# EU 7000is Generator Control Unit replacement



## Thomas Erhardt (Jul 4, 2021)

Hello. Posting as this may be useful to someone else.

I live in the Virgin Islands, a world away from any qualified Honda Inverter Generator shop. Since September of 2017 (Hurricane Maria) I have put just at 2,500 hours on an EU 7000is, most of it in the year following the storm but short duration outages since. The first symptom of a problem came when I had to replace a battery in too short an interval. All good for a short time but the second battery played out and I also noticed the I Monitor display was dead. 

Around here, going into an already active storm season, one cannot suffer a failing generator. Our power can be down for a month or better. 

The display that went out is on the Generator Control Unit so that was a good clue. Over $500 later I had a new GCU in hand. Next was to locate the shop manual online, which I did, a 256 page PDF. Every single detail of everything was in that manual. On battery info they mandated a particular battery, period, $239 vs the $100 AGM battery I had purchased. Ok, order, ocean freight and battery in hand. I don't know if this is a ruse to sell a particular battery but I trusted the Honda Manual. Now I'm into well over $700 in parts and the detail on replacement of the GCU scared me. If either I can't properly do the job or my $700 hasn't obtained the correct parts I have a $5,000 boat anchor.

In short, Remove the Handle, Remove the Front Cover, Remove the Inverter, Remove the Control Panel and Remove the GCU. Honda engineers have packed 10 pounds of components into a 6 pound bag. I copied the relevant PDF pages, got my 3/8 metric socket set out, took a deep breath and dove in. 

Proximity to the sea and near constant trade winds provides a saline atmosphere and I discovered some corrosion inside the front panel on galvanized parts and the type of surface corrosion one would expect on the cast aluminum inverter housing. That a a bit of dust that had migrated into the components was the only thing I encountered. The manual says you need Loctite 495 for a rectangular gasket between the cover and the control panel, you don't. The gasket was glued one side only and remained in place. 

The process going deeper into the machine was primarily a matter of removal of screws and bolts. There are a LOT of plug in wiring connections but each has a unique footprint so that's not too bad. Dismounting the plugs takes care and caution but close observation on how various plugs are locked in place and no damage done. Getting the old GCU out once exposed took some wiggling and prying, same getting the new unit in. I reversed the teardown, attached the new battery and now have GCU, iMonitor display with all correct values on the screen. I'm hoping for another 2,500 hours, at least.

Using an EU 7000is is an expensive alternative to municipal power, any way you look at it. The original cost at $5,000 equals $2 an hour for the machine st 2,500 hours. Running 4 hours in the morning and another 4 in the evening I could get two days out of a five gallon can or another $1 per hour in fuel, +/-. Now with another $700+ in the machine IF I can get another 2,500 hours my total per hour would decrease to $1.15 with the same $1 per hour in fuel and the cost of 200 hour oil changes. Bottom line, eight hours of power has cost me $24 per day or $720 per month, not including the new parts.


----------



## pipe (Jun 27, 2021)

Any pictures of the surgery and patient ?


----------



## Thomas Erhardt (Jul 4, 2021)

pipe said:


> Any pictures of the surgery and patient ?


Unfortunately not. I don't have a setup to allow the phone to be mounted and had enough to think about without a visual record. I think studying the shop manual first and then, "The process going deeper into the machine was primarily a matter of removal of screws and bolts" says it all. The Japanese engineering is precise but veery logical so no real surprises. Start breaking plug ends or sockets though and one would be in real trouble.


----------



## Thomas Erhardt (Jul 4, 2021)

Shop manual online: https://www.precisionusa.com/pdf/Ho...Shop Manual (Ser No EEJD-1000001-9999999).pdf
For reference in the long shop manual:
15-3 Handle Removal
5-5 Front Cover Removal
7-10 Inverter Removal
10-3 Control Panel/GCU Removal


----------



## Thomas Erhardt (Jul 4, 2021)

I purchased the GCU from a Honda Dealer in Virginia, likely less expensive sources are out there. I was going to be in Va. anyway so it was convenient to P/U and Priority Mail home. Lots of vendors refuse to use Priority Mail (Thanks folks for your service to zip 00824). FedEx or UPS are a magnitude of 10 times more to ship here, obviously no Ground, only 2nd Day Priority. USPS gets things here in 4 days! 

I shudder to think of the repair cost at a qualified shop, likely double my cost or more.....


----------



## pipe (Jun 27, 2021)

Good manual. It appears to be the old model of EU7000IS and not the new version EU7000ISNAG and EU7000ISNAN with Bluetooth and CO detection.

The iMonitor also has 5 settings, the 5th one being fuel level.


----------



## Thomas Erhardt (Jul 4, 2021)

Mine was shipped as new, Summer of 2017. Somewhere in my search I got the impression there had been too many GCU issues and the current P/N is an improved update. 

OK on the fuel level, CO detection addition for the lawyers and I swear, next thing to get Bluetooth will be Goats.


----------



## pipe (Jun 27, 2021)

Checking fuel level from tablet or phone remotely is indeed a goaty feature, love it, especially on rainy days


----------



## CrAshford (Dec 30, 2021)

Hey everyone! New to this forum as of today. Figured I’d toss up a picture of the GCU I had to remove today. Unit would not start and put out code E-00. The I-monitor would also say Batt=Battery and no spark. I went through many tests to figure out what the cause was and this is where it lead me. Picture is reference as to what to look for on the 7000s as per GCU! Just some info to help others if they come across this issue. If I find other issues and fixes I’ll be sure to update in the thread


----------



## drmerdp (Apr 10, 2018)

CrAshford said:


> View attachment 10735
> 
> Hey everyone! New to this forum as of today. Figured I’d toss up a picture of the GCU I had to remove today. Unit would not start and put out code E-00. The I-monitor would also say Batt=Battery and no spark. I went through many tests to figure out what the cause was and this is where it lead me. Picture is reference as to what to look for on the 7000s as per GCU! Just some info to help others if they come across this issue. If I find other issues and fixes I’ll be sure to update in the thread


Welcome to the forum. Its refreshing for a new member to open up with a proper repair with pictures to boot.


----------



## CrAshford (Dec 30, 2021)

drmerdp said:


> Welcome to the forum. I refreshing for a new member to open up with a proper repair with pictures to boot.


Thanks for having me. 🙏 I’m sure I’ll be using this site to trouble shoot things and give feedback at the same time. I’m a tech at a power sports shop just learning my way. 10 years green. It’s in the blood lol.


----------



## CrAshford (Dec 30, 2021)

Just an update to this thread. I changed out the GCU this morning at the shop and the fix worked. Unit is running like a charm  hope this helps people in the long run.


----------



## DanTheAutomator (7 mo ago)

CrAshford said:


> View attachment 10735
> 
> Hey everyone! New to this forum as of today. Figured I’d toss up a picture of the GCU I had to remove today. Unit would not start and put out code E-00. The I-monitor would also say Batt=Battery and no spark. I went through many tests to figure out what the cause was and this is where it lead me. Picture is reference as to what to look for on the 7000s as per GCU! Just some info to help others if they come across this issue. If I find other issues and fixes I’ll be sure to update in the thread


Do you happen to have a part number you're willing to share?


----------



## CrAshford (Dec 30, 2021)

I can get you the part number once I get to work. Not a problem.


----------



## DanTheAutomator (7 mo ago)

Thanks!


----------

