For suspecting some thing wrong we must be knowing its complete way of working. We can try to understand that together.
Hope u have got your routine maintenance before further troubleshooting into EV mode problem which includes
1) engine oil change 0W for hybrid engine
2) cleaning of air filter and may be MAF sensor(does make lot of difference in attaining better mileage)
3) cleaning spark plugs
4) cleaning throttle body
5) Cleaning the filters of battery bank vents behind rear seat floor (Not sure about Axio 2014 configuration)
6) Clearing any old maintenance codes in ECU
1) are u still in sialkot?
2) as per weather history from internet it was raining in sialkot on 22nd Feb, did u let the hood open to rain by any chance?
3) did u wash its engine? if yes then i think moisture detector in Hybrid Synergy drive area may be preventing electric motor to kick in. In this case use your car for 2 to 3 days and then reset its ECU from reconnecting positive terminal of battery.
4) have u installed any High power consuming electronics on your car like HID's or Sound System etc?
5) is your car battery depleting too? if it is then its good as its completing its cycle.
6) is your fielder 4x4? may be 4x4 is engaged inadvertently by a kid or someone? or any other mode like traction control engaged?
hope every question mentioned above will have your positive answer. Now coming to the point:
From little search on google i read about EV mode from Toyota Hybrid Manual that
"This mode allows you to drive in residential areas early in the
morning and late at night, or in indoor parking lots etc. without
concern for noises and gas emissions.
Your Toyota is designed to achieve the best possible fuel economy during
normal driving (using the gasoline engine and electric motor [traction motor]).
Driving in EV drive mode more than necessary may lower fuel economy."
EV mode is for very short distances and hybrids are better in city areas then on long routes. Engagement of EV mode has some following pre-requisites in general (Not exactly specific to AXIO 2014):
1) The hybrid control system is extremely hot.
2) After the vehicle has been parked in an extremely hot environment, driven at high speeds or the vehicle is climbing a slope, etc.
3) The hybrid control system is extremely cold.
4) After the vehicle has been parked in an extremely cold environment (approximately 0°C or less) for a long period of time.
5) The engine is warming up.
6) The SOC (State of Charge) of the HV battery is low.
7) The HV battery SOC displayed on the hybrid system indicator display is low.
8) The vehicle is being driven at a speed higher than the specified value.
9) The vehicle speed is approximately 30 km/h or higher.
10) The accelerator pedal is being fully depressed or the vehicle is climbing a slope.
11) The defroster is on.
12) DTCs are stored.
If any of these condition doesn't meet then EV mode will engage
In hybrids we just have to look for overall consumption and not its algorithm as it will work as per design which cant be understood so easily by its users. Now the small difference between EV and ECO mode as u asked:
EV (short for Electric Vehicle) mode is only available in hybrid vehicles and is much more particular in its uses than other driving modes. If a vehicle is running in EV mode, the vehicle is only pulling power from its battery. This results in the potential for very efficient driving, but it also means the vehicle in question doesn’t have access to as much power as it normally would. That’s why EV mode typically works for just up to one mile and is only applicable under certain conditions at very low driving speeds. Due to these restrictions, it’s best to reserve EV mode for driving extremely short distances that don’t require much speed such as moving a vehicle out of a garage or driving in a parking lot.
Drivers need to be especially careful when utilizing EV mode because it can make vehicles practically silent. This means pedestrians, bikers, and other vehicles may not hear an approaching vehicle while it’s in EV mode. Therefore, it’s paramount that you pay close attention to your surroundings when using this feature.
ECO mode is one of the more obscure driving modes available. As many drivers correctly assume, its intention is to make your vehicle run more economically than it would in its normal driving mode; but what many drivers don’t know is how it achieves this effect. ECO mode ultimately aims to increase fuel efficiency by reducing acceleration levels, which—although it doesn’t actually change the vehicle’s engine power—means the accelerator will not be as sensitive and, therefore, not use as much fuel when pressed at the same interval. This feature can be useful during stop-and-go city driving when you may not want your accelerator pedal to be particularly sensitive. ECO mode can also regulate the power provided to your vehicle’s air conditioning system and other accessories to further increase fuel efficiency.
It should be noted that some vehicles come with an ECO indicator light that is very different than the ECO mode button we’re currently discussing. While putting your vehicle in ECO mode actually changes certain components within the vehicle, the ECO indicator light simply tells you if you’re driving in an economic fashion.
ECO mode is also available in gas-only vehicles.
All will be good inshallah for all of us. Enjoy your ride its indeed a beautiful car u have.