I am happy with my 2010 Fit Sport, but happier when I can get it started
When I bought it, it had no issue starting. However after driving it for a month, the green key light on the dashboard would come on, signifying that the immobilizer has kicked in.
I've used several methods to temporarily bypass the immobilizer (click unlock on the remote 5 times, etc), until finally I could not use any of the bypass tricks.

I've tried different ECMs, an immobilizer units. I've registered them using X-Tools D7. I was able to successfully add 3 additional keyless remotes. All three would initially work for a while, but then the green light would come back.

I've had a Honda tech using their diagonstic tool try as well, and the software said it could not establish communication. They said the immobilizer would be recognized once, but fail thereafter. This was done with a new OEM immobilizer module.

The 12v battery is freshly charged, and I tried 3 remotes on the same physical cut key. All three would work, but they would suddenly stop working a few hours or days later.

Now I'm down to a few ideas:

1. Sterilize the immobilizer.
2. Install a remote start kit - will this work, given the condition it's in now?
3. Bring the Honda techs back and try a different junkyard ECM.
4. Flash the ECM so it does not need the immobilizer.
5. Install an aftermarket ECM like Honda Data

I don't want to put more money than I need too in this car, but if I can't get it running, I'm going to sell it off to a wholesaler. It's a shame because it's a manual with 105k miles.

Not sure if this had anything to do with it, but the battery had a parasitic drain, and after replacing the original ECM, the drain was resolved.

 

Immobilizer issues are a touchy subject. Not many people are willing to give out information on how to bypass this security feature as it can cause many cars to be stolen.

Your issue is complicated now that you have replaced or swapped several different components, without actually knowing the real cause of the issue. To me it sounds like something is not communicating the key code to units that are requesting that information. Its either a bad component that isn't reading it or sending it properly. If you really want to figure this out, read the Immobilizer System section of the factory service manual that will give you troubleshooting steps and in depth knowledge of the system.

My question is what made you think the ECM was the culprit for parasitic drain?

The Honda Fit has two main components that drain the battery when sitting. The security feature on the factory radio and the factory alarm. Along with the 151R battery being small and weak.. it cannot sit for long periods of time without a battery tender.. otherwise it will discharge on its own being grounded in the car.

 

Good point about the 151R battery. I would charge it up fully, let it sit for 8 hours, then check using a battery meter. It shows 100%.
I manage to get the car running once, drive around for 30 min. Leave it sit overnight, try to start it again multiple times, and it's at 72%. I've also tried a new Honda battery, and it didn't resolve my starting issues.

I've looked at the FSM, and to be honest with you, I could only follow half of the content. It's made for a tech or enthusiast who understands the acronymns.

Given the number of Hyundai/Kia thefts, I can see why this is a touchy subject. I'm not asking people to say how to bypass the anti-theft measures Honda put into place, but rather what they've done to resolve their issue. Taking the car to a stealership here in my city is an invitation to get robbed. I just want to get the car running reliability. That's not much to ask I hope.

A number of other members on the forum have said they've been left stranded, sometimes in the middle of the night. I would never allow my wife to drive it, for fear that she'd be stranded somewhere. I also have an Acura TL and Accord, and they're both fine cars. I think I just have a lemon.

 

My car is a 2013 Fit Sport with 70k miles on it and I can tell you that it does the same thing as yours. I keep a battery tender on it and it monitors the % and it can sit at 100% all day with the tender. As soon as I take it for a drive and put the battery tender back on it shows its 80%. So I think your car is within an acceptable range. As long as the car can start it should be fine.

The FSM is indeed made for technicians that is its purpose. But you if you don't want to be "robbed" at the dealer you are going to have to learn to troubleshoot this or find a trustworthy tech that will repair this at a reasonable cost to you. Immobilizer issues are often complicated and difficult to diagnose especially if you don't have the proper scan tools to do.

I would not trust a car that has this type issue as well and leaving your family stranded is a completely understandable. I had a 2002 Jeep Cherokee that was working fine, until I decided to wash the engine bay and after that it had immobilizer issues.. where the car started up for a few seconds then cut off due to an electronic issue where one of the immobilizer components could not verify the key code. The fix for that was to remove the device around the ignition switch that read the key RFID code and to send the ECU out to have it re-flashed with immobilizer disabled. (That is not a proper fix) as the car can be stolen now. Many Jeep owners experienced the same issue and that was their solution.

Did this issue ever occur before you replaced the original ECM? That would be a starting place to start trying to troubleshoot.

Check page 22-323 of the FSM it lists the symptoms troubleshooting for the indication light pattern.

 

I just did a quick check on the internet and found this video. The car mentioned in this video I believe is a Honda Pilot, but the info is interesting and to the point of the issue you're experiencing. Check it out:

 

Great video! Hopefully for the OP its something simple like that fuse.

 

That's very reassuring, good to know that this behavior is normal

I'll try to make sense of it again. If I get stuck, perhaps someone on the board might be able to point me in the right direction.

I had car since spring 2022. I didn't drive it much, as it had a salvage title. I eventually had the body work done (rear 1/4 panel), and it passed the state inspection. I started driving it regularly in Jan 2023 and a few weeks later, the blinking green key came on intermittantly. I was using the many temporary by-passes (clicking the remote several times), until one day, all the bypasses stopped working. Three ECMs three immobolizers, and three months later, I'm in this position. What is bizzare is that newly installed ECMs or immobilizers would work for a few days (after programming with a non-Honda scan tool), then it would just stop.

At best, it's a physical problem (thanks 57ChevyDan) like a fuse or a loose wire, and at worst, it's a software problem (aka Apple IOS that locks up after 10 failed attempts).
I would think it's a wiring problem, but the green light would go off on one try, and 10 seconds later it would blink on the second try. All without moving any wires, starting the car, touching anything, or any other movement other than breathing.

 

I called American Honda Customer relations and there is no recall, brake code, or other assistance available. I'd have to have it towed to the dealer.

 

Updated: I followed the FSM instructions which indicated a gauge cluster malfunction. Replaced the cluster and still have starting problems. Two Honda dealer techs visited me three times, spent over 5 hours total for diagnosis and still were not able to find the issue.

 

The key will work some of the times on mine. Did you ever figure out the issue?

 

I took it to a shop and they diagnosed the problem as wiring issues, not component malfunctions. I couldn't understand why because there was no physical damage (accident, water corrosion,etc) under the dash.

 

Did your car have any aftermarket equipment added on back when the fault was occurring? (like a dash cam, stereo, etc.?)

 

it was bone stock

After trying to deal with this over 6 months and spending over 2k in repairs, I sold it as soon as I got it fixed. Also having bought a 2001 Acura TL for $2k, with power and smooth ride convinced me to sell.