It's been three months and my car is running fine despite S. Keith's doubts about the method's validity. It is true that if you have other problems this method will not work or will not over a long period. But if everything is working properly and the main battery pack has discharged from lack of driving, this will do the trick.

 

My mom took the car to Honda to have it looked at. The Tech's report states that code 1570 came up. the report also says that the technician inspected connections, reset MCM, and tested voltage at 10 Pin out. all were OK... he recommends we replace the Motor control Module 1.5 and re-test... at $4300.

Before she took it to honda, the red battery light would turn off while driving and come back on at idle, but now it just stays on all the time.

My dad went out and got the 12v battery replaced today. The car starts fine but the issue remains.. oh and i should mention that he tried the coast-turn off-turn back on trick to no avail.

its hard to justify spending $4300 to repair a 10 year old civic... especially when the battery likely will need to be replaced as well (another $3000).

cruddy situation

 

First, the dealer is likely full of ****. P1570 is a gross imbalance in voltage taps. It's likely the battery. Second, you can get a replacement battery for far less. Never consider a Honda battery. Bumblebee and Hybrid Revolt sell replacement packs that are far superior to Honda replacement packs. They should run $1,700-$2,100 depending on the desired warranty.

"battery light turns off while driving but comes on at idle" - another sign that the pack is so far out of balance, the DC-DC converter can't pull from it without setting off a low voltage on one of the taps.

I don't see confirmation that the 12V was load tested and confirmed good. This must be done.

I encourage you to refer to my last post. Grid charging/discharging is your next logical step to restore pack balance.

 

"My guess is that this technique sends a surge of electricity to the Main battery and kicks starts the charging process. How exactly I don't know, but it does work"

It's the above statement. It's wrong. That can't happen.

At any time prior to your "fix" did you rev the car to 3500rpm and hold until it started charging? Did you attempt multiple 12V resets followed by the prescribed revving (like half a dozen times)?

The symptoms you describe are a BCM that lost the SoC of the IMA battery due to the 12V failure complicated by the extended sitting period that subjected the IMA battery to excessive self-discharge. The return of IMA function was obtained by multiple ignition cycles and low level background charging that does not register on the gauge. It was simply a function of ignition cycles, background charging and miles driven. Your battery was going to come back eventually independent of your "fix."

The reason your "fix" worked was because the BCM was satisfied the battery voltage was sufficiently high to charge following your ignition cycle.

Far better to charge the car at 3500rpm sitting in the driveway rather than unnecessarily killing the ignition while driving.

 

Checking this thread out as, after surgery, my 2003 HCH sat idle for just over a week and when I wentbto drive it, the electric battery & charging/assist guages did not show anything. Was able to start car, drove a bit with no results. Was told to drive for half an hour or more and it would start to charge. No luck. Checked IMA fuses hoping for an ez fix. Nope. Question - revving at 3500rpms in park: how long before results show up? My 12v is fairly new, but I think it is getting drained by electric battery as that dummy light comes on in idle, usually not whike driving, althouh it did the first time I tried driving th car, but not during the hour drive. Have a local (non-dealer) hybrid guy on the ready but if the revving works I will be thrilled. Thanks!!

 

Have you disconnected your 12V for 30 seconds?

 

No, will have to get my son to do that for me later today. What does that do?

 

It resets the BCM. It's like pressing a reset button on the IMA system.

If you can read the codes before the reset, that would be a good idea.

I'm not sure about the HCH1, but a 12V reset on the HCH2 requires you to enter the security code for the radio or Navi system before it can be used. If this is the case with the HCH1, you may need the code. A dealer visit may be necessary. You can always do this later, but it can be a hassle.

Disconnect 12V for 30 seconds
Reconnect 12V
Start and idle car
In most cases, the car will begin charging at about 25% of the gauge.
If it does, let it charge until the SoC gauge shows full. You are good to go at this point; however, it is a good thing to do this multiple times to maximize the charge. Usually 3X is sufficient.

If it doesn't charge at idle, AND the IMA light is off, rev and hold 3500 rpm to force charge. If this doesn't work, repeat the reset process.

It can take multiple attempts to get this to work.

What likely happened is the extended sitting permitted one or more of the sticks to self-discharge below the acceptable threshold. The car monitors the sticks in pairs, so there are 10 different voltage readings. If the disparity between these voltages gets too great, the BCM will trigger a P1449 fault, and it can be difficult to get the car to charge the pack.

 

Thank you for your quick response. Was hoping to do this myself and save some $$, but think I am going to call my hybrid guy to do this. I'm not physically able - recovering from knee surgury and headed next to a hip replacement, so mobility an issue. Also my son works long hours, and as willing as he is to help, sounds like a long, involved process. Might be less painless for me to pay someone who can do the diagnostics as well as the charge. Thanks for your input. I will know more what the repair shop is talking about!

 

It's really very easy. You only need a 10mm wrench to remove the negative cable from the 12V battery and replace it. Getting into and out of the car to start it will be the most strenuous part of it. If a 12V reset is going to do it, the whole process should be less than 30 minutes.