We Put a 2024 Toyota Corolla Ascent Hybrid on the Hoist
Hybrid vehicles are becoming increasingly common on Australian roads, but there is still a lot of uncertainty about what is actually involved in servicing one.
Does a hybrid need a different type of service?
Does it still need normal engine servicing?
What about the hybrid battery?
And perhaps the question we hear most often:
Does a hybrid have to go back to the dealership?
At AutoSavvy Mechanical in Noosaville, we’re preparing for the rapidly growing number of hybrid vehicles entering the local vehicle fleet.
So when this 2024 Toyota Corolla Ascent Hybrid, with approximately 25,000 kilometres, came into the workshop, we thought it was the perfect opportunity to put it on the hoist and show exactly what is involved.
The first thing to understand is that a hybrid isn’t simply an electric car with a small petrol engine attached.
The Toyota Corolla Hybrid combines a petrol engine with electric motor-generators, a high-voltage traction battery and sophisticated electronic control systems.
And underneath all that technology, there is still a conventional mechanical vehicle.
The engine still requires appropriate servicing.
There are still:
- Engine oil
- Oil filters
- Cooling systems
- Brakes
- Suspension
- Steering
- Wheel bearings
- CV joints
- Tyres
- Air conditioning
- Windscreen wipers and washers
- A 12-volt battery
- And plenty of other conventional mechanical components.
One of the most interesting things we inspected on this Corolla was something that isn’t found on a conventional petrol Corolla:
The hybrid battery cooling filter.
Located underneath the rear left-hand passenger-seat area, this small filter forms part of the cooling system for the hybrid vehicle’s high-voltage traction battery.
The battery needs to be kept within an appropriate operating temperature range.
The cooling system draws air from the passenger compartment through an intake, with the filter helping prevent dust, dirt, lint and other debris from entering the battery cooling system.
And look at the filter we removed from this Corolla.
This is a component that can easily be overlooked if a technician is unfamiliar with hybrid vehicles.
Toyota’s technical maintenance information specifically identifies the HV battery intake filter as an item to inspect, with cleaning or replacement required if it becomes clogged or damaged.
That’s a very good example of why a hybrid shouldn’t simply be treated as an ordinary petrol vehicle.
Why does the filter matter?
If airflow to the traction-battery cooling system becomes restricted by dust, dirt or other debris, the cooling system has to work harder.
Keeping the intake and filter clean helps maintain proper airflow through the battery cooling system.
And for a workshop, it’s a relatively simple inspection that can potentially prevent a much more complicated problem.
What Else Is Different About a Hybrid?
The battery cooling filter is only one of the additional areas we need to consider.
1. High-voltage traction battery
Unlike the normal 12-volt battery found in conventional vehicles, the hybrid has a high-voltage traction battery that forms part of the vehicle’s propulsion system.
This is a completely different system and requires appropriate safety procedures.
We don’t treat high-voltage components casually.
Where high-voltage work is required, the correct procedures, equipment and technician qualifications are essential.
2. Hybrid battery cooling system
The traction battery has its own cooling-air system.
On this Corolla, that includes the intake, filter and cooling blower arrangement.
The filter is something we can physically inspect and photograph during servicing.
Toyota’s parts information for the Corolla identifies the battery cooling blower, HV battery intake filter and associated ducting as separate hybrid-system components.
3. Inverter and power electronics cooling
The hybrid system also contains sophisticated power electronics.
The inverter/converter system manages electrical energy between the battery, electric motor-generators and the rest of the hybrid system.
Toyota’s Corolla parts information identifies a separate inverter cooling circuit, including a coolant reservoir, hoses, hybrid water pump and hybrid radiator.
4. Regenerative Braking
The braking system is another area where hybrids differ from conventional cars.
When the vehicle slows down, the electric motor can operate as a generator, recovering energy and sending it back to the traction battery.
That’s called regenerative braking.
But the car still has conventional mechanical brakes.
So we still inspect:
- Brake pads
- Brake discs
- Calipers
- Brake fluid
- Brake lines
- Brake operation
- Uneven wear
In fact, because regenerative braking can reduce the amount of work done by the conventional friction brakes in some driving conditions, regular inspection remains important.
5. Hybrid Diagnostic Scanning
A modern hybrid isn’t something we should diagnose simply by looking under the bonnet.
Electronic diagnostics are an important part of the inspection, including diagnostic scanning of the vehicle’s systems and a traction-battery health check.
At AutoSavvy, our approach is to use appropriate diagnostic equipment to identify faults and assess the vehicle’s systems.
If a fault is identified in a system that requires specialist equipment or procedures outside our workshop’s capability, we’ll tell the customer.
So What Would We Check on This 25,000km Corolla?
Engine
- Engine oil and filter
- Coolant
- Hoses
- Drive belts
- Oil leaks
- Coolant leaks
- Engine operation
Hybrid system
- Hybrid diagnostic scan
- Warning codes
- Hybrid system operation
- Traction-battery health assessment where appropriate
- Battery cooling intake
- Battery cooling filter
- Battery cooling blower and ducting
- Visible high-voltage wiring and connections
- Hybrid-system cooling components
Inverter cooling
- Coolant reservoir
- Coolant level
- Hoses
- Water pump
- Radiator/cooling components
- Signs of leaks
Brakes
- Pads
- Discs
- Calipers
- Brake fluid
- Brake lines
- General braking operation
Suspension and steering
- Bushes
- Ball joints
- Struts/shock absorbers
- Steering components
- Wheel bearings
- CV joints and boots
Underneath the vehicle
- Oil leaks
- Coolant leaks
- Exhaust system
- Suspension
- Steering
- Brake lines
- CV boots
- Underbody components
- Tyres
12-volt battery
And don’t forget the little battery.
A hybrid still has a conventional 12-volt electrical system, and its condition remains important.
Does a Hybrid Have to Go Back to the Dealership?
Not necessarily.
There are specialised aspects of hybrid technology that require appropriate equipment, knowledge and safety procedures.
But much of the vehicle’s routine mechanical servicing remains very familiar to an experienced mechanical workshop.
Routine hybrid maintenance as broadly similar to conventional vehicle maintenance and includes engine oil servicing as part of hybrid maintenance.
At AutoSavvy Mechanical, our philosophy is simple:
We’ll carry out the work we’re equipped and qualified to perform, and we’ll tell you honestly when something requires specialist attention.
Why AutoSavvy Is Getting Ready for the Hybrid Generation
Hybrid vehicles are becoming a much larger part of Australia’s new-car market.
That means independent workshops need to understand these vehicles now — not several years from now when hybrids are already a major part of the local vehicle fleet.
At AutoSavvy Mechanical in Noosaville, we’re building our knowledge, equipment and servicing procedures so we can continue looking after our customers as vehicle technology changes.
And this Corolla gives us a chance to demonstrate exactly what that means.
This Corolla Has Given Us a Great Look at Hybrid Servicing
At approximately 25,000 kilometres, this Corolla is still a relatively young vehicle.
But it demonstrates something important:
A hybrid service is about more than changing the engine oil.
AutoSavvy Mechanical — Hybrid Servicing Noosaville
If you own a Toyota Corolla Hybrid, Kluger Hybrid, RAV4 Hybrid, Camry Hybrid, Yaris Hybrid, Lexus or another hybrid vehicle and need servicing, inspection or mechanical repairs, talk to AutoSavvy Mechanical in Noosaville.
