Electrics MICU in Sleep Mode

[hapzuk]

Hi,

Hoping someone would be able to give me some advice on the MICU when it is in sleep mode.

My Civic has been through quite a bit in terms off getting fixed for a battery drainage issue.

1st diagnosis) Honda replaces battery
outcome) Battery drainage remains the same

2nd diagnosis) Honda replaces MICU
Outcome) Stated the first MICU didnt go into sleep mode, the new MICU does. however there is a "secondary" drain

3rd diagnosis) Honda says the HFT is causing the secondary drain


my question is, if the new fuse box is going into sleep mode how is the HFT causing a drain? Doesnt the fuse box going to sleep mean the HFT is not getting power?

[spacecadet]

Originally Posted by hapzuk

Hi,


my question is, if the new fuse box is going into sleep mode how is the HFT causing a drain? Doesnt the fuse box going to sleep mean the HFT is not getting power?

The micu problem that caused the recall on 2008 cars is to do with cpu within the micu that control various functions of the car not going into sleep mode. It was actually a firmware bug. So the micu itself was consuming far too much current causing the battery to go flat in 4-5 days.

The micu doesn't control everything on the car, so if for example the switch for the boot light was faulty such that it stayed on when the boot is closed, you would observe a separate current drain.

Dealers monitor current drain using an ammeter and if its too high, will typically narrow it down by pulling fuses one by one until they find the offending circuit. In this case they have presumably found the HFT to be the cause. In that case the problem is completely independant of the micu.

I am a bit suspicious of your dealers story. They may have just changed the micu because thats a known potential issue without doing any real diagnosis at all. Then they found that the micu wasnt the reason at all and they had to look elsewhere. Changing the battery was a pretty dumb thing to do as well. So many good battieries get chucked each year because many think flat battery = bad battery. Nine times out of ten this is simply not true. Hope they are not making you pay for it. Now that are giving you some bullsh*t story that your micu was faulty too to justify their random parts swapping exercise. Call me a cynic, but I have seen lies like this come out of dealers time and time again. I no longer trust anything they tell me at face value.

[hapzuk]

I totally believe the issue was the HFT in the first place. I had mentioned to them as this maybe a possibility causing the issue. Really I should have disconnected it myself and tested.

They charged me for the battery - £85, I've argued the case with them but they said "no you did need a battery", the diagnostic told them so according to them. I know I didnt need a battery.
The car would go flat after 48 hours with the old battery, and it also went flat aftr 48 hours with the new battery. No improvement with the new battery HENCE it is NOT the battery.

They changed the MICU, believing this was the issue.
So i'm thinking I should perhaps ask them to give me a full report on what they have changed and why and what their improvements were once they changed the MICU.

So if the MICU has improved the issue, then easy test would be to test that the battery shouldnt go flat after 48 hours, but maybe after 72+ hours.....
If thats not the case then they havent improved anything.

They wanted £270 for replacing the MICU (after many complaints to Honda) they initially wanted £450.

I'm hoping they are ready to give me a full engineers report and not just a receipt for a new MICU + labour

[spacecadet]

Ask them to tell you exactly what were the diagnostics they did to prove the battery needed changing?

[hapzuk]

Thanks, I will do when I pop into the dealership tomorrow.

[DerChef]

Originally Posted by hapzuk

I totally believe the issue was the HFT in the first place. I had mentioned to them as this maybe a possibility causing the issue. Really I should have disconnected it myself and tested.

They charged me for the battery - £85, I've argued the case with them but they said "no you did need a battery", the diagnostic told them so according to them. I know I didnt need a battery.
The car would go flat after 48 hours with the old battery, and it also went flat aftr 48 hours with the new battery. No improvement with the new battery HENCE it is NOT the battery.

They changed the MICU, believing this was the issue.
So i'm thinking I should perhaps ask them to give me a full report on what they have changed and why and what their improvements were once they changed the MICU.

So if the MICU has improved the issue, then easy test would be to test that the battery shouldnt go flat after 48 hours, but maybe after 72+ hours.....
If thats not the case then they havent improved anything.

They wanted £270 for replacing the MICU (after many complaints to Honda) they initially wanted £450.

I'm hoping they are ready to give me a full engineers report and not just a receipt for a new MICU + labour

I feel your pain mate I had nearly 4 years of flat batteries, scared stiff of leaving my car in an airport car park ect.

What helped me was I got an AA report of current draw when the car alarmed and supposedly went into sleep mode.

Honda totally useless replaced batteries with ones with a LOWER AmpH rating

I initially thought the issue was alarm but yes towards the end I was starting to think it was the HFT

[tamandlee]

Hi eveyone, I was just looking to see where to post my battery question when I saw this thread and I have the same issue.

My better half drives the car and she has 3 days off work at a time, if she hasnt driven the car for 2 of those days it wont start on the third. Had battery checked by an indy supplier and been told its fine and advised to charge it and avoid short trips if possible. Did this and still have a problem. I was going to ask if an indy car electrician would be able to check the Civics systems to the same extent as the dealers. The reason was that they seem to be very complicated and if you know nothing as I do also very specialised.

So in short, would I be as well to go to an indy or should I go direct to Honda, after hearing all the horror stories re dealers I might be as well with an indy.

Oh sorry, the car is a 57 plate 2.2 diesel.

Any views??

[mpn_daedalus]

Would be easy enough for an indy car leccy to measure any power draw by units.

Not sure how easy or otherwise it is to change units though, whether they're just 'plug and play' or whether they need configuring.

Sent from my Sony Xperia S using Tapatalk 2

[DerChef]

This is not going to be a popular but there is only one way to sort this problem out in my humble opinion/experience.

1. Drive to used car dealer

2. Take keys out of ignition for the last time.

3. Walk to his office

4. DONT LOOK BACK.

[mpn_daedalus]

Originally Posted by DerChef

This is not going to be a popular but there is only one way to sort this problem out in my humble opinion/experience.

1. Drive to used car dealer

2. Take keys out of ignition for the last time.

3. Walk to his office

4. DONT LOOK BACK.

5. Buy another Civic as the chance of having two faulty ones is slim

Sent from my Sony Xperia S using Tapatalk 2

[DerChef]

Originally Posted by mpn_daedalus

5. Buy another Civic as the chance of having two faulty ones is slim

Sent from my Sony Xperia S using Tapatalk 2

I would not have trusted another 8th gen. "Fool me twice ect" When I saw the price of the 9th gen and the shocking trade in price I got for my 2008 EX Gt 2.2 I decided me and Honda needed the divorce courts.

I saw one of their lawn mowers the other day that looked quite nice though

I think I am getting off topic and this does not help the original poster. I am no auto electrician but towards the end I had to keep my car in a locked/alarmed garage with the car its self unlocked/unalarmed. This was after I had 2 new MICUS fitted in 2010 in the space of three months suggesting Honda did not get this first time or second for some owners.

[hapzuk]

Hi,

Mine ended up being the hands free.
Once disconnected the issue of drawing current went away.


The Bluetooth wasn't working anyway, so I'm not missing anything with it disconnected.

[tamandlee]

Glad you got it sorted, ours hasnt got HFT and we went out to it earlier and its flat again!! Bring back the Alfa, we bought a Honda as they were supposed to be reliable!!!