Hybrids are raising the green bar

Hybrids are raising the green bar

As gasoline prices head back above the $3 a gallon mark, so does the public’s interest in fuel-efficient vehicles such a hybrids. Toyota’s third generation Prius (2010 model year) raises the green bar even higher with its latest refinements.

The purpose-built Prius now gets 51 mpg city and 48 mpg highway (compared to 48/45 City/Highway for last year’s model); yet the engine is larger and more powerful (1.8L and 134 horsepower). The 2004-2009 models used a 1.5L engine.

So how does Toyota get better mileage with a larger engine? By reducing the engine’s RPMs 15 percent at cruising speed, and by using an electrically driven A/C compressor (which requires a special ND11 non-conductive oil), water pump and power steering. The new model also has an extremely low coefficient of drag of 0.25.

Something else that’s new on the 2010 Prius is an optional solar-powered ventilation system. The roof-mounted solar panel generates electricity to blow hot air out of the passenger compartment if the interior gets hotter than 68 degrees when the car is parked in direct sunlight. The solar panels are not used to recharge the battery because their output is not great enough (it would take 72 hours of direct Arizona sunlight to do that!). But who’s to say that future models might not use solar panels for supplemental recharging?

Last year, the Prius was the 13th best-selling vehicle in the U.S. So as time goes on, we will certainly see a growing demand for aftermarket maintenance and repair parts for the Prius as well as many other new hybrid models. The number of hybrids (all makes and models) now estimated to be on the road is about 1.5 million vehicles.

Though the Prius has been around since 2001, most independent repair shops have not seen many hybrids in their service bays yet. One reason is that hybrids are proving to be very reliable and trouble-free. The other is that the vehicle manufacturers have extended warranties on the hybrid powertrain components and battery. The factory hybrid powertrain and battery warranty on a Toyota Prius or Ford Escape (which uses a very similar hybrid drivetrain), is 8 years or 100,000 miles, or 10 years and 150,000 miles in California.

The actual design life of the Prius hybrid battery, according to Toyota, is 15 years and more than 200,000 miles. Prius models used in urban taxi fleets are reportedly racking up more than 300,000 miles on their hybrid battery systems with no failures. That says a lot about the impact of hybrid technology on the aftermarket parts and repair business.

Yet hybrids still have many components that are not “dealer only” parts and that are not covered by the hybrid warranty. The gasoline engines in these vehicles are still conventional engines that need normal maintenance and service. Regenerative braking extends the life of the brakes significantly, but the brakes don’t last forever. Same for the tires, struts, exhaust system, wiper blades, spark plugs, belts, hoses, filters, lights and many other parts on hybrids. At some point, you will be selling replacement parts to hybrid customers.

Contrary to what some people believe, there is virtually no danger of being shocked or electrocuted when performing normal maintenance, brake work or other basic repairs on a hybrid. These vehicles do have high-voltage batteries that range from 144 volts (first generation Honda Insight) up to 300 volts (Ford Escape), and may be stepped up to 500 to 600 volts inside the power inverter. Consequently, basic precautions must be followed when working on any high-voltage hybrid components. But most high-voltage components are well-insulated and color-coded orange (or blue in the case of 36-volt start/stop hybrid systems) to reduce the danger of coming into contact with high voltage.

You don’t have to wear rubber gloves when using a scan tool on a hybrid, or when doing any other non-hybrid maintenance or repairs. This includes oil and filter changes, replacing spark plugs or most other mechanical components. If a hybrid has electro-mechanical brakes, however, the brakes must be deactivated first by making sure the key is out of the vehicle and the “Ready” light is OFF.

In cases where repairs may be needed on any of the high-voltage hybrid components such as the engine power inverter, transmission or hybrid battery (but not the regular 12-volt battery), the hybrid battery must first be disconnected.

The procedure for isolating the hybrid battery varies depending on the vehicle, but typically involves flipping a switch on the hybrid battery pack or disconnecting a battery cable or fuse. On a first-generation Toyota Prius, the hybrid battery is disconnected by opening the trunk, removing the liner from the left front corner, and pulling straight back on a small orange handle to remove the battery connection plug.
Always refer to the vehicle manufacturer’s recommended disconnect procedure. This can usually be found in the vehicle owner’s manual. Also, don’t touch any high-voltage components for at least 10 minutes after disconnecting the battery. This gives the high-voltage capacitors in the hybrid control system time to discharge.
Protective rubber gloves capable of withstanding up to 1,000 volts should always be worn when doing a battery disconnect, as well as when handling a high-voltage hybrid battery or when working on any high-voltage components if the battery is still connected. Ordinary latex or neoprene shop gloves are not thick enough to provide adequate shock protection. Gloves must be Class 0 rated. Watch out for cheap imported gloves that may claim to meet these safety standards, but are too thin to provide adequate protection. Gloves should also be inspected before every use to make sure there are no cracks, tears or pin-holes. Replace any gloves that are damaged.

Hybrids incorporate a high-voltage leak detection circuit that will set a fault code and may even shut the vehicle down if any part of its high-voltage circuits short to the chassis of the vehicle. But this won’t protect an individual if he or she makes accidental contact with a live high-voltage component.

On 2001-2003 Prius, if you see the master warning light on and find a DTC P3009 code, watch out! That’s a code for a high-voltage leak from the hybrid battery to the vehicle chassis. Corrosion under a cover on the transmission vent can sometimes cause the high-voltage cables to short out. Another safety concern with hybrid vehicles is what happens after an accident. In most cases, the hybrid battery will be automatically disconnected and isolated if the air bag deploys. This protects the vehicle’s occupants as well as emergency responders from being shocked if people have to be cut out of a badly damaged car. But what if the air bag didn’t blow? In that case, the battery remains connected — and potentially dangerous. What’s more, if the key is still turned “on”, the vehicle could suddenly lurch forward if somebody bumps the gas pedal even if the engine is not running. Remember, hybrids such as a Prius or Ford Escape have a full electric mode that can move the vehicle with electric power alone when the engine is not running.

Various aftermarket tool suppliers have come out with insulated hand tools for use on hybrids. Such tools are not really necessary if the high-voltage hybrid battery has been disconnected. But they do offer added protection if someone is working near any high-voltage components or cables on a vehicle that is running or still has the battery connected.

One item that is needed for working on hybrids is a high-voltage digital voltmeter. The unit should be able to read up to 600 volts AC/DC, or up to 1,000 volts AC/DC for added range.

Depending on the make, model and year of the hybrid, the battery pack may be rated from 144 volts (Honda Insight or Civic) up to 330 volts (Ford Escape). The first generation Prius battery packs 273.6 volts, while the second and third generation batteries both produce 201.6 volts.

A special battery charger should not be needed for hybrid batteries because in theory, the battery is always recharged by the engine. The “auxiliary” 12-volt battery that operates the lights and other 12-volt accessories, however, can be charged with a conventional 12-volt battery charger. If the high-voltage battery goes down for some reason, it either means there is something wrong with the hybrid charging and control system, or the battery itself has failed.

However, if a hybrid vehicle is not driven very often, sits for weeks at a time in a garage, or has a problem that drains the battery or prevents the engine from running to recharge the battery, the hybrid battery may run down. If this happens, a special jumpstart procedure or charging procedure may be required to get the vehicle moving.

On a Prius, there is a special jumper connection under the power distribution center cover in the engine compartment. A 12-volt battery charger can be used to boost the regular 12-volt battery enough to start the engine (Toyota recommends using their special 12-volt charger instead of a conventional 12-volt battery charger). Once the engine is running, it should be left running for at least 30 minutes to recharge the hybrid battery. No attempt should be made to recharge or jump-start the high-voltage hybrid battery directly.

For diagnostic work, nothing beats an OEM factory scan tool. A factory scan tool with current software can access and display every data perimeter and run every self-test that is available on the vehicle. Unfortunately, that’s not always the case with many aftermarket scan tools, even the expensive professional models.

Basic DIY code readers and scan tools can be used to read and clear diagnostic codes, and to check OBD II monitor status before an emissions test. But DIY scan tools do not have bidirectional capability and cannot access the onboard self-tests for advanced diagnostic work.

If someone is working on a 2004 Prius and their scan tool is not communicating properly with the vehicle computer, the PCM may need to be reprogrammed. Toyota issued a recall on approximately 23,800 cars to reflash the computer to correct a programming error.

Another essential “tool” for servicing and diagnosing hybrids today is information. This includes diagnostic information, diagnostic codes and charts, technical service bulletins, service and repair procedures, and wiring diagrams. The best place to find this kind of information is on the vehicle manufacturer’s own technical Web site. Toyota’s Web site is techinfo.toyota.com. Honda’s Web site is www.serviceexpress.honda.com. A complete listing of OEM technical Web sites can be found at www.nastf.org.

Most of the OEM technical Web sites require users to pay an access fee that ranges from $20 to $30 for a “short term”(1- to 3-day) subscription. Longer monthly and even yearly subscriptions are also available for heavy users, but can be rather pricey ($200 to $300 a month, or up to $1,500 a year or more depending on the auto manufacturer).

A less expensive alternative is to subscribe to an aftermarket information service such as ALLDATA, ChiltonPRO or Mitchell. The advantage with these services is that one subscription fee covers all makes and models for the professional user. DIY subscriptions cover only a single make, model and year, but cost as little as $26 a year.
Technical service bulletins are often issued for faults that affect large number of vehicles, or for problems that fail to set codes (making diagnosis difficult).

Here are a couple that are out on the Prius:
* EG021-02 — 2001-2002 Prius, the MIL may come on and set a DTC P3125, which is an inverter malfunction code. The problem may be caused by a fault in the electronic control unit (ECU) or the hybrid inverter/converter assembly. The bulletin includes a detailed diagnostic chart that takes you through the step-by-step checks that are necessary to figure out what’s wrong. The fault often turns out to be a bad PCM.

* EG022-04 — 2001-2003 Prius. The MIL may come on and set a DTC P3130, and maybe also a DTC P3125, which are codes for a power problem or the Ready light not coming on. The fault may occur after the vehicle has been subjected to prolonged driving in heavy stop-and-go traffic, or when it has been driven at sustained high speeds during hot weather. The problem may be an overheated inverter/converter due to loss of coolant or coolant not circulating properly in the inverter/converter cooling system. The bulletin covers how to drain, refill and bleed the cooling system, and the replacement of the inverter/converter assembly.

* PG002-06 — This bulletin covers precautions for removing or installing the inverter/converter assembly on 2001-06 Prius, and 2006 Highlander and 2007 Camry hybrids. Basically, it covers the battery disconnect procedure, and how to service the components in the inverter/converter cooling system.

* Recall 06V266000 — A recall of 2001-2002 Prius models for the free replacement of a possible defective crankshaft position sensor that could cause the engine to stall and not restart.

Something else that cannot be overlooked is the need for hybrid training at all levels of distribution in the aftermarket, from warehouse distributors to parts professionals to technicians and even do-it-yourselfers. Hybrid components are very complex and require a thorough understanding of the entire system and how it all works. Hybrid training is available from a variety of sources, including the NAPA Institute of Automotive Technology, Denso, and independent trainers such as Craig Van Batenburg (www.auto-careers.org or (800) 939-7909) and Jack Rosebro (email [email protected] or (310) 801-7818).

You May Also Like

MAF and MAP Sensors

These small-but-mighty components play an outsized role in keeping fuel-injected engines running smoothly.

MAF and MAP Sensors

While it might not sound like it to the untrained ear, the orchestration of components to achieve the ideal combustion cycle is nothing short of a symphony.

For fuel-injected engines, two important instruments in this precise arrangement are the mass airflow (MAF) sensor and the manifold absolute-pressure (MAP) sensor.

Electronic Parking Brakes

Safety, convenience and holding power – what’s not to love?

Electronic Parking Brake
Driveshaft Dynamics

Don’t let the terminology trip you up.

Serpentine Belts Have a Strong Supporting Cast

Tensioners, balancers and pulleys are working behind the scenes to maintain harmony under the hood.

Tensioners and Pulleys
Artificial Intelligence in the Automotive Aftermarket

The applications for AI are endless, but hurdles still remain.

AI Aftermarket

Other Posts

Fundamentals of Automotive Electrical Systems

This system is called upon every day to do more and more.

Automotive Electrical
Interpreting Dashboard Warning Lights

Navigating the neon jungle isn’t as easy as it used to be.

Dashboard Diagnostics
Stopping Power: Brake Master Cylinders

The brake master cylinder is the hydraulic hero behind every safe stop.

Brake Master Cylinder
Active vs. Passive Wheel-Speed Sensors

Both have the same job, but they differ in how they do it.