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Discussion Starter #1
Hi!
The 6MT in my 2014 CR-Z needed to be overhauled (a bolt on part of the shifter assembly inside the gearbox broke, and the nut, lockwasher & spring fell into the spinning gears). After I got the car back, I noticed that regenerative braking wasn't working. The CHRG indicator very briefly jumps to 2-3 bars when I take my foot off the accelerator and quickly goes back to no bars. No CHRG bars appear at all when I hit the brakes. The IMA battery does charge when I drive, but even a small amount of stop-and-go traffic will drain the IMA battery down to 2-3 bars on the IMA Battery Charge Level Indicator. Usually I can keep that indicator at 6-7 bars with normal city traffic.

I took the car in to the dealer, described the problem to them, they ran a diagnostic and said the IMA battery charging was behaving normally. Which is true; the engine does charge the IMA battery. But I'm guessing the diagnostic doesn't cover charging from regenerative braking? My dealer didn't charge me for the diagnostic so I'm happy about that, but I would like to have the IMA available like it was in the past, especially when I need a bit more hustle to navigate traffic on a busy day.

I wanted to do some research before I take the car to another dealer. I'm thinking about buying the service manual to see if it has any useful information or hints, but I thought I would ask here first. Thanks!
 

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The only Factory Service manuals available for sale are for 2011-12 and the IMA system is one of the things that changed a bit in later years. Many on this forum have that manual available as a .PDF or you can buy the manual for that year here : 2011-2012 CR-Z Service Manual

I have tried since 2013 when I bought mine to get the factory service manual for my year and it is simply not available. You may be able to get the data you need from ALLDATA Online - Automotive Diagnostic & Repair Information or http://www.alldatadiy.com/ but that requires a subscription or a friend that has a subscription.
 

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Discussion Starter #3
I see... Then this online offer for a 2014 service manual is not legit?

I did find that PDF of the 2011-2012 CR-Z Service Manual and I downloaded it.
Thanks for your help!
 

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Have you checked the brake pedal switch? If this is faulty on not adjusted correctly, it won't tell the IMA ecu to activate the charging. Its not strictly speaking regenerative braking, in so much as you can get it to charge more without actually braking. If you slightly press the brake pedal, to operate the pedal switch, but not the brakes, the charging increases. By doing this, I can get my battery status to 100% by coasting down a steep hill in top gear for about a mile with the charging on max. The actual retardation due to the charging is barely noticeable even on a level road.
 

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In my opinion Not legit . Factory manuals are over $150. It might have correct information in it or it is a scam but it is not a factory manual. If there was a legitimate one I would have bought it as I did for my previous new cars.

I see... Then this online offer for a 2014 service manual is not legit?

I did find that PDF of the 2011-2012 CR-Z Service Manual and I downloaded it.
Thanks for your help!
 

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Discussion Starter #6
Have you checked the brake pedal switch? If this is faulty on not adjusted correctly, it won't tell the IMA ecu to activate the charging.
Looking at the 2011-2012 Service Manual, is that brake pedal switch the Idle Stop Switch? Does the MT version of the CR-Z have that switch?
 

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Not sure where it is, but it'll be the same one used to activate the brake lights. So have someone observe these whilst you move the pedal, which should be very little (<1/2"). (mine is an MT)
 

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Discussion Starter #8
The brake lights are activating because I can see them illuminating the wall when I back into a parking spot inside a parking structure.
I usually deliberately recharge the IMA battery by downshifting one or two gears, leaving the clutch engaged, and not using the brakes until I have to, when I'm approaching a stop at a traffic light or stop sign. I assume some other sensor(s) besides the brake light switch is used in that situation to trigger regenerative braking.
 

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I think the accelerator pedal position sensor is the main thing - pedal up, charging possible assuming car in gear and clutch up.
Brake pedal movement increases charging and as i said, on mine, a slight touch on the brake pedal increases the charging to 90-100% from 10-40% with no brake pedal movement.
I've found there is no need to change down as charging is not totally related to engine/IMA motor rpm.
It is strange that clearly some charging is happening or you'd have no IMA but its as if the IMA ecu thinks not much charging is needed. (like on mine, when the IMA battery is at 100%, no charging takes place)
I have a pdf on the IMA system but it's not very helpful as it assumes you have fault codes and doesn't actually cover any symptoms of a malfunction.
Does your auto engine stop work (stop/start)?
 

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Discussion Starter #10
Yes, the Auto Idle Stop is working properly.
I will get the usual one bar on the CHRG meter when I can drive at a constant speed so that's how the IMA battery is getting charged now.
The accelerator pedal sensor might be a good place to start. If I give the accelerator a tap, I will momentarily get a few bars on the CHRG meter when my foot comes off the pedal.
 

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If the accelerator position sensor (tps), wasn't working it would affect the petrol motor and the EML would come on so its probably okay.
How old is the 12v battery? Maybe the IMA is giving priority to charging it? (many IMA issues are due to a worn out 12v battery) Try connecting a charger to it overnight.

Looking at the pdf (albeit it is for the pre 2013 models), any IMA faults turn on in various combinations, the IMA, EML and battery symbols and there are about 50 fault codes AND the auto stop wouldn't work.

So the absence of any warning lights, a working auto stop and IMA assisting the performance are all signs of the IMA system being okay, leaving the 12v battery..?

If you change it, go for a drive out of town of a few miles to give the IMA time to adjust.
 

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After much digging through the manual, I have found that the brake pedal switch has 2 sets of contacts. This is a long shot, but I suspect that one set is for the brake lights and ABS, and the other is for the IMA. (one set is normally open - brake lights/ABS, and the other is normally closed)
So i would change the switch assuming its not expensive, before changing the 12v battery.
BUT first check fuses 7,8,9,10 in the under dash fuse box. Best to remove and refit,. (or swap for new ones if you can't test them with a continuity tester)
 

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If battery is more than 4 years old or still has the eye Replace it or at least get it load tested.
 

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Yes, the Auto Idle Stop is working properly.
At least on my 2014 CVT, the engine always turns on from Auto-Stop if the accelerator is pressed, even in neutral or if the brake pedal is also pressed. It even says that in the little info pamphlet in the glove box
After much digging through the manual, I have found that the brake pedal switch has 2 sets of contacts.
That is correct, they're clearly visible if you look up where the pedal attaches. I don't know what they do, but my guess is that one simply sends power to the brake lights, while the other tells the ECU if the brake pedal is being depressed. This would activate things such as auto-stop, max regen braking, as well as cancelling cruise control. I think these are worth checking, but my guess is that since auto-stop works, both the accelerator pedal and brake pedal sensors are working fine.

Another guess is that maybe the battery computer (can't remember its name. the IPU, I think?) 'thinks' the battery is hot due to a failing sensor. I read that, if the battery is getting hot, the car reduces IMA performance. Regen braking produces tons of heat since tons of energy is being dumped into the batteries very quickly, so it would make sense that if the battery is overheating then regen braking would be reduced.

Yet another guess is that your battery may simply be worn out. I don't know if the CHRG/ASST meter displays what the IMA system is trying to do, or what it is actually doing. if it is the latter, then it could be possible that the batteries are worn out and have excessive internal resistance. Since regen charges so fast, it could be that the battery surface voltage rises too high as the car tries to recharge it, so no matter how hard the IMA tries to recharge the battery, very little current would flow, thus the little display would not show any charging.

These are all just guesses based off what I know about the car and batteries in general.
 

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If IMA battery is hot it would be the IPU and maybe the IPU fan. No one here has had an IMA battery failure yet and most who have had the IPU fan fail have gotten an IMA light this member has no lights and no errors. it may simply be as I stated above a weak and or dying under hood battery. Most places will load test it for free.

If only regenerative charge is not working are there potentially failed sensors?
 

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If IMA battery is hot it would be the IPU and maybe the IPU fan. No one here has had an IMA battery failure yet and most who have had the IPU fan fail have gotten an IMA light this member has no lights and no errors. it may simply be as I stated above a weak and or dying under hood battery. Most places will load test it for free.

If only regenerative charge is not working are there potentially failed sensors?
I'm saying that a failing temp sensor could make the IPU THINK that the battery is hot, even if it isn't. However, I also imagine that if this were the case, the IPU fan would be spinning at full speed.
 

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After much digging through the manual, I have found that the brake pedal switch has 2 sets of contacts. This is a long shot, but I suspect that one set is for the brake lights and ABS, and the other is for the IMA. (one set is normally open - brake lights/ABS, and the other is normally closed)
So i would change the switch assuming its not expensive, before changing the 12v battery.
BUT first check fuses 7,8,9,10 in the under dash fuse box. Best to remove and refit,. (or swap for new ones if you can't test them with a continuity tester)
Yeah, that. ^^^ I was digging through the manual too, and came up with the same things to look at. I was also thinking there might be something that got plugged in wrong or a simple fuse/connection somewhere with the transmission rebuild--so, just check and recheck everything that was touched....
 

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Discussion Starter #18
The 12V battery was replaced in May of this year so it's fairly new.

Re: transmission rebuild
I was thinking (hoping?) that there is a driveshaft RPM sensor that was not reconnected properly when the transmission was reinstalled. My hypothesis: when I'm coasting in gear, the engine RPMs are too low to charge the IMA battery but if the driveshaft is spinning fast enough, then regen charging can happen.
But I don't know if there is such a sensor, and if does exist, where it would be located.

I'll check the brake pedal switches and the fuses.

Many thanks for all the suggestions! I really do appreciate all your help.
 

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And there would be a warning light!. Many have had the IMA warning light and it was the fan.
I'm saying that a failing temp sensor could make the IPU THINK that the battery is hot, even if it isn't. However, I also imagine that if this were the case, the IPU fan would be spinning at full speed.
 
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