Hello Everyone,
I have been having trouble with my power locks on my TL. I was doing some research and found out that others have had a similar problem that they were able to fix by replacing the multiplex unit near the drivers side fuse box. Does anyone know the part number or the actual name of the unit? Also if anyone knows the cost for the unit I would like to know. Thank you in advance

 

HHAHAHA I thought this was someone trying to sell a "multiplex unit".
Sorry I am dumb.......

I am not sure but if you try the search button you might be able to find something on there.

 

ETL --

How about some more details about your "door lock" problem -- i've worked with the doorlocks extensively on my TL. What year is your TL?

the Multiplex unit is called:

Multiplex Integrated Control Unit (MICU) and it's actually built-into the under-dash fuse/relay box... you have to buy both at the same time, therefore, sux.

Page 22-8 of the Acura TL service manual

I believe it's called the "Fuse box Main" and it's about $187.00 on www.acurapartsoem.com

Before you go spending all that money -- tell us what's going on...

 

Oh, and I know of a multiplex unit someone can rent if they're interested... LOL

 

problems with doorlocks can be a hundred things.... fuses, actuators/lock-motors, MICU, keyfob receiver/transmitter, child saftey switch, door pin malfunction, wiring, harnesses... just to name a few

Do you hear relays "clicking" yes/no?
Do some locks lock while others don't yes/no?
Is this problem progressive or happened all of a sudden?
Any other interior electrical malfunctioning devices (map lights, dash lights, etc)?
Weird grinding or whining sounds from the doors when locking or unlocking?
Any recent aftermarket work done?
Have you checked all your in-cabin/engine bay fuses, yes/no?

 

Heres the problem:
I am able to unlock the doors with the key fob and the door switch. But I am unable to un lock any of the doors with the key fob or the door switch on both doors. Its been an on going problem. It will work for a period of time, then it will stop working, then it works again. Also when I try to lock the door with the keyfob none of the doors lock and the headlight do not flicker. But when I manually lock the doors then push the lock button on the keyfob the exterior lights flicker and the car beeps like its suppose to. I also do hear a faint clicking noice when I try to lock the door.

 

Its similar to this problem:
https://acurazine.com/forums/showthr...light=actuator

 

Also I have a 04 TL.

 

If you're unable to lock any doors with either door switch, nor the keyfob, sounds like a MICU issue (as you first posted) and you'll need that unit swapped out.

Ongoing, intermittent problem = less likely blown fuse

The fact that when you manually push with your finger each door lock down then hit the "lock" button on the keyfob and get a "beep" indicates that your keyfob receiver is functioning, the alarm system is detecting four locked doors and doing the right thing, again points to the door lock relay system in the MICU/main fuse box.

A faint clicking noise may indicate a minimally functional relay.

When you say "headlights" flicker, I think you're indicating 'Park light blink' to confirm lock or unlock visually.

If all the locks follow the same pattern (i.e. one door does something different than the others) the problem is more likely the MICU/main-fuse box (that contains the door lock relays) than it is individual actuators.

Do you feel comfortable changing out the unit on your own?

 

I dont think I can do this on my own. I will give the dealership a call and see how much they will charge. Then I will go from there. Thanks for your help

 

They'll bill for at least 1.5 hours at their hourly rate 85.00/hr I believe + cost of unit. That doesn't include diagnostics. Hopefully you'll get lucky and it's something simple.

lemme know, happy to help.

 

get the battery checked too.....sometimes the low current (when the battery is on its death bed) messes with everything.....did this occur when the car was new or did u get it used??

 

with the car off - no key in the ignition_ disconnect the + and - cable and hold them together for about a min. hook them back up and test the locks. if it still happenes replace the actuators.

 

I have the EXACT same issue where the door unlocks but does not lock. I read the description and it matches to my symptoms identically. When the doors are locked manually and I press the "lock" button, there is a beep.

We took the car into the Acura dealership and the cost is $640 + tax!!!

I would really like to do this myself and save some $$$ (plus score some points with my wife ) Can anyone give me an idea of how difficult this job is? If the Multiplex Unit is easily accessible then it shouldn't be too difficult right? Also, where can I get a good shop manual for the Acura 2005 TL?

 

Also, if someone could confirm that the multiplex unit is called the fuse box assembly on acuraoemparts.com I would greatly appreciate it! Thanks! http://www.acuraoemparts.com/delray/..._FUSE_BOX_ASSY.

 

Cinco: I'm having a related problem with the MICU knocking out the truck control my 2006 TL. What did you find out on the fuse block/MICU?

https://acurazine.com/forums/3g-tl-problems-fixes-114/2006-tl-navi-trunk-lid-wont-open-758591/

 

You can access the 2004 -2006 Manual at: http://www.hondahookup.com/manuals/?...6%20Manual.pdf

It's a scanned copy, with a few blank pages but does cover full TL maintenance.

 

Update:
I have the exact same issues with my power locks not locking via button or keyfob. The unlock works great. The extra issue this has caused is a parasitic drain on my battery. If I dont drive my car for about a day, it is completely dead. This issue has gotten progressively worse since my car began acting up with the locking issue but I should report that my car had not had the service bulletin that pertains to the fuse #7 parasitic drain on the nav display. I have since had that corrected but my car still drains the power.

The acura dealership installed the actuator in the door and the issue remained. I have since ordered this MICU and am about to install it. They said that the doors will not lock because the relay that controls the passengers door appears open and closed at the same time. This leads me to suspect that my MICU is the culprit of the faulty alarms and my battery draining issue.

Part #: 38200-SEP-A03
BOX ASSY.,FUSE $195.53
Subtotal $195.53
Shipping Charge $15.64
Handling Charge $3.95
Sales Tax $0.00
Total $215.12

My next step is to install this in my car. Does anyone have any advice on how to do this? Unfortunately, it is the fuse box inside the car, not under the hood. It would be far too easy to have to change out an easily accessible part opposed to one buried under the dash in little to no access. Anyway, hope this update helps some of you. I will let you know how my car works afterwards.

 

Also, I am noticing a slight difference in part numbers from the previous post pointing to A04 and the one I posted A03. The dealership is the one who gave me this A03 part number on paper after the diagnosis to order. I am wondering if these are the same parts just different versions? The price is different. hmm.

 

Update:
Replaced the fuse assembly!

My door locking issue is now resolved. It locks and unlocks correctly!

The job of replacing it was a pain in the ass but doable. I basically removed the kick panel and the cover under the steering wheel. After that I started disconnecting all the connections on the front of the fuse assembly, 2 on the side, and then I unbolted the top and bottom bolt. I was able to pull the fuse assembly out just enough to see the 8 connectors on the backside. Took those off and reversed process for installation. Gotta take your time doing this...only took me 2 hours and the book states its 3.5 hours. Im sure this is so the dealership can rip you off nicely. Anyway, my parasitic draw issue is still present. I just read a thread on HFL issues so I'm recharging my battery and will see if disconnecting the HFL will fix that issue.

 

Hey, all. I haven't posted on AZ for a while but I've been having a problem with my locks on my 2004 TL for quite a while and it sounds a lot like the problems described here.

Probably a year or so ago my "lock" function stopped working from the remote and the door buttons. Being lazy, I just worked around it and locked the doors manually whenever I needed to. (The unlock works from the switches and the remote) More recently I had a problem where many other functions would intermittently stop working. The turn signals, high beams, HFL, and seat memory would stop working. It seems like it may be related to water, as it happened a couple of times when it was raining. I checked the sunroof and windsheild cowl drains and they are not clogged. I don't notice any water on the carpet, either. After a couple of hours everything starts working again (except the door locks). I did notice water on the carpet on the passenger side once a while back. Is there anything on that side to be concerned with?

Are these other functions controlled through the MICU? I don't want to replace the MICU and find that it's not the problem, or have it return later because the MICU gets damaged again.

Also there are a couple of part numbers for the MICU. When I put my VIN into Acurapartswarehouse.com it comes up with 38200-SEP-A01. Anyone know what the differences is?

Sorry for the long post. I've owned my TL since new and it has been extremely reliable. In nearly 11 years I've spent a total of $400 on repairs, excluding routine maintenance! I'd like to keep it as my DD for a while longer but if it starts to have electrical problems I'm not sure I want to deal with that.

Thanks for any advice you can offer. I always find the community here to be very helpful.

 

I meant to add that I had replaced the driver's sid actuator when the lock problem first started. That had no effect on the problem.

 

I've also replace the MICU, parts number 38200-SEP-A01, the door lock problem is gone, but then the ABS light and seltbelt light are on, does anyone have the same problem, or the MICU needs to be recoded or something?

 

just brought it to Acura and they told me I probably install the MICU in wrong sequence or something loose. Guess I'll have to take it out to inspect. Is there any sequence I need to follow when putting those plugs back?

 

Resurrecting this old thread. I have the exact same symptoms (doors will all unlock, but not lock), so I went ahead and ordered the MICU. I have the service manual, but I am wondering if anyone who has done this has any tips or suggestions on how to do it before I get started. Thanks!

 

did you need to reprogram?