High Mileage Clarity PHEV - Reliability, Maintenance, Cost

Discussion in 'Clarity' started by Kundan, Jul 10, 2019.

  1. craze1cars

    craze1cars Well-Known Member

    And just to be clear, B18 controls a couple relays. And for those who don’t understand relays (electrically controlled switches for high current circuits that are held in a closed position with low current provided from a different circuit), all you need to know is that you pull that fuse you will lose ALL of those functions of the car on the list including the entire climate control system and DRLs, which is not practical or smart for purposes of the question presented. Poster was hoping to isolate and cut power to the resistance heater only. B18 does not do this.

    If you wanted to isolate and disconnect the resistance heater, ignore all fuses and just unplug the thing from the car. And to be perfectly clear, I don’t recommend messing with it and have no reason to believe it is running unnecessarily in the background, as seems to have been implied by one person here. Look elsewhere for solution to perceived reduced range problem...
    Last edited: Jul 16, 2019
  2. K8QM

    K8QM Active Member

    We have 34,788 miles on our 2018 after 17 months of ownership. Our dealer offers "free oil changes for life" so I have had the changes done on the MM schedule. I do let them rotate the tires for $21 but decline the balancing. Once the factory tires are replaced I'll take it to the tire shop for rotations, as they include that in their price.

    Our only issues have been the Multiple Warning Lights and the battery cooling overtemp problems which have not occurred since the firmware updates were installed last year.

    In North Carolina, the worst Winter EV range is in the low 40s and the Summer EV range has been in the mid 50's this year. It was actually up into the low 60's last year but I think a combination of a lot of highway driving and higher than normal temps has pushed it down a bit this summer.

    I did buy the HondaCare F52 (5 year, 120,000, $100 deductible) warranty from Hyannis last week since some issues with the tech in the Clarity would be outrageously expensive to fix out of warranty.

    Even with the Clarity's occasional funkiness I would love to be able to buy a CRV like Clarity (maybe drop the EV range to shed some weight).

    The Gadgeteer likes this.
  3. ClarityBill

    ClarityBill Active Member

    Heat will reduce the relative humidity of air. Many dehumidifier systems include a reheat function to eliminate the 'stuffiness' of the air.

    Since the Clarity is operating on a temperature control, if it has a dehumidify mode, it would need a reheat system to maintain cabin temperature.
  4. craze1cars

    craze1cars Well-Known Member

    Understood. Raising air temp lowers relative humidity. But cold surfaces physically remove the water and dump it on the pavement. I am unaware of any humidistat in any car, so it’s a thermostat based system that has no earthly idea if it’s cooling dry AZ air or humid FL air. I find it highly unlikely that any car has a summertime dehumidification mode. They just run the AC compressor to pull water and lower temp at same time, sometimes with recirculation mode, and meter temp to prevent overcooling with reduced fan speed and the air mixing flap in the ducts. The only time the AC and heat would be running at the same time in some cars is in defrost mode in warmer winter temps. Many cars have done this for 50 years. Compressor may run then to cool the coils in an effort to physically remove moisture from cabin and dump it on the ground instead of blowing it onto the glass to help keep windows clear.

    I guess my blunt point is if Honda has programmed the cabin heater to come on in the dead of summer and waste electricity for any reason on the Clarity, that’s is some truly incompetent engineering on their part.

    Whoever thinks this heater coil is the reason for reduced electric range mid summer is looking in the wrong place unless they have their climate control set to 95 degrees all the time and the heater actually is coming on periodically.

    If electric range is being reduced this summer when compared to last experience, there is a different reason that has nothing to do with the resistance heater.
    Last edited: Jul 16, 2019
  5. fotomoto

    fotomoto Active Member

    I also have a C-Max Energi which has a climate usage display covering a range of 0-5 kwh usage and I can observe spikes to 5kwh by simply moving the interior temperature a degree or two that activates the heater loop. When conditions are right such as when ambient and HVAC set temps are close, (unintended) heater use can happen. Never an issue here in the summer..... :eek: but in our cooler months when mornings are in, for example say, the lower 60's, moving the interior temp from 70f up to 72f can activate the Energi's heater loop. When I see this, I adjust the climate control down a degree or two and the spike goes back to normal levels. Just turning the HVAC on or off typically causing the FORD GOM to jump anywhere from 2-5 miles depending on time of year. This doesn't sound like much till one considers this is on a 19 mile (5.5kwh) battery so that's a fairly significant percentage.

    Since I bought the Clarity in late spring, I don't have any experience with it in cooler temps yet but so far I have notice the GOM is fairly resistant to changes in HVAC settings but as we know a/c use pales in comparison to electric heater use.
  6. ClarityBill

    ClarityBill Active Member

    I was steered wrong by something I had read in a thread on this forum:

    "The humidity/in-car temperature sensor has a humidity sensor and an in-car temperature sensor. The climate control unit receives humidity information from the sensor to help control the electric A/C compressor operation. When it is humid, the climate control unit operates the electric A/C compressor to prevent the windshield from being fogged. When the humidity is low enough, the climate control unit reduces the operating time for the electric A/C compressor. A flexible hose connects the sensor case to an aspirator on the HVAC unit to detect the accuracy of temperature and humidity."

    I guess you can't believe everything you read on the internet, but this quote made me believe the Clarity had a summertime dehumidification mode.......
  7. craze1cars

    craze1cars Well-Known Member

    Well don't be too hard on yourself. In fact let me just eat a big old serving of crow right here and now. Honda sells Humidity sensors as parts for several of their cars...I can provide several part numbers. And here's a link for CLARITY's Humidity sensor. It DOES exist!!: https://www.hondapartsnow.com/genuine/honda~sensor~humidity~80590-trt-a41.html

    I had no freaking idea. ClarityBill, that quote you found may well be 100% accurate and I am not going to condemn it in any way. Shame on me for assuming I know things just cuz I'm an old mechanic. I was wrong and I wrote things without any research. I hate it when others feed internet inaccuracies with assumptions and and now I did it myself...live and learn.

    However if that quote you found IS accurate, I'd like to point out that nowhere in that quote does it mention that Clarity would turn on the electric resistance heat to add to the dehumidifying process. As I would expect it only references the AC Compressor...because that's the only way to physically remove water from cabin air. Heat alone doesn't.

    So I will stand by my statement that the electric resistance heater has no reason to be running in the summer when the system is not calling for any cabin heat.

    My sincere apologies to all for making assumptions instead of seeking facts and derailing this thread. Carry on!!
    Last edited: Jul 16, 2019
  8. 2002

    2002 Well-Known Member

    Ugh, sorry for another long post but lots of topics being covered in this thread, as well as I think a breakthrough in isolating my odd noises. Sorry nothing solving EV range issues here, so feel free to skip this if that is all you are interested in, my post is all about climate control.

    My experience with climate control on my previous car (Prius) as well as rentals is that climate control systems don't allow you to directly control whether warm coolant flows into the cabin, or the amount of coolant flow, like you can on a manually controlled car. Even in manual mode a climate control system only allows you to turn the AC compressor on or off and control the fan speed and which vents are used, but not coolant flow. At least in the cars that I have been in. In climate control systems you only have indirect control of coolant flow by setting to a particular temperature. The system then decides based on the set temperature if it needs to run AC or bring in warm coolant to maintain that temperature. Or use outside air if the outdoor air temperature is in the right "direction". Or if the set temperature is close to the current cabin temperature, and the outdoor temperature is in the right direction, then simply do nothing and allow the cabin temperature to change on its own, even though that might take a little longer.

    I assume that smarter systems, especially hybrids where the engine is not always running, if the outdoor air is in the right direction (i.e. warmer than cabin air) they will be much more likely to use outdoor air when warmer air is needed, or else the "do nothing" method if the set point is close to cabin temperature.

    Okay so now we have Clarity where the only way to bring in warm coolant if the engine isn't running is to use the resistance heater. One theory that has been floated is that it is doing this to maintain humidity. I think this is unlikely, or at least it would be mighty dumb to do this all the time and not just when the driver pushes the windshield defrost button.

    The other theory (the one I was considering) is that Clarity is not being as smart as it could be when alternating back and forth between AC and warming to maintain the set temperature. Maybe while it attempts to maintain the set temperature it is sometimes using the resistance heater when it could be using outside air, or when it could also simply "chill" (pardon the pun) and allow the cabin temperature to warm back up on its own naturally from outside heating. But hey we have seen dumber things so the theory of there being a bug in the software causing the resistance heater to run when it doesn't need to is not that way out there, even if it is unlikely.

    I actually wondered if the odd noises that I hear from the passenger footwell could be due to this, which is why I also was interested if it was possible to easily (and safely) disable the resistance heater at least temporarily for testing. But once I saw on the chart that it does not have its own fuse then that obviously isn't an option. As for unplugging the heater, that might throw a code, and anyway I'm with craze1cars I don't recommend experimenting with anything on the HV side of things.

    And I have late breaking development in my noise investigation, I removed the plastic panel that is underneath and behind the glove box, the panel pops out pretty easily. I can now see the two different rotating parts that are making the noises that I am hearing. I can turn the temperature dial and at will make these parts rotate and make their odd little noises. I am not quite there yet identifying them yet or even taking photos but my initial guess is that one of them rotates to change which set of coils the air is flowing over, or if not that some other change in airflow direction. This one, which is a relatively large blue plastic wheel or disk of some type, I can cause to rotate back and forth at will by turning the temperature back and forth once I find the set point where it occurs.

    The one that makes the odd tick/scratch sound that I hear is a smaller, white plastic rotating wheel/disk located closer to the firewall, which I am guessing controls airflow from outside in order to bring warm air in rather than having to run the resistance heater. If I move the temp setting a few notches, this "wheel" ticks and then rotates a few degrees (the scratching sound is the motor) then stops rotating, then about a second later it ticks and rotates again a few degrees, and it keeps doing this several times, starting and stopping (and a tickin' and a scratchin') until it reaches where it wants to be. If I then turn the temperature knob a few notches in the other direction, the wheel starts its approximately once per second movement in the other direction. I am guessing that it does it in increments so that it can measure the temperature change after each short movement and then increment more degrees as needed until it reaches the temperature it wants. Total guess on my part but it looks perfectly normal what it is doing, but maybe mine is noisier than others if I am the only one who hears it. If there was a cacophony of other odd noises I probably would not have isolated this one, but other than the brake pedal solenoid tick I really don't hear any other odd noises during driving which is why this one stood out, and also because I didn't start hearing it until a couple of weeks into ownership, which I now realize was right around the time that the weather started getting warmer.
    sniwallof likes this.
  9. sniwallof

    sniwallof Active Member

    Forget pictures, that description calls for a YouTube video, with commentary! (from the guy who didn't take pics for the pillar cover removal)

    I often skip over long posts, but I have to say, reading your description of the moving parts was actually kind of fun.
    2002 likes this.
  10. Danks

    Danks Active Member

    Sounds like the noise I hear in my Clarity. Thanks for digging into this.
    2002 likes this.
  11. 2002

    2002 Well-Known Member

    Even before I realized that it was related to climate control I noticed that I tended to hear the noise earlier in a drive, then it would mostly go away, which makes sense now that I realize it likely occurs when the system is trying to get the cabin to the set temperature, that's when it does a lot of the repeated tick/scratching (guess I'll keep calling it that). Afterwards the noise is occasionally heard but for much briefer periods, probably as it makes adjustments to keep the set temperature. I'm generally attuned to climate control noises in cars but those are usually more obvious like vent doors opening and closing and other squeak type sounds, but this incremental business creating repeated ticks had me really thrown for a loop until I saw what it was. Of course I'm still just theorizing exactly what is happening but I feel like it's probably along the lines of what I think it is or something similar.
    Johnhaydev likes this.
  12. Hoon

    Hoon Member

    I was searching if there's a way to disable the heater coil using power during summer months. This is my day 2 with Clarity. I had the temperature set to 78F with AC ON last night as it was 90F during the day. My garage was still warm (around 80F) from last night, and this morning outside temperature was around 60F. While driving to work, I noticed the heater is pumping out hot air so I had to manually lower the temperature, then the AC would kick in. I turned off the fan completely. I will be using remote climate, so I need that AC to be ON.

    Any suggestions? Looks like there's no way around this. I really don't want the heater to be involved unless it's really cold like 40F, but it looks like it's an old carry-over design from a conventional ICE car where heat is free.
  13. 2002

    2002 Well-Known Member

    I highly doubt that the heater coil activates during summer, it seems extremely unlikely that it does that. What the AC system does do as stated in the technical manual is "regulates temperature air outlet by mixing cold and warm air in an appropriate ratio". I think this means mixing outside (warm) air with inside (cold) air. This is still not good and I wish there was a way to disable this. It is also very noisy at least in my car as it constantly adjusts the door that regulates this. Especially noisy at the moment as I still have the panel off under the glove box, so I can really hear it and that door motor is constantly running as it moves the door back and forth, it will probably wear itself out at some point, and it's noisy, and it's bringing in warm air from outside which I don't want.

    Yes you need some fresh air but I don't want warm air used to keep an exact set temperature. If it gets a little too cold, it should just shut off the AC compressor and/or reduce fan speed and wait for the outdoor heat to naturally migrate in (not to mention IR heat from the sun) which won't take long at all. There should at least be a setting, those who are extremely sensitive to temperature change and are willing to pay for it can have constant adjustment using mixed air. Others (like me) should have a option to allow temperature to fluctuate a little if that will be more efficient. I was hoping that Econ mode was that control, but it doesn't seem to be, maybe it is a little less aggressive but if it is I can't tell, based on the sounds that I am hearing I think it is still mixing in warm air in constantly changing ratios.
    Last edited: Aug 6, 2019
  14. Hoon

    Hoon Member

    As I said, outside was 60F so there no hot air to pull from besides the heater core heating up to make it to 78F early this morning. I think the heater is dumb enough to run it even in summer.

    I did turn off AC in the morning but I don’t think that changes anything.
    Last edited: Aug 6, 2019
    MPower likes this.
  15. ClarityBill

    ClarityBill Active Member

    I have also been frustrated with hot air coming from the vents on a 60F morning. Really would like to find a way to control the heater. My GOM EV range has dropped back to 42 miles, because I did not notice the heater was running.
    MPower likes this.
  16. Hoon

    Hoon Member

    Hey, does everyone else's Climate Control screen shows AC is not ON and not OFF? Is this a bug that's been fixed? When I first go to Climate Control, it doesn't show whether it's on or off. Also, yeah, it would be wishful thinking if Honda add at least another row of Heater ON OFF control. They should have treated the AC and Heater as equal energy consumers instead of thinking heat is free.

    Attached Files:

    Danks and 2002 like this.
  17. 2002

    2002 Well-Known Member

    Okay sorry yes that is another situation. I think that's true though with all climate control systems not just Clarity, at least any that I have driven. You can't turn heat on or off you can only set the temperature and the system decides if it needs heat or not. I had the same problem in my Prius, I would be sitting at a light and ICE would come on, quick glance at the display and I had plenty of SOC, then realized it's trying to heat the cabin so I had to lower the set temperature or turn the whole thing off. The system can't read our minds what we want so they really need a heat on off button.
  18. Mowcowbell

    Mowcowbell Active Member

    Yes, mine works the same way. Press climate button and neither on or off is lit on the screen.
  19. KentuckyKen

    KentuckyKen Well-Known Member

    Yes, mine too. I think that if you’re in auto mode neither indicates. You only see On or Off if you manually select them. I sometimes manually turn off AC and set the temp to Low to get outside air with no AC or heat. They must have just copied the gas-mobile system without taking the effort to make it EV friendly.
  20. ClarityBill

    ClarityBill Active Member

    Back to reliability... What is the basic warranty on the Clarity? Does something end at 36,000 miles? (I am currently at 32,000).

    Will Honda continue to do 'free' service bulletins after warranty expiration?

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