunk light from Amazon (not sure if I'm allowed to post links or not, so I won't). All of the lights worked normally for a couple of days and then suddenly quit today... all of the interior lights, door sills, puddle lights, and trunk light were all dead. I checked all of the interior fuses and didn't find anything blown. So... Google to the rescue, and I found this forum thread.

The correct fuse that controls the lighting ECU is in the engine compartment on the left side fuse block, position #27 (10A "BACK UP"). I pulled and replaced this one and immediately heard something clicking, so I closed the driver's door... presto, all the lights worked again. I went ahead and replaced my trunk lamp with the OEM incandescent unit to see if this solves the problem permanently. All of the other LED's that I have installed throughout the interior are CAN-bus friendly, so the trunk light is probably the culprit. Hopefully, this will solve the issue for another owner and avoid some unnecessary hair pulling, screaming, and cursing.

View attachment 4454
View attachment 4455

Cheers! ?
--
QM
Phew! Thank you Quasi! Saved my butt, thought I blew something since the only other thread is about damaging the microswitch in the trunk latch. The only way to fix that is a whole new part :( Luckily you saved me from that.

I took a look further into why my LED versions are not working and it seems that it may be just missing a diode in line with the LED. The original has a diode in line with the bulb and also shows it on the wiring diagram. The LED bulb appears as a short in either direction to my multimeter. This likely makes the BCM think something is shorted and kills the whole circuit.

Here's the OEM bulb and diode:
4908
4909


I will try to modify the LED board with the diode and report back later if it works. The diode is labelled M1 if anyone is curious.

Cheers!
 

·
Registered
2020 Accord Sport 1.5T CVT
Joined
·
3 Posts
So I've made a modification to an LED trunk light from Aliexpress. I cut the trace on the board and soldered a diode in the same direction as the original light. I've been running it a couple months with no problems at all now. Much brighter than the original!

To do this mod:
Pop off the metal cover and pull out the white PCB board out of the plastic lens
Cut the trace going to one of the connector terminals
5114

Solder a M1 diode to the pad of the terminal and the rectifier chip, make sure stripe is on the right
5115

Put it all back together
 

·
Registered
2019 2.0 EXL
Joined
·
114 Posts
Nice! I have the same (or very similar) LED trunk light from Aliexpress. Mine triggered the interior light shut down so I ended up scraping both sides of the PCB clean and just keeping the 2 main pins, board, and plastic housing. Then I soldered 2 of these:
to it in parallel. So far so good ::knocking on my head::
 
1 - 10 of 10 Posts
Top