P0685 ECM issue due to bad battery??? - Honda Element Owners Club Forum
      Honda Element Owners Club Forum
Go Back   Honda Element Owners Club Forum > Honda Element > Problems & Issues


ElementOwnersClub.com is the premier Honda Element Forum on the internet. Registered Users do not see the above ads.
Thread Tools Display Modes
Old 01-13-2010, 10:36 AM   #1
EOC Rank: Hydrogen
Join Date: Mar 2005
Posts: 4
P0685 ECM issue due to bad battery???

Hi guys. I need some help!

Our 2004 element 4wd auto transmission with no modifications is behaving badly. At low RPM the accessories sometimes momentarily turn off - fan/HVAC stops, radio silences, etc. At the same time, a bunch of indicators flash on the instrument cluster (abs, etc) then power returns. Sometimes it's almost unnoticeable because it happens so quickly, other times the car has died. The more severe instances have resulted in the check engine light coming on. The light generally goes out and the car seems to start and run normally until these same symptoms reappear with the exception of the airbag light which stays on.

I searched through the archives and only found one other reference to P0685 but some of these symptoms seem fairly common...

I took it to the dealership. They recommended an ecm relay and ecm replacement. We replaced the relay but not the ecm according to their procedures.

The problem came back within a day so I returned to the dealer this morning. The computer showed DTC P0685 (losing power voltage in the ecm). They indicate that the optima battery is providing only 17 CCAs but the starter and charging systems are fine. I'm off to replace the battery even though she seems to start like a champ... dealership wants to address the issue ("if it recurs") with a known good battery.

Is it plausible the battery is causing the problem with the ecm? Any thoughts y'all have are welcome

[beetlegeuse] is offline   Reply With Quote Quick reply to this message
Sponsored Links
Old 01-13-2010, 10:55 AM   #2
2008 4WD EX-P 6MT
Galaxy Gray Metallic (GG)
MikeQBF's Avatar
Join Date: Sep 2003
Location: Downstate Illinois
Posts: 6,407
Yes, intermittent battery or intermittent connection to it would result in your symptoms. That you have an Optima raises the likelihood of battery going south in this way, significantly.
MikeQBF is offline   Reply With Quote Quick reply to this message
Old 01-14-2010, 08:39 AM   #3
EOC Rank: Hydrogen
Join Date: Mar 2005
Posts: 4
Thanks, Mike. Got a new battery in there...the optima lasted 2.5 years.

I haven't seen the above described symptoms reappear, but we probably need to drive a bit more to be sure. It seems to operate more smoothly at idle speed whether underway or parked with the new battery, so that's a great sign.

Thanks again! I'll post up if the saga continues.
[beetlegeuse] is offline   Reply With Quote Quick reply to this message
Old 09-03-2013, 10:36 PM   #4
EOC Rank: Hydrogen
Join Date: Feb 2008
Posts: 1
Same Problem

I'm having the same problem as the original post. Wondering if there is an update, or any suggestions I should try. I already blew $50 on the diagnostics for them to just tell me to go to the dealer. They said it could be fixed if the ECM/PCM is updated, but it may need to be replaced. I have no idea how much this would cost. I replaced the battery probably 2.5 years ago and have about 140,000 miles on the car total. I lose radio power when I have my AC running occasionally, but today I had the RPMs go up and a malfunction light come on. Any suggestions would be appreciated.
TOMATO is offline   Reply With Quote Quick reply to this message
Sponsored Links

  Honda Element Owners Club Forum > Honda Element > Problems & Issues

Quick Reply

Register Now

In order to be able to post messages on the Honda Element Owners Club Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Model Year
What year is your E?
What model is your E?
What color is your E?
Can you spell?
What letter in the alphabet is the fifth character of the word "Honda Element"
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Battery issue 2008 k8cagney Problems & Issues 10 04-22-2008 09:08 PM
Battery or alternator… what’s going bad??? wheels041605 Mobile Electronics 18 03-27-2007 04:14 PM
Bad Battery? ZosoRules1 Mobile Electronics 1 01-28-2005 02:45 PM

All times are GMT -5. The time now is 05:47 PM.

Views and opinions expressed on this forum are not necessarily those held by Autoforums, Inc. or forum management.
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.