Info - 2007 Saturn Aura Green Line Hybrid New Model Features and Service Guide

The purpose of this bulletin is to introduce new features of the 2007 Saturn Aura Green Line hybrid vehicle and describe the actions that your Service Department will need to take to ensure that you are able to fully service this exciting new model.

General Precautions

The Aura Green Line hybrid system uses a 36-volt battery pack located in the trunk area behind the rear seat, a belt-driven starter-generator and control electronics located on the driver’s side of the engine bay at the core support.

Caution: To help avoid personal injury, always ensure the ignition switch is in the OFF position and the ignition key has been removed prior to working on any 36V components. After the key has been removed, disconnect the negative 12V battery cable and then open the generator battery disconnect control module cover. After waiting for at least 5 minutes, measure the voltage potential using a DMM between the following:

All of the 36-volt circuits are identified with blue wiring conduit. The 36-volt system uses the vehicle chassis as a ground circuit in parallel with the conventional 12-volt system. Care should be taken when working near this 36-volt wiring and associated components. Refer to Hybrid Battery Service Disconnect/Connect in SI for 36-volt disconnect procedures.

First Responder Information

First responder information for all GM Hybrid products can be found on the Internet by following the Emergency Personnel Information link from http://gmstc.com. This central location will be maintained and provide the most current critical information for the first responder public. First responder information is available in English language only at this time.

U.S. Retailers: To enroll in and/or complete the following training, refer to http://www.gmtraining.com.

Canadian Retailers: Refer to latest training availability in the GM Canada Product Service Training Course Catalogue located on GM infoNET under Service & Body Training.

Performing a quality pre-delivery inspection (PDI) is one of the most important functions the Retailer can do for the customer. Most customers consider the condition of their new vehicle during delivery as a direct reflection of the Retailer and your service department. A quality PDI is essential to improving a customer's perception of your facility and increasing his/her satisfaction with their new vehicle.

U.S. Retailers: The Aura Green Line-specific PDI forms are available via DealerWorld. These forms contain the same generic PDI steps as before, but also include a section for Special Inspection Items. This section is updated monthly and contains special items to look for during the PDI process.

Canadian Retailers: Pre-Delivery Inspection forms are available for download from the GM infoNET.

Please remove the protective covering from the Hybrid logo on the battery cover during the underhood inspection of the PDI process.

Customer Education

It is imperative that the customer be well informed about the unique features and operational characteristics of their Aura hybrid. For the sales team to be fully prepared, they should thoroughly review this New Model Features and Service Guide and use the Getting to Know Your Vehicle (GTK) guide (U.S. Only) as an outline when presenting a hybrid vehicle to a prospect.

Additionally, service and parts leadership, service writers and technicians should familiarize themselves with these materials to avoid attempting repair of normal operating characteristics.

Getting to Know Your Vehicle Guide (U.S. Only)

A copy of the GTK can be found on the GM training web site (http://www.gmtraining.com) by following the links for Product Training > Product Information > GTK - Getting To Know Your Vehicle Brochures > Saturn. This guide is also included with the glove box materials within each vehicle.

In general, the hybrid system uses battery power to assist the gasoline engine in accelerating and driving the vehicle. This is referred to as the hybrid assist mode of operation. The majority of the energy depleted from the battery is replenished during coasting and braking, using the moving vehicle to charge the battery. This mode is called regenerative braking. Additional charging can occur while driving, using power from the gasoline engine.

This cycle of the battery power assisting in the acceleration of the vehicle and being recharged during deceleration and braking results in a significant improvement in fuel economy.

In the hybrid assist mode of operation, the 2.4L LAT powertrain can provide a significant boost to performance. This additional performance will not typically generate any form of owner concern or negative comment.

However, during the coast-down and regenerative braking, the generator creates drag on the vehicle and feels more like a manual transmission (with engine braking) than a typical automatic transmission vehicle. This feeling of drag may result in owner comments or concerns developing. The sales team should feature this characteristic to prospects and owners upon delivery - stressing that this feeling is normal and desirable as the hybrid system recaptures energy from the moving vehicle. Additionally, during many of these coasting and regenerative braking events the engine is not being fueled at all, providing further fuel economy. This period of operation without fuel is called "deceleration fuel cut off."

As the vehicle slows and approaches a stop, fuel is returned to the engine and the regeneration is reduced. These actions reduce the drag on the vehicle, which then coasts more freely. This elimination of drag may be commented upon until the owner is accustomed to this normal operation.

Additional fuel economy is achieved through the "Auto-Stop" when the vehicle comes to a complete stop. In the "Auto-Stop" mode the engine completely stops and, therefore, uses no fuel. As the operator releases the brake, the hybrid system will restart the engine and the cycle repeats.

There are a number of system requirements that must be satisfied for the engine to be commanded to "Auto-Stop." These requirements include:

After the vehicle goes into an "Auto-Stop," it will only remain in "Auto-Stop" for a maximum of 2 minutes. Additionally, if any of the required conditions change, the engine may re-start at any point in this 2 minute cycle, like:

Many of the conditions that allow, or shorten, an "Auto-Stop" are not visible or controllable by the operator. In general, an occasionally skipped "Auto-Stop" should be considered normal. If a system malfunction is the cause for loss of "Auto-Stop," a malfunction code (DTC) will be set.

Refer to the How to Maximize Fuel Economy section below for tips on increasing the occurrence and length of the "Auto-Stop" mode.

Although the hybrid Aura is rated at 28 mpg/city and 35 mph/highway U.S. (8.5 L/100 km city and ? 6.2 L/100 km highway in Canada), fuel economy can vary greatly depending upon how the vehicle is driven. The measurement of fuel economy during vehicle break-in will typically generate lower numbers. Measured fuel economy will tend to stabilize after the first 1000 miles (1600 km). After this initial period, there are several techniques that can help maximize fuel economy.

Use of "ECO" light

The green "ECO," or economy, telltale was added to the cluster to inform the operator that they are achieving, or exceeding, the rated fuel economy for the given driving speed. Using this light as a guide will improve the fuel economy experience.

This light can be disabled using the DIC buttons on the steering wheel. With the engine off and the key turned to accessory, set the DIC to the outside air temperature and odometer mode. Press and hold the reset button for several seconds. The light will come on solid and then flash several times and turn off to indicate that it is disabled. Repeat the procedure to enable the light.

Vehicle Acceleration

A significant amount of fuel is used in vehicle acceleration. To improve economy, accelerate smoothly and gradually with the lowest reasonable throttle level. As you approach your desired speed, reduce throttle until the green "ECO" light illuminates. Attempt to keep the "ECO" light illuminated whenever driving at a constant speed. Allowing a drop in speed when climbing a grade will save fuel over increasing the throttle to maintain a given speed.

Coasting and Braking

During many coast conditions, the hybrid vehicle achieves its highest fuel economy as engine fuel flow can be shut off and regenerative braking charges the batteries. In contrast, braking converts the energy of the moving vehicle into heat - which cannot be recovered. To maximize economy, rather than "driving" with the throttle applied up to traffic, a light or stop sign, the operator should begin coasting sooner allowing regenerative braking to slow the vehicle more gradually. In short, begin coasting sooner, and brake less.

A/C Operation

Use the "AUTO" feature on both the fan setting and the mode setting. Also select a temperature setting that is higher in warm weather and lower in cooler weather.

If the "AUTO" feature is not utilized, minimizing the application of the A/C compressor will also improve economy. If for passenger comfort A/C is desired, use the "Hybrid Air Conditioning " mode identified by the button with the green H next to the snow flake.

To improve passenger comfort during "Auto-Stop" turn on air recirculation on the HVAC control panel. This will not only improve the comfort in the vehicle, but will tend to allow "Auto-Stop" to last longer as the evaporator temperature will rise at a slower rate. Using recirculation will improve economy over use of the "Normal A/C" mode (single snowflake) with similar comfort.

Air delivery mode is also important when trying to minimize A/C compressor operation. As shown in the following table, setting the air delivery to the windshield (Defrost) mode will force the A/C compressor ON, and disable "Auto-Stop" regardless of the operator-selected A/C mode. If possible, it is suggested to dial the air delivery one detent counter-clockwise, or ‘one click back’, from defrost to at least allow "Auto-Stop."

This table also shows that when the A/C mode is OFF (no LED), the A/C compressor will still be commanded ON anytime the air delivery is to the floor or rotated clockwise from "floor." This is to minimize window fogging. For an owner who wishes to maximize their fuel economy, selecting "one click back," or more, from "floor" will disable the compressor.

The purpose of this section is to familiarize you with the technical aspects of the Aura hybrid vehicle and introduce the major hybrid components. The following information will only define the differences between the base Aura and the Aura hybrid vehicle.

The primary components in the hybrid include:

The engine included in the 2007 Aura Green Line hybrid is a 2.4L 4-cylinder (RPO LAT) rated at 164 hp at 6400 rpm. This engine features Variable Valve Timing and coil on plug ignition - similar to the 2.4L used in the 2006 and 2007 ION.

This engine is equipped with a new accessory drive system with a 7-rib, high strength belt and a unique dual belt tensioner that allows the generator to drive the crankshaft in "Auto-Start" and assist modes, and allow the engine crankshaft to drive the generator in normal electrical generation and re-generation modes.

Smart Start

Unique to the hybrid Aura is an ECM-controlled "Smart Start" system. If the operator lightly "bumps" the ignition to the "start" position and returns to run, the starter will continue to run until the engine starts or a maximum crank time is reached.

Auxiliary Coolant Pumps

Two auxiliary coolant pumps are included in the design of the hybrid. One is used anytime the engine is running to circulate coolant through the starter/generator control module. The other is used to provide circulation of coolant through the heater core and will only be run while in "Auto-Stop" depending upon the outside air temperature.

The transmission is a modified 4T45E (RPO ME7) transmission that includes an external auxiliary pump to maintain transmission line pressure, and therefore clutch activation when the vehicle is in ‘Auto-Stop’ mode. This transmission has other hybrid-specific content including a modified channel plate, spacer plate and valve body. Care when ordering service parts is required to reference the correct transmission RPO.

The Aura Hybrid vehicle comes standard with ESC (Electronic Stability Control) as the base brake system.

The brake system has been modified for the hybrid vehicle. These modifications include the addition of a brake booster vacuum sensor, a brake hydraulic pressure sensor.

The brake booster vacuum sensor is mounted to the brake booster and provides booster vacuum status to the ECM. This input is used to either inhibit "auto-stop" or force an "auto-start" if the vacuum level is too low.

The brake hydraulic pressure sensor is an input to the ECM that is used to sense the pending release of the brakes. This is used by the ECM to command an "auto start" as the operator releases the brake. The ECM must "learn" the zero-pressure value when the ECM is either reprogrammed or replaced.

The hybrid vehicle is equipped with special, low rolling resistance Uniroyal Tiger Paw Touring SR P215//60R16 M+S tires. These tires are available through Saturn Service Parts (in Canada, the PDC).

The IP cluster has a modified tachometer that includes an indication of "Auto-Stop" and "Off" to communicate these modes to the customer. A "Charge/Assist" gage is located on the right side of the cluster to communicate if the hybrid system is charging the battery, or if the hybrid system is assisting the engine in propelling the vehicle.

In some cases, an owner may wish to not have the "ECO" light illuminate. To disable the "ECO" light use the DIC buttons on the steering wheel. With the engine off and the key turned to accessory, set the DIC to the outside air temperature and odometer mode. Press and hold the reset button for several seconds. The light will come on solid and then flash several times and turn off to indicate that it is disabled. Repeat the procedure to enable the light. Turning the ECO light off only affects the operation of the green "ECO" telltale.

Additional DIC specific messages for the Aura hybrid are:

The hybrid HVAC control panel is similar to the HVAC control panel in the Aura XR (C68). The unique feature with the Aura Hybrid HVAC control panel is the addition of an "Hybrid A/C" mode. The Hybrid A/C button features a green H next to a snowflake.

In the "Hybrid A/C" mode the operator is allowing the "Auto-Stop" hybrid function when the vehicle is at rest in drive. The "Normal A/C" mode is selected with single snowflake (left most button). In "Normal A/C," the operator requests no "Auto-Stop" mode.

The operator-requested A/C mode may be overridden by the HVAC system depending upon air delivery selection. When the Defrost air delivery mode is selected, "Normal A/C" will be commanded, disabling "Auto-Stop" regardless of the operator-selected A/C mode. Additionally, the A/C compressor will operate if the air delivery is selected anywhere from floor to the first detent back from defrost. This compressor operation is commanded in order to dehumidify the incoming air to avoid window fogging even when the A/C LED is not illuminated.

To maximize fuel economy the use of the "AUTO" selections for both Fan Speed and Air Delivery mode should be selected.

The hybrid Aura should not be used to tow a trailer. It can be recreationally towed with all four wheels on the ground. For complete information on towing, refer to the latest copy of "Trailer, Recreational and Disabled Vehicle Towing Information," Corporate Bulletin Number 03-00-89-033E.

If the Hybrid vehicle is to be stored for a period greater than 30 days, the 12-volt battery negative cable should be disconnected to protect both batteries from discharge.

The hybrid battery pack is designed to be charged by the hybrid system only. The hybrid system monitors the voltage and temperature of individual battery cells and controls the charging rate to optimize the life of the batteries. There is no provision at this time for "off-board" charging of the battery pack and such charging should not be attempted. In the event of a significant battery discharge, it may be necessary to replace the complete battery pack.

Menu Prompts (U.S. TAC Only)

The Technical Assistance Center has modified the telephone prompts to target hybrid Aura calls to a specialized group. After calling TAC at 877-446-8227, the caller will press 1 to "Speak to a TAC Consultant," press 2 for a "New Case," press 2 to NOT route to an Action Center, and continue to follow the prompts for "Hybrid." The last prompt will route by "Propulsion System" or "All Other Areas."

* Canadian Retailers: Calls relating to the Hybrid Aura should be directed to the Saturn/Saab group within GM Canada TAC.

Restricted Parts

Refer to Corporate Bulletin Number 07-06-01-005 for additional information regarding 2007 Saturn Aura Green Line hybrid restricted parts.

Many of the hybrid-specific electrical/electronic parts will be restricted for the six months, not allowing parts departments to order these parts. To obtain a restricted part, the service department will need to contact Technical Assistance who will assist in the diagnosis, document the issue and submit the parts order to Saturn Service Parts on behalf of the retailer.

Caution: To help avoid personal injury, always ensure the ignition switch is in the OFF position and the ignition key has been removed prior to working on any 36V components. After the key has been removed, disconnect the negative 12V battery cable and then open the generator battery disconnect control module cover. After waiting for at least 5 minutes, measure the voltage potential using a DMM between the following:

For all the parts that are included in the following restricted list, it is important that these parts are not disassembled more than is necessary to remove them from the vehicle or more than the supplied replacement part. Further disassembly in the field may result in disturbing the assembly, therefore reducing the benefit of the parts restriction.

The hybrid radios, IP clusters and DVD displays will be serviced through the Electronic Service Centers (ESC). Refer to the following bulletins and/or subsequent updates for ESC program part processing.

Hybrid parts will be returned through the Warranty Parts Center (WPC) by request using the Saturn Failed Parts Return System. For additional information on the parts return process, reference the latest revision of Corporate Bulletin Number 05-00-89-042B - "Warranty Parts Center/Saturn Parts Return Program (U.S. Only)." Canadian Retailers should refer to Service Bulletin 99-00-89-019C for all Warranty Parts Center returns.

Caution: To help avoid personal injury, always ensure the ignition switch is in the OFF position and the ignition key has been removed prior to working on any 36V components. After the key has been removed, disconnect the negative 12V battery cable and then open the generator battery disconnect control module cover. After waiting for at least 5 minutes, measure the voltage potential using a DMM between the following:

Battery Pack Special Handling Requirements

The battery pack should NOT be disassembled more than is necessary to remove it from the vehicle. Further disassembly in the field may unnecessarily subject the technician to potential personal injury and may result in disturbing the assembly and reduce the benefit of the parts restriction.

For return shipment of the battery pack (Hybrid Battery Assembly - P/N 15940523), additional special handling is required.

1. The "NONSPILLABLE" Label included with replacement battery pack must be installed on the failed part prior to return shipment to the Warranty Parts Center (WPC).
2. Protect the battery terminals from short circuit during shipping. Using a heavy cloth tape, cover the battery module negative and positive terminals, and cover the top portion of the exposed "Battery Disconnect Control Module." DO NOT TAPE OVER THE BATTERY DISCONNECT PLUNGER.
3. Package the part to be returned in the same container that was used that was used to deliver the replacement part. This container has specific labeling for a Class 8 hazardous materials that are exempt from a hazardous material classification for the purposes of transportation.

The "Compressor, Hydraulic Belt Tensioner," tool number EN48079, is the only required unique special tool.

As with any new vehicle, or vehicle technology, prompt detailed feedback on owner concerns and/or vehicle conditions in the field is of great value to the manufacturer.

U.S. Retailers: To provide Voice Mail reports on the product the retailer should reference the latest version of Corporate Bulletin Number 02-00-89-002E - Information for Dealers on How to Submit a Field Product Report (FPR).

Canadian Retailers: Submit Product Information Reports (PIRs) using the electronic PIR form located on the GMinfoNET. Refer to the latest version of Corporate Bulletin Number 02-00-89-002F - Information for Dealers on How to Submit a Field Product Report (FPR).

In the event that a vehicle reaches the end of useful life and is due to be dismantled, information on the recycling of the hybrid battery pack can be found at http://www.recyclemybattery.com.

Important: Canadian Retailers: The above website link will direct you to a list of Commercial Battery Recyclers. GM is not recommending these recyclers nor is it an exhaustive list of available recyclers. Two such battery recyclers listed are Inmetco (www.inmetco.com) and Kinsbursky/Toxco (www.kingsbursky.com). These U.S.-based companies specialize in the recycling of batteries, including the Nickel Metal Hybride (NiMH) type used in the Aura battery pack. Additional information an be obtained by contacting these companies directly via their respective websites. You are responsible for complying with all federal, provincial, and local laws and regulations relating to the shipment of the hybrid battery back. Please note that provincial and/or local laws can be more stringent than federal regulations, so be sure to check all three.