2002 Acura TL

BEFORE
I had cleaned my interior with a cleaning solution that was a bit harsh which had caused my driver's side window master switch buttons to turn white. I purchased a replacement unit from eBay and went forward in taking off the door panel to replace it. During the install I never disconnected the battery terminal (I know.. stupid me)


AFTER
After all connections were made, the following issues were noted:
1) The master switch's window buttons did nothing
2) The lock button on the driver side does nothing
3) The puddle light is dimmer than the passenger side
4) Security system does not set when I double click the remote

I had taken the car to the dealership and the technician noted that to further
diagnose he thinks the passenger side multiplex unit ($409) needs to be replaced. But he was not sure if this would solve all of the problems... so instead of them started changing x number of parts... I took the car back and paid them the diagnostic fee.

I tried to put back the original master switch and still having same problems...

So guys.. please help... anyone know what this multiplex unit does? And there seems to be two of these... one on the driver's side and one on the passenger's side...

Anyone have other suggestions on what I may have done to cause this total mess :-(

Any help would be greatly appreciated!!

Thanks!

 

What the hell is a multiplex? Is that like a flux capacitor?
Check all your fuses and switch around some relays.

 

Stay away from harsh cleaners - esp on TL.
The TL leather is coated split grain and wears fast.
Use of warm water is your best bet and only damp rags.
Total mess it is.
Replace and reseat fuses.

 

Supposedly a multiplex is a body control module... I just downloaded the service manual so I'll look more into it tonight.

 

Its the fuse panel. The TL (as with most modern cars) the Fuse panel is MORE than just a fuse panel. It does controlling of different things, sends signals etc...

 

I can't help with your initial question, but Aerospace 303 is an excellent cleaning product for the interior.

 

Like some of the other guys were saying the multiplex is a "body control module" controls keyless entry, door lock functions, interior lights, etc... The reason we have these is to simplify the electronics in a car, and to reduce wiring, which saves Honda money, and saves weight, giving you a tiny bit more not noticeable power.

I cant remember but you might get away by finding one in a junkyard. It's the fuse box as someone mentioned on the drivers side. And I believe the same thing on the passenger side.
Sure removing the negative cable might help. Likely it wouldn't because you dropped the cleaner onto the switches, which send on/off signals to the multiplex probably shorting it out internally.
You may have to reprogram your keyless entry fobs.
Oh and have fun pulling out hte multiplex, it's a pain to remove from my memory.

 

Thanks guys for all the help. So I've been reading in the 99-03 Acura TL Service Repair Manual and there looks to be 3 multiplexes in the TL. Drivers, Passengers and within the Master window switch. I looked at the part #'s of the master switch I had replaced for my original one with and it looks like the 99-01 and the 02-03 have different part numbers! Perhaps this master switch caused a short because it was the wrong part for my model year car. So.... I've ordered a master switch from eBay from a 2003 TL premium and ordered (like the dealer tech mentioned) the passenger side multiplex unit (again the 99-01 multiplex unit is a different part # than for the 02-03 model year). Once these come in, I'll install them and get back to you with the results!! I hope the issues are alleviated!

Acura part cost:
Master window switch - online parts $127 -- eBay $15
Passenger side multiplex - online parts $279 -- eBay $30

 

Soria -- yeah thanks! I'll def. going forward use automotive approved interior cleaning products. Lesson learned!! :-)

 

Its been a few weeks since I posted about my issue. I wanted to give some updates.

I received the driver's side window master switch (which is also a Multiplex unit -- remember our TL's have 3 of them -- Locations: Driver's door, Driver's side fuse panel and passenger's side fuse panel)

 

I took out the glove box and the lower portion of the dash (few screws and just plastic clips). Before any work began, the battery had been disconnected :-) The ONLY plug connected to the passenger side multiplex unit it the green one, I unplugged it.

 

The multiplex unit is held on to the fuse panel by pressure tabs, start at each corner and the unit will slowly come loose. It will take some pressure, so dont worry if you need to use a little force. I took out the faulty one and replaced it with a eBay sourced one.

ANother picture of the original passenger side multiplex unit:

 

After these two parts had been replaced. I am happy to report all of my problems have been solved!!! :-)

 

Lastly, this is what the inside of the faulty passenger side multiplex unit looks like.
After some electronics testing with a EE friend, we determined that the Q11 controller chip and one of the caps had faulted. The EE friend was impressed by the simplicity of the circuit design Honda employed (I shook my head and shrugged... hehehe)

Anyways, thanks everyone for all of your help. I hope if someone comes across a similar problem, this thread should help them out.

 

Well done sir. Congrats.

 

thanks! I'm just glad to have the car back to normal.