IMA assist not working properly... help? (video added)

[wizkid057]

Ok, so, today and yesterday I've had an issue with the IMA not working right...

I thought it might just be the heat (its been over 98 the past few days), but, it was cooler tonight and I had the same problem.

My IMA battery will be at a decent charge (5/8 to 6/8) and I'll be accelerating either from a stop or up a hill or whatever and I'll either get no assist at all, or it will top out at 2 maybe 3 bars of assist. The charging indicator still works as expected (charging during coast and 1 bar at constant speed). No warning or IMA light or anything.

I've seen it do this before when I've drained the IMA battery down to 2/8 bars in heavy traffic, but never when its at 3/8 or more bars.

It doesn't happen every time. Sometimes it works fine. But, it is happening often enough that it is actually noticeably impacting my mileage, and it never happened like this before this past Sunday.

Did the usual... checked fluids, fuses, etc. Only thing that was a little off was that the 12V starting battery seemed a little low on voltage with the engine off. 11.4v. I don't see that causing a problem with the HV IMA stuff though. If it were a 12V system problem most likely the 100V system's main contactor would never be able to engage at all.

Any suggestions before I contact the dealer service dept tomorrow afternoon? Only 3800 miles on the dang thing, so I shouldn't be having any problems at all yet...

CR-Z EX (US), Red, wo/Navi. 100% stock. (Would be 99% stock, but, I'm in an interim period with my CarPC project, so, the factory radio is back in temporarily.)

-wk

Edit:
Heres the video I posted on the second page:
2011 Honda CR-Z - IMA Problem? - YouTube

[MachVEvan]

...and it has happened before or after you removed the car pc?

I don't know how that could impact the IMA, but bad grounds can do funny things to the CAN Bus.

[wizkid057]

Originally Posted by MachVEvan

...and it has happened before or after you removed the car pc?

I don't know how that could impact the IMA, but bad grounds can do funny things to the CAN Bus.

Its after, but, I put the factory radio back in weeks ago.

Plus, the the CarPC setup didn't modify anything permanently. Just plugged into the factory harnesses so I don't see how that could effect anything. And I'd think it would have done something at the time I removed it, not weeks later.

[MachVEvan]

Exactly. So ruling out any modifications you have done, if I was working on the car, I would suspect the 12v battery, or a specific controller issue. Maybe has something to do with heat, but doubtful.

Sounds like a dealer only issue to me. Good luck.

[ocorreia]

Does it happen in all driving modes? I have the same problem in "econ mode", where I will get IMA assist only going up a steep hill or at the highway in high speeds. In "Sport mode" it will work just fine, getting full assistance right from when I start the car.

My IMA battery is charging and discharging properly as well.

But my car has always behaved like this, so I assume it's just the way it is

[holeydonut]

IMO, I don't get full assist unless the IMA meter is almost at full charge or I mash the gas pedal to the floor.

Are you saying there is no circumstance where you can get full assist with a partially depleted battery in any driving mode?



Driving to work today I was testing stuff out while going up a long 2% grade.

Basically if I kept my foot on the gas pedal with constant pressure then my mph was dropping about about 1mph per second. (let's call this Pedal Position X)

So I started to pulse the pedal where I would get full assist for 1 second then let off the pedal just enough so that it was back to Pedal Position X.

Halfway up the hill my battery charge was down to about 1/2. At this point, I couldn't get full assist to show up when I "pulsed" the pedal.

By the time I neared the top of the hill I still had 1/3 of the battery pack left and the only way to get any assist was to floor the gas pedal.

[SuiteMike]

Originally Posted by holeydonut

IMO, I don't get full assist unless the IMA meter is almost at full charge or I mash the gas pedal to the floor.

Are you saying there is no circumstance where you can get full assist with a partially depleted battery in any driving mode?



Driving to work today I was testing stuff out while going up a long 2% grade.

Basically if I kept my foot on the gas pedal with constant pressure then my mph was dropping about about 1mph per second. (let's call this Pedal Position X)

So I started to pulse the pedal where I would get full assist for 1 second then let off the pedal just enough so that it was back to Pedal Position X.

Halfway up the hill my battery charge was down to about 1/2. At this point, I couldn't get full assist to show up when I "pulsed" the pedal.

By the time I neared the top of the hill I still had 1/3 of the battery pack left and the only way to get any assist was to floor the gas pedal.

Honestly I couldn't agree anymore with this, it sounds like a normal thing to me when OP posted and what holey is saying is same thing tha happens to me, so personally I don't think anything is wrong with OP's CRZ just not used to the ima??? Or are you aying something else where we didn't catch on?

Sent from my SPH-D700 using Tapatalk

[wizkid057]

Thanks everyone for the replies.

Today I drove over 90 miles (mostly interstate) for work, and I didn't have the problem at all... so, I'm going to postpone calling the dealership until I can replicate the problem.

To answer some of the questions posed to me...
Yes, it was behaving the same in all modes. No more than 3 bars of assist even at wide-open-throttle with a nearly full IMA battery.

Today the car acted like this had never happen and I was able to get about 48 MPG for my 90+ mile trip.

@holeydonut + SuiteMike:
My trip to the interstate includes a steady incline that's reasonably steep and pretty long (nearly a mile). I've nearly depleted the IMA battery on it before when I was in a hurry. My Z seems to behave differently than how you describe. I might be crazy, but, my assist seems to work exactly the same all the way until the battery hits 2 out of 8 bars. Then it limits it to near nothing.

But at 3,4,5,6,7, or 8 out of 8 bars, I get full assist as needed without much effort. From a stop, up a hill, etc. Don't have to floor it or anything, just any increase in throttle gives assist for a bit. The behavior doesn't wavier for me at all until I drop below 3 bars.

*shrugs* Gonna let it be. I'll try to video it if it acts up, got my cam handy now because I wanted to show it to the dealership. Since today was much cooler it still may have been a heat issue... I really don't know.

-wk

[sneak1413]

Originally Posted by wizkid057

Thanks everyone for the replies.

Today I drove over 90 miles (mostly interstate) for work, and I didn't have the problem at all... so, I'm going to postpone calling the dealership until I can replicate the problem.

To answer some of the questions posed to me...
Yes, it was behaving the same in all modes. No more than 3 bars of assist even at wide-open-throttle with a nearly full IMA battery.

Today the car acted like this had never happen and I was able to get about 48 MPG for my 90+ mile trip.

@holeydonut + SuiteMike:
My trip to the interstate includes a steady incline that's reasonably steep and pretty long (nearly a mile). I've nearly depleted the IMA battery on it before when I was in a hurry. My Z seems to behave differently than how you describe. I might be crazy, but, my assist seems to work exactly the same all the way until the battery hits 2 out of 8 bars. Then it limits it to near nothing.

But at 3,4,5,6,7, or 8 out of 8 bars, I get full assist as needed without much effort. From a stop, up a hill, etc. Don't have to floor it or anything, just any increase in throttle gives assist for a bit. The behavior doesn't wavier for me at all until I drop below 3 bars.

*shrugs* Gonna let it be. I'll try to video it if it acts up, got my cam handy now because I wanted to show it to the dealership. Since today was much cooler it still may have been a heat issue... I really don't know.

-wk

It was 83 here today and my car started to do the exact same thing as you describe. It felt as it had no power to it at all in all 3 modes and i could not get more than 3 bars of assist no matter what gear, mode or how much throttle i gave it. I even downshifted at 45 mph to 3rd gear and held wide open and it felt like it had hardly any power. I stopped and turned the car off at the gas station grabbin a soda and when i got back into the car it behaved fine for the first mile or so then it started doing it again the same way. This has not been the hottest day here this summer but it is one of the hotter days and i have not seen anything like this behavior before on my car.

[wizkid057]

Originally Posted by sneak1413

It was 83 here today and my car started to do the exact same thing as you describe. It felt as it had no power to it at all in all 3 modes and i could not get more than 3 bars of assist no matter what gear, mode or how much throttle i gave it. I even downshifted at 45 mph to 3rd gear and held wide open and it felt like it had hardly any power. I stopped and turned the car off at the gas station grabbin a soda and when i got back into the car it behaved fine for the first mile or so then it started doing it again the same way. This has not been the hottest day here this summer but it is one of the hotter days and i have not seen anything like this behavior before on my car.

Sounds pretty much exactly like my issue. Would work fine for a bit, then act up... then maybe a little down the road work fine for a bit, act up, etc.

It didn't happen at all today, like I had posted, but the next time it does I'm going to contact the dealer and see what they say about it. It was 90F today on my way home.

As a side note, I'm surprised at how much power is lost without the IMA, considering it only provides an additional 13HP... feels like it loses way more when it's off.