May 2008 Archives

G8 FEATURES

Pontiac's new flagship sport sedan (fig. 1) is based on a new global rear-wheel drive architecture, and is available in two levels, the G8 with V-6 engine and the G8 GT with V-8 engine.

Powertrains

Two levels of performance are offered.

The 3.6L DOHC VVT V6 (LY7) (fig. 2) on the G8 model is teamed with a 5-speed automatic transmission that offers Driver Shift Control (DSC).

And the 6.0L OHC V8 with Active Fuel Management (L76) (fig. 3) on the G8 GT model is teamed with a 6-speed automatic transmission. This is the first application of AFM on a rear-drive sedan. The transmission offers DSC and two overdrive gears.

TIP: DSC allows the transmission to be shifted like a clutchless manual.

Wheels, Tires and Brakes

Depending on model and package combinations, both 18- and 19-inch aluminum wheels are offered, with either all-season or summer-only tires. Both models use 4-wheel vented disc brakes with an antilock brake system (ABS) and StabiliTrac. GT models are equipped with larger rotors.

TIP: The summer-only tires must be replaced for winter driving. Details are found in bulletin 04-03-10-013B

Keys

IMPORTANT: Keys are ordered through GM SPO with overnight service from FM-Reps.

Ignition/door lock keys feature either an attached remote fixed key or an attached compact flip key housing (fig. 4). An 8-bit code requires a new code adapter to enable keys to be cut from the key code using previously specified Silca key cutting equipment. A third key (no remote) is for the glove box lock.

TIP: See the October 2007 issue of TechLink for an in-depth explanation of the side-milling feature of these keys.

Fluids and Lubricants

Many of the fluids and lubricants specified for the G8 are new. Be sure the fluids and lubricants listed below are available in your dealership, and be sure that only correct fluids and lubricants are used. Damage may result from use of incorrect materials. A chart in New Models Features Bulletin 08-00-89-008 summarizes some of the most critical. Refer to SI and the Owner Manual for a complete list.

Battery

The G8 battery is located in the trunk. To prevent explosive gases from entering the passenger compartment, the battery is fitted with an external ventilation tube which carries gases to the outside of the passenger compartment. A replacement battery must incorporate the external ventilation feature which must be correctly fitted when the battery is installed.

TIP: If the replacement battery does not come with the ventilation tube, it is vital that the tube be removed from the old battery and securely fitted when the new battery is installed.

Do not disconnect the main vehicle battery or remove the OnStar fuse with the ignition key in any position other than OFF. Allow Retained Accessory Power (RAP) to time out, or disable by opening the driver's door before disconnecting power.

Disconnecting power to the OnStar module while the ignition is ON or with RAP activated may cause activation of the OnStar Back-Up Battery (BUB) system and will discharge and permanently damage the back-up battery.

Accessory Power Outlet

The Accessory Power Outlet is not powered all the time. The APO is tied to the retained accessory power, so the APO will power off when retained accessory is off.

- Thanks to Chris Graham and Fred Tebbets



PRE-DELIVERY INSPECTION

Bulletin 08-00-89-008 explains the G8 Pre-Delivery Inspection (PDI) in detail. Here are some highlights.

Delivery Condition

Vehicles are delivered with factory-installed protection materials on external surfaces and on interior components. To ensure that they can be easily removed, they should be removed within six months of the vehicle build date.

TIP: Shipping vehicles from GM Holden in Australia includes about two months of ocean transit and up to four weeks of rail and truck transit from the west coast port. So, the protective materials may have been on the vehicle three or more months by the time you receive the vehicle. Shipping materials should be removed within 90 days of when you receive the vehicle.

TIP: You can find the month and year of manufacture on a white label in the driver's door jamb area.

Exterior

Rapguard film for paint protection is applied to external horizontal painted surfaces to provide protection from ultraviolet light, fallout and chemical attack from bird droppings, etc.

Scotchcal, a heavier grade of adhesive film, is applied to front and rear fascia and provides protection against minor contact in transit.

Under normal circumstances, the Rapguard and Scotchcal films should easily peel away from the surfaces and leave no residue. Films may become brittle and difficult to remove if left on the painted surfaces for longer than six months from the date of manufacture.

Interior

The interior protection package consists of a seat cover on the driver's seat, plastic film on the driver's floor carpet and plastic protective tape on driver's door sill plate.

TIP: All interior protection film/tape must be removed no later than six months from the vehicle manufacture date.

PDI Tips

In addition to removing the protective materials, the following procedures and inspections are outlined in bulletin 08-00-89-008.

Brake disc protection covers are manufactured from a high-strength plastic material with vapor-emitting paper attached to the inner surface. They are designed to provide disc surface corrosion protection.

These covers can be removed by tearing them away from the brake disc area. There is no need to remove the wheels. Be sure that all protective material is fully removed.

TIP: There is no need to remove covers while the vehicle is in storage; however, effectiveness of the cover will progressively reduce as the cover ages.

Spring chocks are fitted between the front suspension coils to prevent excessive suspension travel during shipping. These must be removed before the vehicle is driven.

With the front of the vehicle raised and the wheels at full hang, remove the chocks by pulling them out by hand.

Tire inflation -- Tires are inflated to 60 psi (413 kPa) for flat spot prevention during transportation and storage. This is not suitable for normal driving. Ensure that this pressure is maintained while the car is in storage but deflate the tires to the specified pressure before delivery to the owner.

TIP: The tire pressure placard is located on the rear face of the left hand front door opening.

G8 GT models (all V-8s) are equipped with a tire inflator kit only. G8 models (all V-6s) have a space saver tire and jack equipment.

Battery transit isolator -- To minimize battery drain in transit, some circuits have been disabled by disconnection of a transit isolation connector located above the battery in the trunk.

Locate the blue connector in the battery compartment (fig. 5). Connect the two mating blue connectors to energize the radio, HVAC, supplemental instrument clusters in the IP center stack area, IP cluster and remote locking.

IMPORTANT: It is critical that the two parts of the connector are fully assembled. Push the connector until a click is heard, then tug to be sure it's seated. The connector connects only one way.

Immediately after the vehicle is received, check the battery open cell voltage. Battery voltage must not be allowed to drop below 12.3 volts during storage.

Other -- Numerous other checks and procedures are outlined in the bulletin. Be sure to perform all of them as directed. Print the G8 PDI worksheet from DealerWorld and review it for items specific to the G8.

If you have any product concerns with the vehicle, complete a Field Product Report. Review the information with your dealership Service Management Team before sending the communication.

- Thanks to Chris Graham and Fred Tebbets

In February, GMSPO released the long-awaited Service Information (SI) with a new look and robust new search engines. The following is a quick overview of its key changes and enhancements.

Browsing in SI

New to SI is the Navigation Build History (also known as the 'bread crumb trail'). The trail appears at the top of the screen as you travel through the service publication. Navigation Build History provides a quick reference so you can easily jump to previously viewed selections.

Searching in SI

The new and enhanced search engines allow much greater flexibility when searching for information in SI. Understanding how they work will make your searching quicker and more efficient. The keyword searches should never be used as a way to circumvent the diagnostic process.

There are two methods for searching -- Basic (the default) and Advanced. Under either method, you can search the full text (known as Document) or just the Titles. Document search is the default. The new search feature is available in all publications, including Service Manual/Bulletins, Owner Manuals, and Labor Time Guide.

The key difference between the two is that Basic treats each keyword individually, while Advanced treats multiple words as a phrase (requires two words or more).

Basic search performs a search on keywords -- up to five keywords can be used. If multiple keywords are entered, you can further define the search for 'any' or 'all' of the keywords. The words 'and/or' are not allowed in the search field.

TIP: The Basic search treats each keyword individually. If multiple words are entered, the program rearranges them in alphabetical order after the search begins.

For example, Throttle Position Sensor becomes Position Sensor Throttle. This produces entirely different results

TIP: Search results under the Basic method will find derivatives of the keywords entered. Example: Keyword Brake will find brakes, braking.

Unlike the old SI, partial words are not recognized as valid keywords. Example: Previously Sche would find schematics; this search method is no longer valid.

Advanced search searches on a phrase (two or more words). Searching for Throttle Position Sensor produces results that are an exact match, and in the order they are entered. Understanding what is considered a phrase is the key to understanding the Advanced search method.

TIP: A phrase of up to five words can be searched. Valid search characters include slash (/), period (.) and hyphen (-). Example: a/c, 5.7L.

Example: 5.7 is considered a phrase and not a keyword. Within the Basic search, 5.7 is treated as three keywords: 5, . , and 7.

For a more detailed explanation of the Basic and Advanced search features, select the Search Help link at the top right of the page.

All document lists are now displayed with alternating background shading and with larger line spacing. On the home page, there is a link to the user guide that includes helpful information regarding SI.

Category Search

After you select a Service Category, a Basic or Advanced search can be performed within the selected section or the entire manual.

Unit Repair and Specialty Publications

The SI application now offers Specialty Publications located with the Unit Repair Manuals. The Specialty Publications are not related to a specific year, make or model. The SI application offers the search feature for these publications as well.

- 2008 Performance Engines Manual

- 2008 Marine Engines Manual

- Thanks to Michael Raposa, Mike Rice and Lisa Scott

SDM Module

Before reprogramming or replacing the SDM module, be sure the condition is irreparable by known diagnostic procedures in SI. Replace the SDM only when DTC B1000 sets. Other faults can be addressed by reprogramming the module.

In the event SDM module has to be reprogrammed, use this procedure.

1. Key ON, engine OFF. Program the SDM using SPS.

2. Key OFF and then ON. Airbag Light SIR indicator should flash when reprogramming is successful and there are no DTCs.

3. Using a scan tool, perform setup SDM Primary Key in BCM special functions module setup.

4. Using a scan tool, perform Setup New SDM in special Functions in the SDM.

5. Key OFF and then ON. Verify no DTCs are present. If present, repair and then clear faults.

PPS Module

Due to the sensitive data and software operation, PPS modules can be reprogrammed only in special circumstances. However common faults can be fixed by diagnosing the condition and by module reset. Detailed procedures on how to repair PPS module conditions are available in SI.

In the event PPS has been replaced or SI instructs to reset (Rezero) the PPS module, use these steps.

1. Empty the front outboard passenger seat.

2. Verify that all SIR and PPS components, connectors, and connector positions assurances (CPAs) are properly connected.

3. Install a scan tool.

4. Turn on the ignition, with engine OFF.

5. With a scan tool, clear DTC B0081 4B if present. Perform a Passenger Presence Rezero or Preload procedure based on SI and scan tool instructions.

6. If the test fails, adjust the seat trim, massage the seat surface to ensure even pressure across the seat sensor pad. Repeat the Passenger Presence Rezero or Preload procedure.

IMPORTANT -- Service Programming System (SPS) maybe required on some vehicles to unlock PPS modules before Rezero or Preload procedure is done. SPS should be used when the PPS module locks upon unsuccessful attempts to rezero or preload.

- Thanks to Reuben Wanjala

Traditionally, diesel fuel has been refined from crude oil, and is referred to as petroleum-based (or petro) diesel. It is now possible to manufacture diesel fuel from biological (plant and animal) materials. This fuel is referred to as biodiesel. Biodiesel fuel is blended with petrodiesel fuel (typically 5% bio and 95% petro), and the result is referred to as a blended fuel. Because the characteristics of petroleum diesel and biodiesel fuels are different, questions arise about the use of biodiesel fuels in GM vehicles. Here are some typical questions and answers.

Owner manuals state that GM diesel engines can operate on up to 5% biodiesel fuel. Are all 5% biodiesels the same?

GM currently supports the use of up to 5% blend of biodiesel (B5) in all its diesel vehicles.

GM does not distinguish between the types of feedstocks (different vegetable oils and animal fats) used to make biodiesel. However, biodiesels are not all the same. Biodiesels made from different feedstock will have different cloud points (see below) and subsequently blends made from these feedstocks will have different cloud points. In addition, some variations in cloud point can be expected due to processing differences.

Inconsistent blend compositions might result based on blending methods (example splash blending) and temperature of blending (it is recommended that biodiesel be kept at least 10°F (6° C) above its cloud point during blending). Cloud point will increase with increasing amounts of biodiesel in blends.

When using 5% biodiesel, are there negative performance or durability considerations?

ASTM International (originally known as the American Society for Testing and Materials) is the organization which defines the desired quality of biodiesel for vehicular use in the US.

If the biodiesel meets the ASTM standard, there are no durability concerns at the 5% level. However, if the original biodiesel does not meet the ASTM specification, even with 5% there is potential for negative effects. For example, glycerin is a byproduct formed when vegetable oil is processed to make biodiesel. This is a potential contaminant. In addition, any unreacted vegetable oil is also a potential contaminant. Biodiesels high in glycerin and unreacted vegetable oil content (>0.24 mass %) can result in gelling at higher temperatures, causing filter plugging, and can also cause long term injector damage.

5% biodiesel can cause negative effects if the fuel in the tank deteriorates to form insoluble (plastic-like) constituents and corrosive products.

Biodiesel fuel has a higher tendency to foul and oxidize compared with petroleum diesel fuel. Performance at cold temperatures will be somewhat worse because biodiesel naturally has a higher cloud point than diesel fuel.

Could 5% biodiesel be a cause for premature filter plugging?

Yes, if biodiesel is out of spec for glycerin or when it oxidizes to form polymeric constituents. Biodiesel can act as a solvent, loosening sludge in the bottom of the tank that will cause the filter to plug.

How much does ambient temperature affect biodiesel's ability to flow in a suction-only fuel delivery system?

Ambient temperature affects the fuel's tendency to gel and its ability to flow. As the fuel is cooled, its ability to keep the wax dissolved decreases, and eventually, a temperature is reached when the wax precipitates from the fuel. The temperature when the fuel first becomes cloudy due to wax precipitation is called the cloud point. As the fuel is cooled further, more wax precipitates from the fuel. At about 10°F (6° C) below the cloud point, the fuel becomes so thick that it cannot flow. This temperature is called the pour point or gel point.

A 5% biodiesel will raise the cloud point of the fuel about 4 to 5 degrees F (2 to 3 degrees C). A 20% biodiesel will raise the cloud point 5 to 10 degrees F (3 to 6 degrees C). Because fuel passes through the fuel filter before it reaches the suction side of the pump, the expectation is that this type of system would be susceptible to filter plugging due to wax or precipitates.

Are there GM recommended additives that may reduce negatives of biodiesel?

No, at present GM does not recommend any additives. Diesel Fuel Conditioner (p/n 88861009 or p/n 88861038 in Canada) is meant for diesel fuel only. Its effectiveness in biodiesel blends is unknown.

What happens if the customer increases the percentage? 10-20% is apparently available on the street.

An increase in percentage will raise the cloud point of the fuel. It can also cause compatibility issues with elastomeric (rubber-like) constituents. And if the base biodiesel is out of spec then it will worsen the problems caused by bad biodiesel.

Where can information be obtained about what the major fuel distributors are blending and offering for sale in various geographic areas?

Check out the National Biodiesel Board website (http://www.biodiesel.org) for maps of producers and retailers. There are also lists of what products are sold at each retail location.

What are the state or Federal requirements for filling stations to post blending percentages?

At present, pump labeling is an individual state issue. There is no Federal mandate to label biodiesel pumps.

- Thanks to Shailesh Lopes and Andrew Buczynsky

An innovative new 2-Way Advanced Remote Start kit is available for installation in select 2007-08 GM vehicles, including Enclave, Lucerne, Avalanche, Equinox, HHR, Silverado, Suburban, Tahoe, G6, Acadia, Sierra, Yukon, Escalade and H2. The kit includes a receiver (RCDLR), key fob transmitter with LCD display screen (fig. 6), antenna and owner manual.

TIP: Depending on vehicle equipment, the kit may also include a factory style 1-way transmitter, a service part ID label, authorization code to reprogram the vehicle to add remote start (similar to the current remote start accessory kits), a hood latch and a hood switch wiring harness.

TIP: The kit can be ordered through the local Accessory Distributor Installer (ADI) or the dealership parts department. 

This upgrade adds functions to the factory keyless entry or remote start systems, and the 2-way feature allows the owner to view various vehicle data on the key fob's LCD display screen.

Availability of features and displays varies by vehicle and other equipment. Depending on model, functions include*:

- extended range remote keyless entry

- extended range remote vehicle start

- door lock/unlock

- power liftgate open/close

- scroll through preset radio stations

- vehicle locator/panic alarm

* A 2-way Advanced Remote Start Vehicle Model/Function Matrix is available on the Accessory Information Center (AIC) via DealerWorld.

And also depending on model, the LCD screen displays:

- fuel level

- tire pressure

- odometer

- clock/remote start countdown timer

- key fob battery life indicator

- visual (and audible) confirmation that key fob commands were received

Transmitter Types

There are three types of 2-Way transmitters, depending on the equipment on the vehicle:

- 4-button with a trunk/liftglass/power liftgate button

- 4-button with a panic button

- 5-button with both a liftglass and a power liftgate button

The appearance of the fob control buttons varies slightly depending on vehicle equipment, but basically all fobs have four or five buttons on the top face and one button on each side. The face buttons control typical remote functions (lock/unlock, start), while the side buttons are used to navigate the various feature menus of the Advanced Remote Start fob (radio, odometer, tire pressure, fuel level, etc.).

Owner Benefits

The 2-way fob has an operating range up to three times as far as the factory installed system. It is able to pre-heat or pre-cool the vehicle interior (when temperature is pre-set). It can be programmed to control a second vehicle that is also equipped with the 2-Way Advanced Remote Start system. And factory key fobs remain operational if reprogrammed (except HHR and G6; the kits for these vehicles include one new factory-style key fob to replace the factory fob).

Installation Tips

Estimated installation time runs from 1.1 to 2.3 hours, depending on the vehicle. Installation instructions are not in the kits. They are available on SI. There is an Accessory Installation Manual for each vehicle.

The installation involves replacing the RCDLR on the vehicle with the 2-Way RCDLR and installing the antenna in a location specific to each vehicle make/model. The antenna is mounted with double-sided adhesive tape, which requires one of the following adhesion promoters (not included in the kits).

TIP: The antenna mounting location described in the instructions is very important for achieving the transmitter's optimal operating range and tire pressure sensor receiving performance of the system.

Programming Tips

The 2-Way RCDLR is programmed using SPS. This is common with how Omron RCDLRs are set up, but not common with how Lear RCDLRs are set up. For most vehicles, there is a series of questions that need to be answered about the vehicle to narrow down the correct calibration file. Options that the system cares about are steering wheel remote controls (UK3), power liftgate (E61) and radio option for fullsize trucks.

One of the questions for the full size pickups only is whether the vehicle has the Tire Pressure Monitoring System (not on some heavy-duty dually pickups). If you incorrectly answer that the vehicle doesn't have TPMS, the IPC TPMS telltale will be illuminated, but there will be no DTCs in the 2-Way RCDLR.

Service Tips

Because the 2-Way RCDLR replaces the regular production RCDLR, service of RCDLRs in the future will require determining which part to order for replacement:

- an RCDLR from the regular production section of the catalog (Group 16)

- or the Accessories 2-Way RCDLR from the Accessories section of the catalog (Group 21).

- or a 1-way transmitter from the Accessories section of the catalog (Group 21).

Identification Tips

The 2-Way RCDLR has a bright yellow label on it.

The Tech 2 shows "Code" as the supplier of the RCDLR under the Module ID information.

The 2-Way transmitter is a positive indicator that the vehicle is equipped with the optional system, but if the customer brings in only the factory-style transmitter, the vehicle could still be equipped with a 2-Way RCDLR. A SPID label indicating that the 2-Way Advanced Remote Start system has been installed on the vehicle is included in the HHR and G6 kits.

Operating Tips

The 2-Way Advanced Remote Start owner manual states that the transmitter's odometer display is accurate within one mile, and the clock is within a couple of minutes. The odometer should normally not differ from the IPC. Differences are slightly more probable on Acadia and Enclave.

The fob clock will likely be one minute behind the clock on all applications. When the fob synchs with the vehicle, it gets only the hour and minute information, not the seconds, and it assumes that there are zero seconds. This, combined with the fact that some radios send time of day as exactly one minute behind what is on the display, will cause the clock to be two minutes behind on some vehicles. This is normal operation.

The fob fuel level display is approximate (only shows 5 bars) so it does not exactly represent the IPC fuel gage pointer position. The point at which a particular bar will disappear will be consistent for the life of the vehicle, but may differ from a vehicle of a different model. For instance, if the 2-way fob is used for two different vehicles, there may be discernible differences when compared to the IPC fuel gages.

- Thanks to Joyce Henk and Sharon Folts

This information applies to the 2007-08 Acadia and OUTLOOK and the 2008 Enclave. According to bulletin 07-08-110-001A, the 2nd or 3rd row floor mat may not lie flat.

The floor mat retainer posts may be located too close together, so the post and retainer in the mat do not align (fig. 7).

Gently pry apart the appropriate retainer from the underside of the mat (fig. 8). Enlarge the cutout in the mat a maximum of 0.12-0.16 in (3-4 mm) to allow the retainer to shift the amount necessary to align to the post spacing (fig. 9).

IMPORTANT: Be sure to enlarge on the proper side of the cutout.

TIP: In some cases, all cutouts may need to be enlarged.

Reassemble the retainer to the mat. Before pressing the two halves of the retainer together, apply a thin coat of Instant Gel Adhesive, p/n 12345632 (10953475 in Canada) or equivalent, to the inside flange of the lower piece (fig. 10). This will secure the retainer to the backside of the mat and prevent movement of the retainer.

- Thanks to Gary McAdam

On some 2007-08 Cadillac DTS vehicles equipped with 4T80E MH1 transmission, a ticking/fluttering noise can be heard in the vehicle at highway speed.

The noise is generated by the modulation of the TCC solenoid. Movement within the solenoid excites the shift cable, resulting in a low level, high frequency noise that can be heard in the passenger compartment

To correct the condition, install a solid lead clamp mass damper to the cable
(figs. 11 and 12). This has been shown to significantly reduce or eliminate the noise.

Contact BQM Darryl Butler at 586.575.7478 or email to darryl.a.butler@gm.com to obtain the damper.

- Thanks to Darryl Butler