Hybrid and electric vehicle service

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feature Hybrid and electric vehicle service

As the fleets grow, so grow your sales opportunities

By Jacques Gordon

This year, the Corporate Average Fuel Economy (CAFE) standard for passenger cars increased for the first time in decades, from 27.5 mpg to 34.1 mpg. By model year 2025, the CAFE standard will increase again to 54.5 mpg. To reach these fleet average numbers, almost every automaker selling cars in North America has already introduced at least one model with a hybrid-electric or all-electric powertrain, and they are all working hard to increase the market as well as develop the technology.

The hybrid fleet is expected to grow dramatically over the next decade, and the odds of a hybrid car pulling into your driveway are increasing each month. If you’re not already working on hybrid or plug-in vehicles, it’s the time to prepare for some new service opportunities.

Normal maintenance of a hybrid car is not much different from a conventional vehicle: it has an engine, so it still needs a periodic oil change and a new air filter and eventually new spark plugs, too. Pure electric vehicles don’t have an engine, but just like hybrids, they still need new cabin air filters and wiper blades, brakes, shock absorbers, and of course tires. But before you agree to service a hybrid or electric car, there are some things you need to know that will help you decide which maintenance services you want to offer, and some things that are important to the safety of your technicians and your customers’ cars. Specific oil change recommendations

One reason hybrids get such good gas mileage is because they almost never get zero miles per gallon. Unless the engine is charging the battery or running the air conditioner, it automatically shuts off whenever the car stops moving.

This stop/start feature confuses most first-time hybrid drivers because they think the car has stalled. Many are also surprised when the car starts moving again once they release the brake, even if the engine is not running. When techs drive hybrids into the shop and the engine stops, they quickly figure out that the shift lever must be in Neutral or Park to prevent the car from moving.

What some techs don’t figure out right away is how to make sure the car is turned off, especially since most hybrids have a Stop/Start button instead of an ignition key. If the car is turned on, the engine will start when the battery’s state-of-charge falls below a pre-programmed percentage. The only way to prevent this is to make sure the car is turned off and the gauges and display screens are all dark. Imagine the horror of hearing the engine start with the car on the lift and the oil drain plug removed (it has happened).

Every car manufacturer recommends the type of motor oil that should be used in their engines, and those recommendations are quite specific for hybrids. Most are designed to use 0W-20 motor

After the driver has stopped the car, Honda’s “AUTO STOP” light warns that the engine will start again once the brake pedal is released. In the auto industry, there is no standard design for this warning light; Toyota uses a “READY” icon, while Ford lights up a little picture of a car. Using the wrong motor oil in a hybrid engine will not only reduce gas mileage, but also may cause higher emissions, no-starts and even engine damage.

oil, and if heavier oil is used it will decrease the car’s gas mileage. Before starting brake work on any vehicle with a computerThis will make your customers unhappy (they pay close attention controlled brake system or electronic parking brake (hybrids are to gas mileage), and it also can have more serious consequences. not the only vehicles with brake-by-wire), it is absolutely critical For instance, if heavier oil is used in a third-generation Toyota to make sure the system is completely deactivated. Some of these Prius (2009-2015), the timing chain tensioner won’t pump up systems run a full-pressure self-diagnostic test while the car is properly. The timing chain will rattle and maybe even jump a turned off. If this happens with the pads removed, it will damage tooth, which would cause serious engine damage. the system and/or injure the technician.

Using the correct quantity of oil is also critical on a hybrid On some cars, deactivating the brake system is as simple as vehicle. Excess oil increases the amount of oil fumes drawn manipulating the ignition key and brake pedal in the proper into the Positive Crankcase Ventilation system (PCV), and sequence, while on other cars it must be done with a scan tool. A those fumes flow past the engine’s airflow sensor. If the sensor scan tool may also be needed for bleeding the hydraulic system. becomes fouled with oil, the Powertrain Control Module (PCM) Not all scan tools have the necessary capabilities, so make sure will turn on the Check Engine light. Since the engine is already you have the proper equipment and complete service information running when the fault is detected, the PCM on conventional before accepting a brake job. cars will substitute different data to operate the engine, but on most hybrids the PCM won’t even start the engine if that sensor Low-rolling-resistance tires isn’t working properly. Even if you’ve never sold tires for a hybrid or electric vehicle, Brake system service tires. Most of a tire’s rolling resistance comes from the energy

The brakes on a hybrid or electric vehicle often require replacethat’s needed to deform it at the bottom as it flattens into a contact ment long before they wear out. To understand this, and to patch. The remaining resistance comes from tread squirm. To understand the service opportunities available to you on these reduce that energy requirement, low-rolling-resistance tires use vehicles, it helps to understand regenerative braking. different rubber compounds and different construction. They

A Direct Current (DC) motor is the same thing as a DC also tend to be lighter than conventional tires and have shallower generator; the only difference between them is the direction of tread depth. current flow. A hybrid vehicle has at least one motor/generator.. Like every other tire in the world, low-rolling-resistance tires

When the brake pedal is pressed, the PCM switches the curare a compromise between ride quality, handling and tread rent flow, turning the motor into a generator that is driven by wear, but most hybrid drivers care more about the tire’s energy the motion of the car. efficiency rating. General Motors Corp. says a tire can impact fuel

Even though the car is slowing down, much of the energy that economy by 4% in the city and 7% on the highway, and they’re was used to put the car in motion (kinetic energy) is recovered and investing heavily in on-going tire energy efficiency research. stored in the battery as electrical energy. This is called “regenerative While the U.S. still has no energy efficiency rating for tires, some braking,” and it’s the main reason hybrid vehicles get such good other countries do and so do some of the tire manufacturers. If gas mileage: energy is recovered instead being converted to heat your customer has already done his own research, he will know by the brakes and simply dissipated into thin air. which tires have the best rating.

So when you press the brake pedal on a hybrid or electric However, don’t be surprised by hybrid owners who are happy vehicle, the PCM uses the generator to slow the car. It could to exchange a bit of gas mileage for better handling. As you might actually stop the car completely, but generators work unevenly at low speeds and the last few yards of deceleration would be very jerky. So at about 5 mph, regenerative braking ends and the PCM finally applies the hydraulic brakes. That means in normal driving the brakes are hardly ever used and never used at speed, so they never get hot.

As a result, seized calipers and rusted brake rotors are common on hybrid and electric vehicles, especially in rust belt states. It’s also common for brake pads to delaminate or be stripped off the backing plate. This is why pads, rotors and sometimes even

you probably already know they use special low-rolling-resistance calipers need to be replaced long Road salt ruined the rotors on this Prius hybrid long before the brake pads wore out. Unless

the driver panic stops, the brakes are not applied until vehicle speed is below 5 mph, so the

before the brake pads actually rotors rarely heat up enough to dry out. When the caliper squeezed the rotor on the right, the wear out. friction material was actually ripped off the brake pad backplate.

imagine, low-rolling-resistance tires are not performance oriented, but some hybrid vehicles are a lot of fun to drive when pushed hard, and those customers may opt for a more performance-oriented tire.

When new low-rolling-resistance tires are installed, make sure to tell your customer they may notice a reduction in gas mileage, otherwise they’ll come back asking what you did to their car. As tire tread wears down, rolling resistance can decrease by as much as 20%, so the customer’s gas mileage will gradually improve as the new tires wear.

Battery service on hybrids and electric vehicles

All hybrid and electric vehicles have a 12-volt electrical system, and most of them also have a 12-volt battery. The 12-volt system is used for all the standard automotive equipment like lights and wipers, and it also powers all the electronics and control systems, including the Powertrain Control Module.

All hybrids have a 12-volt electrical system to power the lights and accessories and the electronic controls. Most, like this Toyota Camry Hybrid, have a 12-volt battery in the trunk that should be tested at least once a year.

Even though almost all models (except most Hondas) use the high-voltage battery to start the engine, the car won’t even turn on if the 12-volt battery is dead. It’s imperative for this battery to be checked any time the vehicle is in for service. Since it doesn’t get stressed by the starter, the driver never hears the one clue that we all rely on to warn us of a worn-out 12-volt battery: slow engine cranking speed.

The only service needed for the high-voltage battery on a hybrid vehicle is to make sure the battery cooling system is working properly. Many models have a separate cooling fan for the battery pack, and some have an air filter on the fan duct that should be changed along with the cabin air filter. On several models the battery pack is cooled by the vehicle’s air conditioner, which means the A/C might run even if the driver has not turned it on. It’s important to make sure the evaporator drain tube is not clogged.

Safety considerations for hybrids and electric vehicles

Although normal service work on a hybrid or electric vehicle can be done without disturbing its high-voltage system, that system carries enough voltage to cause fatal injury. If the car

Some high-voltage battery packs are air-cooled, while others are cooled by the vehicle’s air conditioning system. The battery on this Ford Escape has its own A/C evaporator. Most have an air filter that should be changed when changing the cabin air filter.

is completely turned off, such injury is extremely unlikely, but disabling the system is usually required for insurance coverage (not to mention peace of mind), and it is exceptionally simple to do.

There is a plug or switch on or near the battery pack itself that completely disconnects the high-voltage battery from the entire high-voltage circuit without disabling the 12-volt system. Honda Motor Co. Ltd. uses a simple on-off switch that looks just like a household circuit breaker. Most other manufacturers use a plug that you simply unplug or actually remove from the battery pack.

One note of caution: When the disconnect plug is removed, it can easily be lost. Most techs put it on the dashboard so it can be seen through the windshield. That way everyone can see that the high-voltage system has been disabled and no one will try to drive the car with the plug removed.

Finding the location of the disconnect plug can be a challenge. They’re commonly in the trunk or behind the rear seatback, but they can be anywhere on the vehicle. If you can’t find information on where and how to disconnect the high-voltage battery in your service information system, search the car manufacturer’s website for a section called “First Responder Guide.”

Insurance and safety regulations require the use of lineman’s gloves when removing or installing the service disconnect plug. These are rubber gloves with rolled cuffs that are Class O and rated to 1,000 volts. They should be kept in a bag that protects them from sunlight and damage, and while they