mite66
Posts: 6
Joined: Tue Jul 14, 2015 10:50 am
Delivery Date: 14 Oct 2014
Leaf Number: 494939

Power gauge false reading

Fri Nov 25, 2016 1:21 pm

My 2013 SV has been at the dealer for two weeks now because they can't find the reason for my power meter gauge false reading problem.

Long story short: they replaced the traction motor on it (motor only, not inverter nor charger) because of a small noise during acceleration/deceleration. It did solve the noise issue but when I took the car back, I noticed that my power gauge meter was no longer accurate. Running 70mph on highway would give me 5 kw reading or so. I even ended up a 40 miles trip having a 14 miles/kWh average (!). Took it back to dealer, no relevant DTC.

So obviously something went wrong during the motor swap operation. I've been reading the service manual in an effort to find a clue on this behavior and found that a DTC can be thrown in this situation but only if "The difference between the estimated power consumption calculated based on a torque value from VCM to the traction motor inverter and the actual power consumption calculated based on a high voltage battery voltage and current is 54 kW or more."

Which is ridiculous in my point of view, I mean a difference of 54 kW is really huge.

I was suprised to see that the motor power consumption is calculated and not measured, the manual says: "POWER CONSUM (MOTOR) kW Displays the traction motor estimated power consumption calculated by VCM from the traction motor torque and vehicle speed."

So since my speedometer reading seems to be ok, I assume that the reading of my traction motor torque might be wrong.

Anyone here have a clue of where to look to solve this ? I want my Leaf back, 2 weeks driving an ICE car is really painful :-(

arnis
Posts: 713
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: Power gauge false reading

Sat Nov 26, 2016 6:44 am

Maybe then used newer electric motor that has different windings compared with older Leaf.
You should feel very slight acceleration weakness from standstill and a little bit more power at medium speed.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

mite66
Posts: 6
Joined: Tue Jul 14, 2015 10:50 am
Delivery Date: 14 Oct 2014
Leaf Number: 494939

Re: Power gauge false reading

Mon Nov 28, 2016 7:25 am

arnis wrote:Maybe then used newer electric motor that has different windings compared with older Leaf.
You should feel very slight acceleration weakness from standstill and a little bit more power at medium speed.


I hope not, I mean that would have been a rooky error. Although, I did notice that their are two part number for the traction engine. So if it is indeed the case, I guess they simply would need to perform some firmware upgrade so that the reading match the new winding.

mite66
Posts: 6
Joined: Tue Jul 14, 2015 10:50 am
Delivery Date: 14 Oct 2014
Leaf Number: 494939

Re: Power gauge false reading

Thu Dec 01, 2016 9:54 am

The dealer called me yesterday saying that they might need to replace the motor again. I guess that arnis nailed it with his theory of two different motor winding.

Now I told the dealer that they might only need to reprogram the VCM or maybe replace it, but in both case, it should be a lot simpler than swapping the motor again.

They will check with Nissan Tech Line and get back to me.

arnis
Posts: 713
Joined: Sat Jan 23, 2016 3:21 pm
Delivery Date: 23 Jul 2014
Leaf Number: 015896
Location: Estonia, Europe

Re: Power gauge false reading

Thu Dec 01, 2016 11:21 am

:lol:
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

mite66
Posts: 6
Joined: Tue Jul 14, 2015 10:50 am
Delivery Date: 14 Oct 2014
Leaf Number: 494939

Re: Power gauge false reading

Wed Jan 11, 2017 1:37 pm

This journey came to an end yesterday after almost two months without my beloved Leaf.

The technician explained to me that at some point during the motor replacement procedure, he needs to enter the serial number of the new engine using his Consult computer. He said that when he did it the first time (two months ago), he got some kind of feedback saying "completed" or something like that.

It turned out that he tried again this step last Monday but did it differently than what the procedure is asking for and this time, he got his "completed" feedback but also some kind of code which is now considered important in this process. Et voila, according to him, the problem is solved. I will know more this evening when I'll have the time to hit the highway and give it a try.

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