Possible 4WD fault?

jaapv said:

Steepndeep said:

Yes, if it is not enough with battery power then I need the ICE obviously. Problem is that I do not floor the pedal at all, rather gently presses it to 25% level. And the powermeter on the dashboard hardly moves at all. Still the ICE starts.

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You say -20. Aren't you confusing the power demand with the ICE starting up for heating purposes?

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It crossed my mind too. But he said it only happens when backing up into his driveway, as he first makes a full stop then.

I feel that we may be over simplifying the way BLDC (Brushless Direct Current) motors work and in particular the difficulties that may exist in starting the motor going from standstill.

https://en.wikipedia.org/wiki/Brushless_DC_electric_motor

It is my understanding that the timing of the electric pulses needed to turn the motor rotor are hard to work out until the motor is turning.

Therefore no way is infinite torque or indeed quoted maximum torque likely to be available at a standstill, and I am sure that there must be a built in fail-safe to limit current (power) and temperature of the motors of the PHEV.

I am sure that the forum discussed the way all this worked in its early days, please can the 'modern electronics' experts enlighten us.

How does the PHEV start from it's 'motor stall' zero speed condition, on that first bit of rotary motion?
And what effort can it put into it.

Nobody has explained what the PHEV is supposed to do once one wheel is spinning freely. I think most other electronic governed 4X4s
would apply the brake to that one wheel to get cross axle traction.

anko said:

sas1 said:

I don't understand ...

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I do. Something like Moore's Law: If there is a remote possibility of misusing a product there will always be somebody doing so... :twisted:

@Anko @jaapv

My bad writing confuses you on the -20 degrees. I live in Stockholm and we now have +25 C. I first described that I back up and even with gentle accelerator push and almost 0 power indication on the powermeter the ICE starts. Then I attempted to write an example that if this happens in wintertime with -20 degrees and the ICE runs for only 2 seconds, that this is the most polluting way for any ICE to run.

Continuing on the topic on ICE start and on pulling a trailer up a ramp. Maybe ian4x4 is onto something. I tried to unscientifically see how much I actually press the gaspedal towards the floor whilst backing up slowly on my drive way. Unscientifically as I did not really meassure but just felt how much I tilt the foot towards the floor. Turns out that I actually tilt the foot roughly as much as when going on the highway in a slight incline at 110 kph and the powermeter is just on the border towards the white field, ICE does not start. So at high speed on the car the same pedal input gives power on the border to white on the powermeter but at crawlspeed the powermeter hardly moves at all. I have no idea what the powermeter actually meassures. I would assume it meassures power fed INTO the e-motors but then it does not make sense to start the ICE when powermeter does not show any power at all. Anyone having any idea on what goes on??

Errr...no. I must confess that I can't really follow your drift. The accelerator is really only a potentiometer controlling input into the computer, so the exact position is only a part of the complicated powerplay in the car.

Steepndeep said:

My bad writing confuses you on the -20 degrees. I live in Stockholm and we now have +25 C. I first described that I back up and even with gentle accelerator push and almost 0 power indication on the powermeter the ICE starts. Then I attempted to write an example that if this happens in wintertime with -20 degrees and the ICE runs for only 2 seconds, that this is the most polluting way for any ICE to run.

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Although the -20 deg C initially did trigger another line of thinking (same as Jaaps), this was what I eventually made out of it

Steepndeep said:

Continuing on the topic on ICE start and on pulling a trailer up a ramp. Maybe ian4x4 is onto something. I tried to unscientifically see how much I actually press the gaspedal towards the floor whilst backing up slowly on my drive way. Unscientifically as I did not really measure but just felt how much I tilt the foot towards the floor. Turns out that I actually tilt the foot roughly as much as when going on the highway in a slight incline at 110 kph and the power meter is just on the border towards the white field, ICE does not start. So at high speed on the car the same pedal input gives power on the border to white on the power meter but at crawlspeed the power meter hardly moves at all. I have no idea what the power meter actually measures. I would assume it measures power fed INTO the e-motors but then it does not make sense to start the ICE when power meter does not show any power at all. Anyone having any idea on what goes on??

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Like I wrote myself a bit earlier, at standstill E-motors are very inefficient and maybe they need much more power to start spinning than they do to keep spinning. Does this stop at 1 RPM or at 500 RPM? That I do not know.

But now imagine the Power meter does not show (electrical) power consumed but (mechanical) power put out at the wheels. Ignoring the very big losses at very low speed. This would explain why the power meter hardly moves at very low speed (as output is still limited by max torque and current RPM, the last being very low at low speed), while the ICE engages.

It would be in line with the fact that the power meter does not reflect power used for charging the battery or power used for heating / cooling. And also, when coasting, the power meter is at 0, while I know for a fact that power is fed into the motors. Finally, the power meter is also not a good indication for fuel usage, so why should it be a good indication for electricity usage?

I will monitor my power meter and other dials for a while, with this thought in mind. See if this confirms this theory of mine.

I think it will be easier to see if the car has a problem if Baingyl films the next try.

http://www.mitsubishi-motors.com/en/spirit/technology/library/s-awc.html

Example of Outlander PHEV
(Standard Equipment with All Model)

S-AWC used in Outlander PHEV has the integrated control function of Twin Motor 4WD and AYC which controls the driving force distribution between front and rear wheels and between right and left wheels. And TWIN Motor 4WD controls the driving torque and the regenerative braking torque by front and rear electric-motors respectively. AYC controls braking force for each wheel respectively. Moreover, ABS and ASC is controlled optimally. S-AWC achieves a faithful handling to the driver's operation and enhanced stability, and supports the driver safety, the comfortable vehicle characteristic and the efficient vehicle driving.
Driver can select two operating mode by 4WD LOCK switch: "NORMAL" is for usual use and "4WD LOCK" is for higher traction ability.

I have just left my car at the mitsubishi workshop for investigation. Yesterday i did another attempt trailing the car at the ramp, this time with antiskid carpets under each wheel. I have filmed it and will post it soon...

How it ended?

A Volvo XC70 had to assist this time and pull the boat trailer out of the lake.... :evil:

OK, here goes.... Unfortunally the cameraman is my 72year old father who accidentally pushes the wrong buttons (ie volume up´n or down when filming, which then forces the camera app to stop recording and switch to photo mode! So not so much available video footage as i had hoped.

Atlast I have figured out what is causing the "clonking" metallic sound when reversing... It´s from the boat trailers brakes, when reversing slightly uphil, the trailers weight pushes against the hitch causing the trailer brakes to react and creating the clonk sound. So atleast that is good news (i guess) that there is nothing wrong with any of the motors.

Mitsubishi mechanic told me that they did fix the LDW not working after front windows was recently replaced however the did NOT investigate the engine or perform and troubleshooting due to the fact that chief technician at Mitshubishi Sweden has said that the new recommended max towing weight for Mitsubishi Outlander is maximum 1000KG... Hence "there is nothing wrong".... (i told him that i do not agree or accept that "solution")... If the specs says 1500kg then it is 1500 no more no less.

So i went to the sales guy and asked him what todo if he has sold me a 4WD SUV wich is unable to pull my boat trailer! He told me to wait until Mitsubishis head technician who perhaps has an alternate solution, perhaps new firmware or some kind of fix to boost pulling performance? I dont know...

Only cars so far able to tow my trailer out of the lake is a Subaru and now also a Volvo XC70

As you can see in the video there is a "hump" just in front of the rear wheels, perhaps if that one is dug away it could help a little, although the Volvo and Subaru did not mind... The skid plates helped a little but where too short.

https://youtu.be/H_imGaSZ1B8

Absolutely shocking i must say anyone else has this experience?

Very interesting video! To me it seems that the 4WD implementation does not play too well here. If you got some power on the rear wheels then you would not get stuck. It looks strange that the torque is not moved to the rear wheels when the front wheels are spinning. I have noted this maybe once or twice over two years of ownership that the front wheels will go into spinning mode too easily.

OK, you have a slight "hump" as shown in the video but that should not prevent you from getting your boat up from the lake. I do hope that you get good support from Mitsubishi. I believe that some 4WD software tweaking could improve and solve the situation. On the negative side, Mitsu are deadly slow with the SW updates. Normal cadence seems to be max one update every 12 months.

Yes that was indeed an eyeopening video. A pity you could not see the Volvo from start so we could see whether it also spun the front wheels for a short while. Regarding the dealer saying you should only pull max 1000 kg that is absolutely bull. I checked the Mitsu website and they have not changed any info there, still 1500 kg. And with due respect, changing that figure would result in all sorts of lawsuits. Ask them to give you a written official statement on this new weightrating and give that to a lawyer or Konsumentombudsman.

Now for some speculating on what is really happening here.

I believe the Volvo has a Haldex Gen 4 or 5 automatic diff (actually a diff-lock and the older generation is deemed better than the new) but no front or rear limited slip. Mitsu has S-AWC (whatever that really is), maybe limited slip (as discussed in this thread but no known % ratio on the slip) and 4W-Lock (in software). Given similar tyres and car weight the Volvo would slip the front wheels for a short while and then the Haldex kicks in locking the center diff. With similar grip between right and left rear wheel it apparently pulls the boat up just nicely. Which it should do.

The Mitsu spins the front wheel and here it gets interesting with brushless e-motors and 4W-Lock. As someone pointed out earlier in this thread (which I did not know) the e-motor has very little power at slow speed. Question then, how does the 4W-Lock work?? Mitsu states that it simulates a center diff-lock buy having 50% of power to front wheels and 50% to rear wheels. But that is simply wrong. If you e.g. have a center diff-lock and one front wheel in the air and then start the car the drive shaft to front and rear diff will be locked and rotate with same speed. As the front wheel is in the air it will spin freely consuming almost 0 power. Whereas the rear wheels being stuck to the ground will absorb almost 100% of engine power propelling the car forward. So 50-50 is not a good simulation.

Now in the boatcase here, one frontwheel spins and hence the front engine gives very little power. If the rear engine matches the front engine then you will get very little power to the rear engine :? On the other hand if the front engine matches the rear engine and rear wheels are stuck you get very little power from rear and then matching on the front. Both cases seem bad.

Again I do not know the actual sw implementation but I think that in a standstill situation with one or two wheels on slippery surface it is very hard to find a sw solution. You need mechnical difflock, unfortunately. Would be nice to get a written Mitsu statement here.

However as soon as you get going at some speed above crawl I think the system is OK. So OK to go fast offroad but do not get stuck;-) When we get the first ice here in Sweden I can test the various situations on my steep driveway.

If only I would be able to reproduce these circumstances.... My OBDII tools allow me to monitor Torque Requested and Torque Produced as well as RPM for both front and rear motors.

Steepndeep said:

As someone pointed out earlier in this thread (which I did not know) the e-motor has very little power at slow speed.

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Why would that be a problem? Power is only needed when you want to go faster. If you want to get going, all you need is torque. And torque should not be an issue. Unless the SW works against us ....

Steepndeep said:

Again I do not know the actual sw implementation but I think that in a standstill situation with one or two wheels on slippery surface it is very hard to find a sw solution. You need mechnical difflock, unfortunately.

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Don't see why you would need a mechanical diff lock perse. Even with three wheels spinning freely, you should be able to get going if only the SW was smart enough to apply the friction brakes to those three wheels. Don't know if it is, as I have not been in that situation myself.

The Volvo XC70 also did spin the front wheels a little, but when reversing and having some speed (as i also did several times with my PHEV with only right front wheel spinning) ALL four Volvo wheels seemed to kick in and PULL the trailer out with ease.

Today i will contact Mitsubishi Sweden and ask for a written statement for the new towing limits (if they have changed officially or not).

Closing in on the best fishing period of the year (autumn northern pike fishing) i am worried that i will not dare to use my car as towing vehicle with the risk of getting stuck in the middle of nowhere with damp conditions autumn leaves and all sorts of muck making this so called off road vehicle come to a stand still. :evil: :roll:

Anyone here who thinks this problem can be solved with firmware tweaks in the near future? Or is it time to throw in the towel and buy a real off road towing car -perhaps a Volvo XC70...?

I know these are Freelander videos but it is the best I could find to explain and demonstrate how traction control should work in various off road situations.

https://www.youtube.com/watch?v=ZNpzTnj7YMA

https://www.youtube.com/watch?v=y4DTtMDKy0E

The original OP PHEV video does not seem to show any real traction control across the axle???

Last year I was on blue ice with the front wheels and on snow with the back ones. Slight incline down. The car was able to move backwards, but with excessive frontwheel spin and only just. That seems to confirm that the differential simulation by 4WD drive lock does not function well from standstill.

Indeed. With a true locking diff, all available torque is automatically directed to the wheels / axle that have grip, as a wheel / axle without grip cannot consume any torque and the torque must go somewhere ....

(for those in doubt: all torque produced by an ICE goes to the side of the crankshaft to which the gear box is connected. No torque goes to the loose end on the other side ).

In case of the PHEv, when one axle has no grip, the torque of the motor must be reduced or will result in excessive wheel spin. It cannot be directed to the other axle. This means the car will have to do the trick with only the amount of torque available from the other motor....

You can wonder if one motor will be enough to get the car + boat going.

Having looked again at the video, I wonder if the trailer nose weight is relieving the front wheels of traction (lack of weight) and therefore the remaining rear motor is just not strong enough to pull trailer.

The normal 4x4 shown pulling successfully has the advantage of a locked centre differential and therefore has full power (and torque)available to either axle (whichever has traction). If it had an auto gearbox and torque converter then it would be ideally suited to this task.

I do wonder if a little bit of slip in the rear wheels of the Outlander may have got the motor (and therefore the car) moving, as there must be electronics to stop damage to motor due to overcurrent when stalled.

another thought -- I do wonder if a couple of bags of sand on the bonnet may solve the problem, not very elegant I know but could make the axle loads more equal and allow the front motor to do its job.

Or a couple of people sitting on the back of the boat