polocarter

Car: 2005 Civic 2 Door EX


I have been troubleshooting this issue for a few days now, lightly, when I have time. I noticed the issue 2 days ago when I used my keyless entry to try and open the door but got nothing but two flashes of the headlights.





Thought it was weird but manually unlocked the door and got in. Car turned on fine and radio, dash unit and everything seemed fine.


Didn't notice anything until I had to turn and as normal, switched on my turn signal and heard no sound and saw no indicator on the dash.


Turned around and checked a bunch of other electrical things in the car to see what was going on.


Issues:


1. Keyless entry does not unlock the doors.
2. Side door unlock rocker does not unlock/lock the door - I can hear a click from the under dash fuse box though.
3. Power window rockers do not work either.
4. Windshield wiper does work but the intermittent mode does not work (first mode)
No other power issues.


What have I done so far:


1. Checked every fuse related to the issue (under hood and under dash).
2. Removed relays and reinserted them.
3. Disconnected the + and - terminals for an entire night.




Not sure what else to do but hopefully someone has an idea as to what it could be. Please help with any suggestions. Thanks a lot.

RIPSAW

Did you check to see if you had power on one side of the fuse to ground? Hopefully, you have missed one. The MICU controls lot of these functions. However, it and other fuses combine. There are two fuses for the wipers under the dash. When I read my 2006, it appears the MICU also controls the manual operation of the wiper. Little confusing but I am no expert . Just keeping your thread on top to Ezone wakes up. He will give you some good advice. Do not just yank stuff out. Lot of times, this may just cause more problems when it comes to electronics and electrical connections.

ezone

Not until past noon, and I don't have any coffee.




I use a test light to check every fuse in both fuseboxes, not just the ones that are labeled as seemingly related. Fuses usually are connected to far more than what is labeled.

If no fuses are blown, then MICU/Multiplex unit testing would probably go to the top of the troubleshooting list.


HTH

polocarter

Thanks for the quick reply. I really appreciate it guys.


I will check all the fuses again. I was doing some research and a lot of people had some kind-of similar issues regarding power door locks and aftermarket stereos not working and they replaced the MICU and it fixed it.


I'm wondering if that is what I'll have to do. I'm dreading it as I will likely have to take it to a dealership to get it done. I'm assuming there is a short somewhere and somehow that fried the MICU...


they only thing I was wondering was... if the MICU is in fact dead, would there be other issues? or am I not understanding it. I'm assuming the MICU either fails and everything stops or MICU fails partially. Is the MICU a board or is it a chip/device?


Does anyone know the price for such a part.


Also does anyone have a diagram of what relays do what within the interior fuse box? Thanks.

ezone

MICU or Multiplex is Hondas version of a body systems computer.

Dome light, ignition key light, AC, interlock system, keyless and door locks, key in reminder beeper, wipers, washers, gauges, idiot lights and maybe more, along with communication to other control units in the car.

The MICU is built in to the underdash fusebox. If it's bad you just replace the fusebox.

Price? No. Look it up yourself. Use one of the many online dealer catalogs. Enter your VIN instead of choosing the car yourself, that should eliminate about a dozen possible choices from the list.

It's not what I consider cheap.


Test, don't guess.
Check this post/thread for testing:

https://www.civicforums.com/forums/2...ml#post4628367


HTH

polocarter

Swapped the MICU/Multiplex and still no fix. Not sure what the heck is going on. With the new Multiplex all the same issues still occur. Nothing new has occurred has been added though. Does any know if these issues are some how connected on a similar circuit?


I forgot to mention the hazard lights are not working either. Signal/Hazards are connected on the same relay though.


BTW, I replaced all the relays in the under dash fuse box, so I can rule those out as well. All the fuses are also replaced with the new MICU.


I thought for sure the issue would be fixed with a new MICU. Was very disappointed. I'm beginning to get very anxious about the issue and have a full work week ahead and I dread the thought of driving without any turn signals...


Any ideas?

ezone

You must have missed the part about "Test, don't guess."
I guess swaptronics is a form of testing though.

Anyway.....

Pick ONE item or system that does not work correctly.
Get a wiring diagram for that system.
Get a voltmeter.
Test and diagnose until you find the cause of that one systems problem.

See if any the other systems work now. If not, then diagnose each of those as separate problems.

Grounds are an important part of every circuit.



Maybe pick turn signals/hazards.
Observe more: Do the exterior front or rear park lights and head lights also have problems? Which ones? Do they all tie together?

RIPSAW

Ouu..that is $400+ of test parts. Would surely been cheaper to have got a qualified Honda mechanic to fix it. Are you sure you found the engine compartment fuse box. Signal fuses in engine bay

CraigW

iTrader: (1)

Here is signal/flasher schematic: https://www.civicforums.com/forums/a...4&d=1229192541

If you had the audio/hvac pod out make sure you connected the flasher switch connector.

RIPSAW

Craig, you shortcut to the schematic is a loop back here I think..least for me it is.

CraigW

iTrader: (1)

It does loop back, but comes up the options for attachments... at least on my PC.

RIPSAW

You're right, did not look down to see the PDF pop up on my laptop. Total of 5 separate fuses driving the signal lights at my best count..

polocarter

Hi guys thanks for the continued support on the issue.

I really appreciate the schematic for the signals. I have some time today to dig into the issue and test some more.

The MICU was actually a friend of mines and I pulled it from his working 2004 civic. So it didn't coat me a penny. When the issue wasn't resolved I just gave it back to him and put mine back in. He didn't have any issues so I assumed there shouldn't be any issues with his MICU.

I'll get back to you guys about what I find out. Going to get my hands on a voltmeter and check everything out.

Thanks again!

ntglittle

I just found this thread and am having the same exact issues on my 2002 honda civic lx. Polocarter, Did you ever find a solution to the problem?

Thanks!

Thecrazyman

I know this is a super old thread, but I'm having the exact same issue on my 2001 EX, except that I don't have keyless entry and the issues eventually fix themselves just to come back a few months later. I made a new thread the first time it happened (a few months ago) but all I got was someone asking if I had keyless entry. Halp!

ezone

Refer to reply #5 in this thread, follow the link in there to a post that details some testing of the multiplex system.


BTW, your 2001 EX is factory equipped with keyless entry, even if someone lost the remotes to it.