SOLVED- Unexpected ICE Turns On

Discussion in 'Clarity' started by AnthonyW, Sep 25, 2018.

  1. Ray B

    Ray B Active Member

    Hi Bill,

    No other hybrid/EV data comes out of the box. Just the Hybrid SoC%. The torque app has options to log every start up/shut-down as a single log file (I use .CSV when I download them), but you could check a box in the setup menu to append a log file when the down-time is less than 30 minutes; so if you step out of the car for a run to the store, it will allow you to continue the log-file when you start back up. You can also set it to ignore short trips (<0.5 miles). You don't have to 'start' a log file. It logs the data in the background, and then later you can save it to Google drive or whatever to access it.

    There is a TorqueScan plug-in available on the Google Play store that will apparently work with Torque to create a file of all of the sensor data that it has access to, so that you can then set up the special PIDs to log that data. The plug-in gets good ratings, but some of the negative comments lead me to believe that it may not work.

    Looking at this site ( leads me to believe that there are tons of available sensors through OBD. But I am not willing to spend ~$500 to get access to the data. lol.

    In my google searches and browsing the Torque app's forum postings, I get the impression that Honda hybrid/EV data is not easy to access with low cost OBD2 scan tools. Some success was reported on this forum with ScanGauge II, but I understand that any PID developments would mean sending the unit back for updates, which seems impractical. It also doesn't appear to have a means to log the data, which is a deal-breaker for me.

    Here's an example of a forum where people were trying to get PID codes for their civic: . I am jealous of the people that are able to view their Torque app on the head unit. I don't think that is possible yet for bluetooth scanners on 2018+ models.
    Cash Traylor likes this.
  2. Cash Traylor

    Cash Traylor Active Member Subscriber

    I have HH'd my headunit, and am considering acquiring a wifi based ODBII scanner to display this data real time and log it real-time. The HU (headunit/infotainment) doesn't care, and they're some side ADB data dumps available that interface with the "hidden" diag pages available. I have reached the peak of my "programming/dev" abilities on this and am now resorting to a "bounty" on the XDA forums for further hacking of the available data streams. There are likely some folks on this forum far more intelligent than I am that may figure out more available info. I am probably going to go back to the ANC unit first, as that is a unit I want to crack into for my audio system purposes. After that, I may revisit the ECU/BCU and other data streams over the ODB interface. There are a lot of smart people on this forum, give it time and the secrets will reveal themselves.

  3. ClarityBill

    ClarityBill Active Member

    I did not get back to my hill to check for engine braking, but I had an even 'better' experience. I left work with a full charge last night, started driving in EV mode to get the battery down. While I was still in EV mode, a car turned off the highway in front of me, the BRAKE alarm came up: and the ICE started (IN EV MODE). I did not hit the brake or the accelerator, or manually change mode.

    I am attaching a graph of the OBDII data during this time. I am not recording ICE temperature, but it appeared the engine continued to run (using gas, as my HV mileage decreased), until the warmup completed, and then went to an 'undocumented' HV mode. At first, the SOC on the battery kept going down, like it was in EV mode. After a while, the SOC stabilizes, like it went to HV mode, but the HV mode indicator did not come on. The system acted like it was in HV mode, and the ICE shut off when SOC started to go up. I was not sure what the car was doing, while driving, so I switched to HV mode after the ICE stopped (car still driving).

    I don't know if it ever would have gone back to EV mode on its own: I wanted to go to HV mode, so I switched that on, after the car seemed to be done with its unexpected behavior.

    The BRAKE experience was 'instantaneous': That may be the reason there is no evidence of 'engine braking' at low air flow.

    This event started between minute 5.9 and 7.1 on the attached graph. Datalog shows ICE RPM's start at minute 6.7

    Temperature shown on the graph is ambient temperature. RPM is ICE RPM divided by 100 to keep the scale consistent. Speed is road speed in MPH. Air flow is the mass air flow meter. The bottom axis is elapsed time in minutes.

    Attached Files:

  4. ClarityBill

    ClarityBill Active Member

    I had another experience of 'engine braking'. On the attached OBDII graph, the air flow drops well below 'operating level' on an extended decline. During minute 78 of the attached graph, the air flow is very low. During that decline, there was a period where the motor appeared to be 'disconnected' in the energy flow diagram, but still lighted.

    I am not convinced this is engine braking, but it seems an interesting piece of information. I will have to check if the OBDII offers a fuel flow parameter.

    Posted the OBDII for the entire trip on another thread, where I explained how I avoid angry bees.

    Attached Files:

  5. Mark W

    Mark W Active Member

    I read most of the posts in this thread. I can't say I understand all the science behind all of this. I still don't understand the decision to start the engine so often by the Clarity designers. I have owned a Leaf for over a year. It has regen braking of course. There are many times where I charge it to 100% and drive and brake. There has never been any issues with braking with that car. It has no ICE to start to dissipate energy. I get into it, press the pedal and go, press the brake to stop with no thoughts to how it's braking. The braking always seems natural to me. I think Honda has caused unnecessary "problems" with this design.
  6. bobcubsfan

    bobcubsfan Active Member

    Three days in a row I drove the same route in EV mode, not Sport. Battery fully charged. Two segments were downslope. Not steep but down. Came to two stop signs braked. Nothing happened. Made a right turn. The next segment was uphill. That's right UPHILL! Did not brake at all. The car glided to a full stop at the stop sign. ICE came on. About 2 miles later, ICE turned off. Then it came on again in the middle of a block. I too had a Nissan Leaf. Two of them as a matter of fact. Same experience as Mark W above.
  7. Robert_Alabama

    Robert_Alabama Well-Known Member

    I think we all can agree that using the ICE to dissipate excess regen energy was one of those "just because you could doesn't mean that you should" situations that Honda missed identifying in the design of this car. Honda didn't realize just how much owners of the Clarity don't like the ICE starting up when they have battery available that they would much rather use. However, we have what we have, it is what it is, whatever... I do think some proactive load placed on the car before regen is helpful when the car is fully charged (or nearly fully charged). My situation really threw me for a loop in that I had accelerated the car to 40 mph prior to stopping to make a left hand turn (not a downhill segment) which was causing the ICE. And I am not talking about aggressive braking being required to start the ICE. This car is just really sensitive as to how much regen it allows when it is near full charge. The defroster use for a minute prior to regen seems to fix my issue. I've had 3 days straight with no ICE at the same point that ICE was starting regularly (even with me trying to be soft on the brakes or regen paddle). I don't know that adding some load (heat or defroster) will help everyone as you have to have a recurring condition to be able to plan ahead a minute or so of load to help absorb the regen. But for me it was the recurring event that was bugging me. Again, I wasn't burning enough gas to really complain about (about a gallon or so total in 2-3 months), it was just the annoyance of feeling it wasn't necessary. This may not help anyone, but hey I tried. I really enjoy my Clarity. I'd love to help others feel that way about theirs.
    Cash Traylor likes this.
  8. bobcubsfan

    bobcubsfan Active Member

    I agree that Honda really messed up, and worse, they refuse to acknowledge it fix the issue. Does anyone know how to install a kill switch for the ICE? I would love to have control over it.
  9. Atkinson

    Atkinson Active Member

    Low intake air flow may be due to the intake cam timing changing to close the intake valves later.
    This allows the engine to reduce power output without associated throttling losses.
    Throttle open with late intake close pushes mixture back into intake manifold and net airflow (and fuel consumption) is reduced for a specific RPM.
    May not be related to this specific instance, but I wanted to point this out so results aren't skewed.
    Cash Traylor likes this.
  10. insightman

    insightman Well-Known Member

    This sounds to me like the starter motor/generator is applying torque in opposition to the rotation of the engine, hence my claim that the two are fighting. Here is the part of my Clarity mode chart that illustrates these combatants going at it:


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