[ron]

This weekend my Check Engine light came on and at the same time I lost all power from the electric motor. No action in the ASST indicator, (although it seems to be charging ok), and a noticable drop in power.

I'm at 73800 kms (45800 miles).

So I took the car in to be checked this morning and was told I have a bad O2 sensor and it will cost $230 + labor. I think some people have been able to coax their service manager to do it under warranty, but I'm told it's a 'wearable part' and hence is not covered by the extended warranty, which I am now starting to regret buying.

To me, if a wearable part costs more than brake pads or a filter, shouldn't I know about it in advance? Note to car buyers: Don't go for the extended warranty. At least read the fine print first.

-Ron

 

[Yves M.]

I had that on the first year. It was something like, the system detecting that the O2 sensor is bad, the system goes into a default mode (a very stupid mode) of removing the Assist mode of the IMA. So then I had 100% SOC until they replaced he O2 sensor and had to rev the engine in order to change gears.

After the replacement, I noticed that my MPG was lower.

I wrote "stupid mode" because, I see no relation to the lost of IMA assit. It would have been beneficial to keep the IMA since the gas engine has a problem.

Good luck with a warranty replacement. Isn't the O2 sensor part of the emission system and therefore into a longer warranty than the base warranty?

 

[Willie Williford]

Don't know about Canadian "smog laws" but in Calif. I think the 02 sensors are part of the emmissions and are covered a lot longer than the basic engine warranty. Check with DMV, they should have the rules. That is probably the right price on the 02 sensor, labor should not be over 1 hour to replace and get a "reading". When posting KM please post in miles for those of us who are a little senile, please.

 

[ron]

Yves, did you have your O2 sensor replaced under warranty? I also think that it should be covered because it's part of the emission control system, but I have my doubts. The Canadian extended warranty excludes it if I remember correctly - I'm checking this as soon as I get home today.

I agree with what you said about 'stupid mode' - I thought the same thing. Why would they tie these two systems together? Oh well..

Will let you know how it works out.

Thanks,
Ron

 

[Insightful Trekker]

If I'm reading correctly here the "stupid" mode happens _because_ the O2 sensor is a primary input sensor for injector control. Once the system "knows" that this sensor's data is untrustworthy then all it can do is go stupid.

Actually its operating on a "best guess" mode to keep the engine running and allow driving to get to a repair shop. Honda used to call this Back-up mode and AFAI remember limp-home mode was the term used by one of the big 3 Detroit manufacturers.

Several other primary input sensors will have the same effect.

More specifically you asked,

Why is the IMA assist limited with an ICE fault?

Well its a complex question with several probable answers.

Without the ability to accurately "know" what's headed toward the CAT (catalytic converter or simply catalyst), the CAT can easily be superheated and would fuse into a solid plug of clay in the exhaust system. The most direct way to accomplish this "blindfolded" is limit the ICE's ability to _produce_ power thus keeping the resulting exhaust in a known safe range for the CAT's happiness. Some of these "parameters" are regulated by the OBDII government specifications although I don't know how it applies specifically in this situation.

By turning off the IMA system you prevent any forced charging of the IMA pack and also keep the ICE's load in a known limited safe range. To allow IMA operations you would have to further reduce the ICE's restricted power "plan" to allow for any potential IMA charging load. At best making the car's performance similar to what you are now experiencing with IMA assist and worse when a forced charge need occur. Yes, the best system would be to only turn the IMA system 1/2 off, allow assist but restrict charging. Seems like little benefit in that the IMA batteries will soon be empty with no opportunity to charge.

Then there's the "cheap" shots like; They want the car to drive badly with any fault so you'll have to pay to fix it. But I really believe its more complex than that especially in this specific situation of CAT "protection". There _are_ several OBDII design requirements in regard to CAT "protection" when a primary input sensor fails.

p.s.. I hope your not *just* a dog lover since all this reply is about CAT happiness. <VBG>

HTH! and THANKS :!: for the Forums :!:

 

[Yves M.]

My replacement was under warranty but it was within the 3 year/60k km section.
I checked my warranty booklet,
some things are 5 years/100k km
the catalytic converter and the hybrid system is 8 years and 130k km.

But two things I noted:

the O2 sensor is NOT in the emission system list
the DC/DC converter is NOT in the hybrid system list

But both should be covered to me. They always figure not to give warranty on things that break. Best luck.

For John,
It is the "cheap shot" because the IMA charge and regen worked (until it was full). Only assist did not. They wanted the car not to drive properly for repair co$t.

 

[ron]

Thanks all, for your comments. I had my mileage wrong but fixed the top post. I'll have the new O2 sensor put in on Monday at my expense.

Oh well. Still love this car, even with the occasional hit to the wallet.

Ron

 

[Guillermo]

Make sure the dealer phones the Canadian Honda Tech line.
My dealer did and Honda tech decided to replace my ECU for free under the ECU recall (again) instead of the O2 sensor to see if that fixes the problem.
My ECU was replaced by another dealear last year but they decided to try again. weird...

I'll keep you posted if this solves my check engine light caused by a O2 fault code.

 

[ron]

Wow, so they replaced the ECU a second time just to see if that was causing the O2 sensor code? Seems like there's more to that story, ie: an ECU problem with the ones they used for the recall.

Thanks,
Ron

 

[Guillermo]

No luck,
even with new ECU the check engine light came on again after 3 drive cycles. I'm bringing in again and the next step is to replace the O2 sensor.
Hopefully this solves the problem.
I've been ignoring this problem for 10 months because it doesn't seem to affect the car in any way. But i'm going to fix it once and for all.
I'll keep you posted in the comming weeks.
G

 

[ron]

Thanks G,

On my first time putting gas in the car after I noticed my problem, it caused my Assist to start working again! My check engine light remained on, but as I drove away from the gas station I had my assist working fine. However, on my next trip the assist stopped working again. It flip flopped a couple times like this (working, then not working) but it's now been operating normally for several days.

I'm hoping it's just 'bad gas' or something that caused the bad-O2-senser code. I'll know more Thursday when I bring it in.

Ron

 

[ron]

Just to put some closure on this... they claimed the sensor was failing intermittently, which I can understand. Even if I could go a week or a month without replacing it, I'm sure it would just be a matter of time before it bacame permanently dead.

So now I have a new O2 sensor! woo hoo! My emission system is now happy. My bank account however... :?

Ron