By Craig Van Batenburg, AAM
Craig Van Batenburg pictured with his Insight, the first one in Massachusetts. |
The Honda Insight and Toyota Prius - both hybrids - are often compared, although they are quite different.
In this competitive world I guess we have no other choice, as they are the only two hybrids on the market. The Insight first went on sale in December 1999 and the Prius followed in the summer of 2000.
The Honda Civic four-door hybrid sedan is due out this summer and Ford will be putting a Volvo-designed hybrid drivetrain into its Escape SUV soon.
Read on to see what you will need in the near future to service these half-and-half vehicles.
As of this writing, the Asian aftermarket Vetronix Mastertech supports the Insight but not the Prius. The manufacturers' shop manuals are not all that great with Honda's being better than Toyota's. Mitchell-on-Demand supports the Prius well and Alldata does a good job with the Insight, but you will need access to both to have information for both.
If your shop is well-equipped, your tools will be sufficient for now, as you most likely will only be doing regular preventive maintenance and minor repairs.
If a bulb burns out, don't panic - both cars run a normal 12-volt system for lights, radio and body controls. The safety warning is simple. (More will be written in the April issue of AutoInc. about safety.) Watch out for the orange cables. It takes over 60 volts to kill you. With 144-volt and 275-volt systems, these hybrids can be lethal if not treated with respect.
The concept of the Prius is much different than the Insight, and looks to be much more difficult to service. Since the Prius has been out less than two years, most cars are low mileage and under warranty. Some Insights are already off warranty. One Insight in southern California already has 125,000 miles on the odometer with the original nickel-metal hydride batteries still in good shape, as is everything else.
Toyota is worried about aftermarket shops touching its Prius so Toyota offers free maintenance for the first three years or 36,000 miles, but some Prius owners may still bring their cars to your shop anyway.
The Prius is cheap to rent at Toyota dealers, so if you want to get familiar with this hybrid, drop 50 bucks down for a day or two and drive one. It would be worth your time and money.
Some noteworthy environmental firsts are on these cars that have nothing to do with the hybrid part. Honda has a special N0x absorption catalytic converter located just behind the three-way catalytic converter (TWC). Toyota has a hydrocarbon (HC) trap in the outer shell of its catalytic converter that re-burns stored HC after start-up.
The Toyota gas tank is greatly improved. It has an expandable rubber bladder to control HC evaporation. No air space in the tank, less HC in the air outside.
These cars are clean and frugal with gas. About 50 mpg for the Prius and well over that for the Insight. I am an Insight owner. My best mpg has been 84.3, but I average about 60 mpg.
Some Similarities
What is the same about the Insight and the Prius? Both use a gasoline engine with an electric motor to provide power. Both use Panasonic nickel-metal hydride batteries. Both use an idle stop feature that shuts off the internal combustion engine (ICE) at idle under most conditions. Both use gravity, braking and the ICE to charge the batteries while you drive. Neither of the cars can be plugged into a 110v socket to recharge, nor do they need to. Both cars are made in Japan. Both cars use powerful electric motors as starters. Both spin the ICE at about 1,000 rpm at start-up. Both cars have electric power steering. They both use a constantly variable transmission (CVT) to help control emissions by keeping the revs low and constant.
Some Differences
What are the major differences? The Insight uses low weight and aerodynamics to the fullest. The Insight has an all-aluminum body, while the Prius has a conventional steel body. The Honda uses one electric motor; the Toyota has two. Prius is more conventional, seats four and is more popular. Insight is a simple design as hybrids go. Prius can be driven slowly only with its electric motor. The Insight is sportier, faster and is a two-seater. The Insight comes with a 5-speed stick or CVT; the Prius is only available with a CVT.
The Honda Insight
Van Batenburg says the Honda Insight is very aerosynamic but adds, some just think it is “weird.” |
To look more closely at the Honda Insight, let's see what we need for a first visit into our service bay.
Most of what you do to a Civic you will be doing to an Insight. When a valve clearance adjustment is required, it is easy. All adjustments are screw-type and are done cold - the intake specification is 0.007"-0.009", exhaust, 0.008"-0.010". Use OEM parts or parts of very good quality. There is no timing belt to replace because the 1.0 triple uses a chain. The clutch is hydraulic. The Honda Insight requires exactness so get it right when you make adjustments.
If you need to do a compression test, follow this procedure: You need to turn off the 144-volt system so that the car is in “12-volt mode.” It will then use the conventional starter, with a slower cranking speed. To do this, you must remove the rear deck carpet, then remove a small aluminum access panel - the only one with two bolts - in the center of the top aluminum plate. Then, remove the red switch cover and turn the system off. Wait 5 minutes and the car will be safe to work on if you read less than 12 volts at the orange cables.
Use a special tip on your tester leads that keep your fingers away from the high voltage. Don't forget that even when you disconnect the batteries and drain down the high voltage capacitors, the battery back always has high voltage in it.
Note: you have disconnected the alternator when you flipped the switch, so if you drive very far you may be walking back. You are now running a total loss system on a very small 12-volt battery. The 12-volt battery is located under the hood where you would expect to see it. Use the 12-volt mode for compression tests or any time you want to have the engine crank at low rpm.
The Insight has a conventional starter and small 12-volt battery as a backup in case the integrated motor assist (IMA) system fails or the 144-volt battery pack goes dead. The Insight can be jump-started but not push-started.
To keep your customers happy, be sure to adjust the high-pressure tires to their correct pressure: 38-PSI front, 35-PSI rear. Some owners raise the pressure higher for better fuel economy. Honda uses stick-on weights to balance tires, as all wheels are alloy.
A special Honda oil - “0/20” - and a special Insight oil filter will require 2.5 quarts at oil change time. Honda requires a special standard transmission fluid - MTF - and the 5-speed transmission has a 1.6-quart capacity. The CVT also requires a trip to the Honda dealership for fluids.
All-aluminum bodies require special bolts with a coating. Be sure the coating is still present if you are going to reuse the bolts.
As mentioned earlier, the Vetronix Mastertech with Honda aftermarket software will give you IMA codes and functions. The DLC is located right of the center console near the heater core. No cover; just look hard. Honda uses its lean air/fuel (LAF) sensor. It has been around a while and has five wires. Use NGK spark plugs only, ILZFR5A-11, iridium tipped. There are four standard plugs; check cylinder head for mark stamped onto head, either A-B-C-D, near spark plug hole. Make sure you install the proper plug per hole as the tip of the plug is indexed. Spark plugs have an A-B-C-D stamped on the top of each plug. Honda says “100K life” for plugs. We will see! Gap them at 0.40", but be careful because iridium is extremely soft.
More specs: Timing set at Red mark 12 deg. BTDC, +/- 2 deg. Firing order is 1-3-2. Compression test should yield no less than 130 psi. New for Honda: quick connectors on fuel pump lines (somewhat Ford-like). No special tools required. Fuel pump pressure: 40-47 psi. Fuel filter in tank (along with the pump). A/C capacity: 17.6-19.4 oz. Cooling system capacity: 2-3 quarts.
Electric power steering is simple. Honda uses a 12-volt system off its S2000 sports car. Scan tool data will give trouble codes through the DLC - again, with Vetronix Mastertech for now. Current ramping will help diagnose EPS problems. ABS scan tool. Again, you guessed it, Mastertech.
I suggest you do more preventive maintenance for the Insight than Honda recommends in the Honda manual. Remove the spark plugs at 60,000 and lube the threads, replace the thermostat every 60,000, service the calipers (aluminum) once a year in an area with road salt and/or humidity. Check and readjust valve clearance every 30,000. Caution here: Honda Insight uses a speed density F.I. system to calculate airflow so tight valves will cause a rich mixture. When the IMA system is a problem, more training and information should be available then. The IMA has its own trouble light on the dash.
The Toyota Prius
The Toyota Prius has four doors, a trunk and an automatic transmission, making it a great little family car. |
Now for the Prius: This car is a big seller compared to the Insight. They both cost about $20,000 but the Toyota has four doors, a trunk and an automatic transmission. It is a great little family car.
If you are familiar with Toyotas, then working on a Prius will not be a large leap. To get the cranking speed down to 300 rpm from the usual 1,000 rpm requires a scan tool and a bidirectional control. Once again, with almost 275 volts stored in the trunk, watch out for those orange cables. You can depower the cables by getting into the trunk and removing the trunk lining at the left rear by the seat back. Find the service plug (it is U-shaped) and remove it by folding a small handle down and pulling it out. Wait five minutes and the high voltage system should be off. Test any cables with a voltmeter before handling them to be sure you have 12 volts or less, not 275 volts! Fluke now has a tester on the market for high-voltage hybrid cars.
A 12-volt battery is stored away in the trunk, on the left side under a cover. It provides the power for everything except the high-voltage electric motors. If the car seems dead, charge the 12-volt battery (or jump-start it), then drive the car until the computers relearn. The digital dash needs time to re-record the level of the nickel metal-hydride batteries. This procedure is the same for the Insight. If the main high-voltage battery goes dead, you cannot restart the car with a jump. There is no backup starter, only a large electric motor that requires 275 volts. It looks like a “tow to dealer” at this time. When I asked Toyota representatives what they would do in this case, their answer was, “Our Prius high-voltage battery never goes dead.” OK, guess we will have to see about that later on.
The data link connector (DLC) is located at the left of the steering column and is easy to find. These cars are OBD-II compliant, but a hybrid problem is considered an emission failure. In states that require an OBD-II check for inspection, both power sources - the ICE and electric drivetrain - must be working properly.
Toyota's Prius uses coil over plug with a gap of 0.40". Oil is nothing special; use 5/30 and the oil filter is a standard Toyota part number. Oil capacity is 4.0 quarts. Using a timing chain, tuneups are easy.
Toyota installed drive-by-wire, so at the top of the accelerator pedal is a pedal position sensor (PPS). The power control module (PCM) keeps track of the revs but more importantly, the exhaust emissions are easier to control when the throttle is not snapped open and closed as some drivers may do. The drive-by-wire also aids in traction control.
The Prius uses similar quick disconnects at fuel lines, as does the Insight. Of course, electric power steering is used. Valve adjustment is typical Toyota: shims that are replaced when needed (they are usually OK for 200,000 miles). Specs for a cold engine are intake valves at 0.006" to 0.010" and exhaust clearance, 0.010" to 0.014". Spark plugs are ND SK16R11, gapped at 0.40". The CVT transmission uses ATF Type T-IV. Capacity is 5 quarts.
Toyota calls its system Toyota Hybrid Control (THC). The inverter gets very hot so it has its own cooling system, complete with reservoir tank, hoses, bleeders and radiator. The inverter sits on top of the transaxle and has a cover that says "Toyota Hybrid" on it. This has the high voltage going to it.
Tires are high pressure. Set the pressure at the front to 35 psi; the rear to 33 psi. The A/C system capacity is 17.64 oz. -/+ 1.76 oz.
Don't be afraid of these cars; just get acquainted. If you are weak on electrical systems, then get back to school. These hybrids are more like conventional cars than you might think - they just have extra computers, more sensors, more wires, more batteries and bigger electric motors. And the Honda has more aluminum. Even with all that, they still have four wheels and some of your customers will be buying them and bringing them to you for service and repairs. Just be careful. Up to now the cars we worked on were electrically tame. Not anymore.
If you want more information, go to my Web site - www.auto-careers.org. You will find more to read and links to some great hybrid sites.
