hikaps14

Hi,

I have 2001 Honda Civic EX coupe. Since yesterday evening its having a weird problem.

• ds"BRAKE" light on dashboard stays on.
• dsCentral lock stopped working the same moment
• dsCruise Control also not working.
• dsAC is also not cooling

When it happened first time yesterday, I hit the brake couple of times and the e-brake too. suddenly the brake light went off.For some time BRAKE light disappeared then Central lock started working. But now its constantly switched on.

I have checked the rear brake lights and they r working fine. Brake Fluid is up to max.

Looks to be some electrical circuit issue or bad fuse.

Has anyone faced this issue before ? Please guide me. Is there something very serious and needs to be taken care immediately.

hikaps14

I went to NTB for inspection. NTB guy told me that there must have been some problem with Break switch because he pulled the e-brake couple of times and BRAKE light was gone.

Finally, when I collected my car from NTB I saw the BRAKE ligt again on dash. He told me that he would need to change the e-brake switch and he needs to buy it from Honda dealership.

What do you suggest experts. Is there anything I can do?

99blackcivicSi

there are 3 things that cause that light to come on...e brake switch, low fluid sensor in the MC, or the MICU taking a ****.

unplug the MC sensor if the light is still on unplug the e brake switch light is still on good bet its the MICU

lazlong

Or you have something stuck between the sensor and ring at the wheel.

Or a valve has gone bad in the ABS/proportioning valve module. Regular brakes will work, you just won't have ABS.

99blackcivicSi

wrong

abs failure is on another indicator what i posted are what causes that light to come on.

lazlong

My bad, I realize now it's the BRAKE not ABS light.

Along with the switch, sensor, and MCU it could be a short/open but, I doubt it.

fleabag

electrical issues.. try fixing/checking every electrical ground you have.. Could be related to the ground for the brake lights in the trunk or that something is getting overloaded somewhere..

hikaps14

Hi,

I am a bit of novice in this. Do we have any link which explains me on how to do it.

lazlong

MC sensor:


Pull the top off the center console (it just pops off):


Brake switch (little white plug):

Sorry about the fuzzy pics, crappy phone cam.

The MICU is integrated into the under-dash fuse box. To replace it you would have to get a whole new under-dash fuse box.

hikaps14

Sorry for extreme late response. I was busy with couple of other things and couldn't update you.

I got all my under dash and under hood fuse check by mechanic.
Brake oil also checked and tried to fill a little bit to top off.
Mechanic checked for 30 mins and couldn't make out much. He told that the 2 A/c fans are not switching on when a/c is switched on. He told that he would now need to check the relay and all wiring because there seems to be some short somewhere.


Current Situation:
"BRAKE" light on dashboard,A/c, Cruise, central lock not working, Wiper not working at level 1. Wiper works at level 2-3

I am not sure how to proceed now. Should I go to Honda dealer ship for problem detection. Once we find the exact issue , I can go back to mechanic and get it fixed. What do u recommend ?

99blackcivicSi

soundslike the MICU since those are all controlled by said unit

hikaps14

How to check MICU and its various fuses ? Still, I don't understand why the mechanic couldn't find the problem while checking all the issues.

Do I need to replace whole micu? Whath would be cost and best place to get it fixed. Is it advisable to reach Honda dealership in any case ?

It Wasn't Me

I'd just replace it. (the multiplex control unit, I mean) They're fairly inexpensive, even less if you buy a used one from a parts car.

If that doesn't fix the issue, post back.

Rocky13

Did replacing the MCU fix the problem? .... the same thing happened to my gf's 2001 civic .... the first stage of the wipers, AC, and the open door alarm all stopped working at the same time ...as well as the brake light staying on...I had a local shop check the entire brake and AC systems and he said they are fine ..... He wants to replace the AC control unit for $200 bucks .... Is that the MCU?

hikaps14

Well,

I have been having a tough luck till now. I recently checked with a honda Dealer.

He was asking $920 for MCU + labour + $190(diagnostic). Thats certainly out of my budget. Honda were calling MICU as ECM. I don't know if thats the same thing or they are just ripping me off.

Don't know if I can find any cheap local shop to fix this. I have tried a few and none could find the issue.

Does anyone know any good electrical shop in dallas, who can fix this.

It Wasn't Me

A brand new MCU is only $129.28 + S&H and is easy to replace yourself. They're a lot less expensive if you buy a used one.

http://www.hondaautomotiveparts.com/...IT+%28CABIN%29

Go to that site's homepage and put in your cars info. The price should be the same, regardless.

hikaps14

Thanks for all your help. I checked it for my 2001 Civic coupe EX automatic and it comes out to be 142.57 +S&H.

I went to autozone today and they were not able to pull up MICU part.

I can buy that but I can't do it on my own.I am completely a novice and have no instruments at all. So I need to get it done by some mechanic.

I got it checked with local guy and he didn't know anything about MICU. So went to Honda dealer. Before doing any diagnostic I asked them about MICU cost. They told $920 and they called it ECM. I will try another dealer ship soon.


I spoke to Firestone on phone and they also don't know anything about MICU.

Though I understand, you may be 100% correct in identifying a faulty MICU, I want to get it verified, before buying and get it replaced.

In the meanwhile, my car charger 12v has also stopped working.

Is there any electrical company/chain, who specializes in doing this kind of stuff. I am in dallas.

It Wasn't Me

The MCU is built into the fuse box that goes under the driver's side of the dashboard. It's all one unit.

ECM/PCM is not the same as the MCU. The ECM/PCM (more-commonly known as the ECU) is under the passenger side of the dashboard, behind the glove box, and is a helluva lot more expensive than the MCU. It's also "the brain" for everything, but the MCU is what handles a great deal of the electrical stuff. If the MCU is wonky, a number of things will not work as they should.


You should get one of these: http://www.helminc.com/helm/product2...C01&itemtype=N

Well-worth the cost and will help to eliminate any guesswork.

Rocky13

I ordered a new MCU online for about $160 and changed it myself. Took me 1/2 an hour and everything immediately started working again. The only thing advice i would have for anyone about to do this themselves is make sure you order the right MCU for your transmission. There are diffrent ones for each..and label each plug with a letter or number for each port when you disconnect the old one...It made putting the new one in a snap.

It Wasn't Me

Glad it worked out for ya.

Thanks for the update.

cwmalo2

Any advice?

2001 Civic EX 4AT, 98K miles

I experienced the same problems as above, in this order:

- AC stopped blowing cold air
- BRAKE light came on, stayed on
- Power locks stopped working
- Intermittent wiper and dome lights stopped working

Based on the information I found online, I ordered and replaced the MCU. Replacement MCU purchased new from Majestic. All problems have disappeared with the exception of the AC. Still not blowing cold, although it does sound like "something" is happening. Can hear a difference in blower output with AC vs. off. No AC problems before the above started (all within a few days of eachother).

Any ideas? Any places to double check/troubleshoot?

Thank you very much, this forum has been extremely helpful.

It Wasn't Me

Is the compressor activating? What are the fans in the engine compartment doing?


A. The A/C condenser fan does not run at all. (but the radiator fan runs with the A/C on)

B. Both fans do not run with the A/C on. (but the A/C compressor runs with the A/C on)

C. The A/C compressor clutch does not engage. (but both fans run with the A/C on)

D. A/C system does not come on. (both fans and the A/C compressor do not work) ; heater is okay.


If you're referring to symptom D, it's probably the A/C pressure switch that is causing the problems.


Check for HVAC DTC's to verify the problem.





From the FAQ's...

cwmalo2

Thank you for the response. I checked out the fans this moring:

Both fans run with AC on, both turn off when AC off. Engine probably not warm enough for radiator fan to kick in.

Compressor appears to be engaged although it is tough to see down in that area. Anything I should be looking for to verify the compressor is engaged? When I pres the ac button in the cabin, I can feel a drag on the engine & see rpms drop. "Feels" like it did before the cooling issues started.

Heater works perfectly.

I did the HVAC DTC scan, initially came up with a code 9 (air mix control linkage). I checked alll underhood fuses and drove the car around a little. I rechecked the HVAC DTCs and no codes flashed. After driving around with AC engaged, I couldn't tell a difference in temperature between the two underhood ac lines. Maybe need more refrigerant?

I am concerned that whatever is wrong with the AC fried the original MCU, causing the other problems. I don't want to fry the new MCU with the same issue.

Any ideas?

It Wasn't Me

Those are the two fans that I was referring to; the A/C condenser fan and the radiator fan.

You should be able to hear it click and visually see that the clutch has engaged.

It's possible. Have you had the pressure checked?

I doubt it's why the MCU went ****. A fuse would have likely blown before the MCU suffered any kind of damage.

chulow

TO ALL THATS DEFINITELY THE PROBLEM, THE MCU IS BAD, THE ONLY WAY TO FIX IS TO REPLACE THE FUSSE ASSEMBLY BOX.

YOU CANNOT PUT A DIFFRENT ONE ON IT, SOME FUNCTIONS WILL WORK AND SOME WONT, SO DONT HALF *** IT TRYING TO PUT ONE FROM A DIFFERENT MODEL CAR...
SAVE YOURSELVES A HEADACHE...