[Aaron Cake]

Yesterday afteroon, I noticed a stunning lack of power when I tried to accellerate into traffic. Looking at the assist gauge verified that I was receiving no assist. Battery gauge was nearly full (as always), regen and auto stop functioned as normal. I continued driving slowly and carefully, observing what was happening. After several nice long regen brakes, the battery was totally topped off and regen ceased to be available (as expected). So I drove home, shut the car off, then turned it back on. Tore down the street a few times and had full assist as normal. Chalking it up to random weirdness, I went about my normal evening business of eating, working on my RX-7, and sleeping.

Fast forward to this morning. After starting the car and backing out of the driveway, I was again surprised to find no assist. As the car warmed up, idle stop began to function as normal, as did regen. I had no choice but to get through my morning service calls, and worry about the afterwards. During my morning routine, the check engine light came on. Still had regen and auto stop, just no assist.

Once back at the shop, I disconnected the 12V battery and tested it. 12.5V no-load, 11.5V load, so it seemed that the DC-DC was not doing any charging. After reconnecting the battery and going through the standard recal, I took the car for a spin. I had assist for about 5 seconds, just long enough to get out of the driveway. After that, nada.

At this point, I figured I would take the car to London Honda as it is still under warrenty and I don't have a code reader. Unfortunately, by disconnecting the battery I cleared the check engine light, and any stored codes. This light did not come back on during my trip to the dealer.

As it stands, London Honda has no idea what's wrong. Everything functions as it should, but no assist or DC-DC. 12V battery is nearly dead, so they have replaced it (I don't think they are aware of how that battery is charged, and the effects of cycling a standard starting battery). Still no code even though the car has been driven by the dealer for an hour or so. The car is still at London Honda, and I am assured that they will troubleshoot it.

This is a weird one...

 

[Yves M.]

Yes, weird, I wish you for the best. Maybe a new IMA battery

 

[Armin]

DC-DC

Aaron,

have you or the shop confirmed that the DC-DC is not working by measuring battery voltage with the battery installed and the car running (or in idle-stop)? 12.5V in no load are not that bad and without knowing what load you put on it, I don't know if the 11.5V is a problem.

Start the car, put the lights on and measure the 12V battery voltage. It should be 13.8V - 14.0V.

 

[Aaron Cake]

12.5V unloaded is fairly dead. Should be showing close to 14V if fully charged. At least, according to every other lead acid battery I have ever worked with.

It appears the DC-DC is working, but my 12V battery is weak. The 11.5V was measured with the headlights as a load, which is is a fairly light load. Regardless, it's well past dead. According to Honda, the battery has a bad cell, which would explain the 2V difference. I'll be putting in my own brand of 12V battery, designed for deep cycle standby applications.

It appears that the problem is the PCM, at least according to Honda. Assist almost always functions in 1st gear after the car was initially started. I observed this behaviour as well. But as soon as you leave first gear, asssist disappears. As of 8PM last night, they still did not have a CEL or code.

A new PCM is on it's way, and I currently have a Civic Hybrid as loaner. They say the module should arrive on Saturday. HOPEFULLY, the new code in the PCM is not radically different then the code in my original 2000 unit and lean-burn and driving characteristics remain the same. Unfortunately, the dead PCM has to go back to Honda, otherwise I would have loved to open it up and dump the ROMs.

This repair is being covered under warrenty.

 

[Armin]

12.5V unloaded is fairly dead. Should be showing close to 14V if fully charged. At least, according to every other lead acid battery I have ever worked with.

I don't want to start a fight, but I have to disagree with you, unless you are measuring with the charger connected and charging.

The battery is being charged to 13.8V. That is past the gassing point, so there is a current flowing to gas the battery lightly, this current causes a drop on the internal resistance. So as soon as this current stops (charger is disconnected), the terminal voltage drops. Now, depending on how long you wait, you'll still measure >13V for a while, if the battery was full. But for a partially charged battery (you mentioned DC-DC problems), 12.5V is certainly fine.

Granted, 11.5V with only the headlights as load is pretty low. How fast did it drop from there?

 

[Aaron Cake]

No argument...If the DC-DC is actually charging at exactly 13.8V, then of course the battery will never reach 14V. I don't have my service manual handy because Honda is using it to troubleshoot my car (anyone else find that funny?) so I can't look it up. However, I have never observed any significant gassing charging to 14V. At least nothing that can be considered past normal...

I didn't measure much past 11.5V as I just wanted to verify the current condition of the battery. 11.5V is past the official "dead" point the battery anyway.

At any rate, it's not about the battery.

Honda still has the car, and I have not heard from them. They said it could take up to a week to get the part, in which case the loaner Hybrid Civic they gave me needs a SERIOUS interior cleaning if I am to spend that much time in it...

I'm going to give them a call this morning to find out where things are at.

 

[jsanford]

Honda had to borrow your service manual?

No argument...If the DC-DC is actually charging at exactly 13.8V, then of course the battery will never reach 14V. I don't have my service manual handy because Honda is using it to troubleshoot my car (anyone else find that funny?)

Funny? Not exactly confidence-inspiring... :shock:

Keep us posted, this is an intriguing situation...

 

[Yves M.]

Actually, something similar happenned to me too a few years back. I let them have it because the tech used a CD in a laptop, and preferred a hard copy while working on the car. So I offered mine.

From "I don't have my service manual handy because Honda is using it to troubleshoot my car"

 

[Armin]

Re: Honda had to borrow your service manual?

No argument...If the DC-DC is actually charging at exactly 13.8V, then of course the battery will never reach 14V. I don't have my service manual handy because Honda is using it to troubleshoot my car (anyone else find that funny?)

Funny? Not exactly confidence-inspiring... :shock:

Keep us posted, this is an intriguing situation...

Actually, I think it's better than one of the bodyshops I looked at after my accident. They flat-out refused to even look at the service manuals after I offered. "We know what we are doing!"

Yeah, right, excuse me while I run...

 

[Aaron Cake]

I'm supposed to get the car back today. After driving a hybrid Civic for 4 days, I will be VERY happy to step back into the Insight. I hate to look a gift horse in the mouth, but I hate that Civic...The best I can get out of it seems to be 41 MPG.

Honda called me on Saturday saying that they wanted the car until Monday because they believe it is running lean. They say that have made this deduction based on the fact that the engine is "rough", but couldn't quantify what "rough" exactly means. Again, don't have my service manual handy, but I can't recall ANY mixture adjustment since the car is always in closed loop and it's the job of the computer to control the mixture. So I'm a little frightened about what they're trying to do.

Now, if they are complaining about the fact that my EGR valve is dirty, then I'd have to agree.

 

[Aaron Cake]

As a update, Honda still has the car. The original problem (no assist, no check engine light) reappeared a few hours after they replace the PCM. They are currently talking with the Honda tech line to try and get things solved....

 

[Insightful Trekker]

Please let us know what the problem ends up being. And _try_ to squeeze the specifics out of them :shock: I'm being a bit lazy here and could search for myself, but if yours is a simple open circuit failure then that's what I'm looking for to make my Assist Defeat modification.

Please help :!:

 

[Aaron Cake]

The good news is that I have the car back and everything is fixed. I picked it up yesterday morning, and things have been fine since then. I now have full assist back, and it looks like the car is working as it should.

The bad news is that the cause of the problem doesn't seem to make sense. Honda replaced the PCM, but the problem remained. They finally tracked it down to the LAF sensor. According to Honda, that is the second O2 sensor. Whey they just don't call it that is beyond me. Replacing that sensor fixed the lack of assist.

I had to cover the cost of the sensor, but the considerable labour, troubleshooting and PCM cost was covered by Honda under warrenty. I'm fairly happy with that.

 

[Yves M.]

Here are my $0.02

The Oxygen sensor is a generic term used since the carbs have been replaced (electronic systems uses the O2 but not carbs)

The LAF sensor is really a sub category of the O2 sensors. They are able to mesure a wider range of mixtures.

So all LAF are O2 but not all O2 are LAF



Good to see that it is resolved. Weird that ther was not an O2, sorry, a LAF code in the ODBII system
And also, you had the same as Ron. Weird concidence.


Addition: It is for Lean Air Fuel (LAF) sensor

 

[jsanford]

the obvious lay question:

What does LAF stand for?

Aaron, thanks for keeping us posted on all this. Did they offer any further explanation about the lack of error codes or how they discovered the source of the problem? Had they seen this before?

 

[Aaron Cake]

I gave them the suggestion that they should just refer to it as a "wideband O2 sensor" since "LAF" sensor is not mentioned in the service manual at all, while "O2 sensor" is. Or at least, "wideband lean AF sensor".

No, they didn't give any indication as to the cause of the lack of error codes. Also, the have not seen this problem before.

 

[Aaron Cake]

The saga continues...

On Monday morning, the check engine light illuminated as I headed out on the highway. Still had IMA, but no lean burn. There was no time to stop at the dealer, and their phone was busy when I called, so I left it alone until Tuesday. Well, the surprise on Tuesday was that halfway through the day, the light turned off. So I continued about my daily business, making a mental note to drop by Honda when I had some time and have them pull the codes.

I was still suspicious about the lack of lean burn, and as of yesterday I pretty much confirmed it. The weather was warm enough to eliminate coldness as the cause, yet I still could not maintain lean burn. Setting the MPG creeper at 75 MPG resulted in the engine running abnormally rough and the car quickly dropping speed. I could get the car into lean burn (or something that looks like it), but could not maintain lean burn. I am also fairly convinced that the car just "feels" wrong. The engine is rougher then it should be, and I have the feeling that it is lacking in power.

I guess the major problem is going to be how to communicate this to my dealer. From their point of view, the car is probably acting normally. They don't know the quirks and advanced driving techniques that we all do. And over the next few days, the weather will be well into the negative portion of the teens, so attempting a demonstration won't be possible sicne the cold is well past the point of lean-burn defeat. On Saturday, it's supposed to be exactly 0 degrees, so I am hoping I can take a Honda tech for a ride Sat. aftrernoon.

At this point, I'm starting to get frustrated. I'm not used to relying on someone else to solve my problems, and it's causing some serious stress. My greatest fear is to have this balloon into a negative situation, resulting in me hating the dealer, the car, and Honda in general. Not having lean burn is a HUGE PROBLEM for me, as I'm sure it would be for many on this forum. The issues is whether Honda will see it the same way...

On the PLUS side, I recently finished my custom battery tray, used to mount a small AGM motorcycle battery in the stock tray. I'll post some pictures once the paint dries...

 

[Yves M.]

The error code is probably still in the system. I was told that even if the light is off, the ecm will keep the error codes until a reset procedure.

If so, there is still hope. Maybe change your gas station. Bad gas. It sound like the O2 sensor is not all there.

 

[Aaron Cake]

I now have my CEL light back, and a service appointment on Monday.

I'm thinking as well that it is the O2 sensor. I've had more then one go bad two days after installation...

 

[Aaron Cake]

OK, part 3 (or 4? 5 maybe? Might be 17.375 by now...).

Got a call from the dealer yesterday regarding the no lean burn and CEL light. Apparently it's the secondary O2 sensor. For those keeping track, the cause of the original problem was the primary O2 (LAF sensor). And they replace the PCM due to a "LAF sensor software update".

While I do find it strange that both sensors decided to die at exactly the same time, and there was an O2 sensor software update, I have told the dealer to go ahead and replace the sensor. So I should have my car back on Thursday. Fingers crossed that everything will be fine...

Now, a little venting...

When I dropped the car off on Monday, I took Aaron (the tech) for a drive. I wanted to visually demonstrate the problems, and the differenes in the car. I went about pointing out all the little things that had changed since the last service (less assist, rougher around the lean burn point, nitpicks like the heater air mix motor no longer responds to the cold-hot control unless the heater is actually on, etc.). My major beef is that the tech contradicted me at every turn. Saying stuff like I'll never see lean burn at 40 MPH, that lean burn doesn't happen with the heater on, etc. Stuff that we ALL know is not true. I was in a good mood that day, so I didn't set him straight the way I ususally do. But I DID find it to be about equivelant to him sitting there and calling me an idiot. After all, I have been driving this car for 2.5 years, and have devoted a good amount of time to learning everything I can about it.

During the small conversation I had with the service guy yesterday, he read the current bill, which included a remark by the tech "test drove car, got 84 MPG on short trip, lean burn works". I'd like to trust him, but I know that there's a huge hill beside the dealership, and I'm almost willing to bet that this "short trip" was a coast from the top of the hill to the bottom. I have a hard time believing that he was able to achieve lean burn and 84 MPG, at the speed limit, with the CEL light on.

I intend to take these issues up with the dealer and get meanings clarified. While London Honda *has* fixed my problems, several things here don't add up...And I can's say that I am a satisfied customer based on the condescending attitude displayed by their tech.