May 2010 Archives

(Fig. 1)

The Buick Regal is a new midsize sport sedan for 2011. (Fig. 1) Two models will be offered. Initially available, the CXL is equipped with a 2.4L DOHC SIDI 4-cylinder ECOTEC engine (RPO LAF) producing 182 horsepower and 172 lb.-ft. of torque, accompanied by a 6-speed automatic transmission with Driver Shift Control. The estimated U.S. fuel economy will be 20/30 mpg city/highway. (Estimated Canadian fuel efficiency of 10.8 L/100 km city and 6.5 L/100 km highway.)

Introduced later in the model year, the CXL Turbo will be equipped with a 2.0L DOHC SIDI 4-cylinder ECOTEC engine (RPO LHU) producing 220 horsepower and 258 lb.-ft. of torque, accompanied by a 6-speed automatic transmission with Driver Shift Control, or an available 6-speed manual transmission. The estimated U.S. fuel economy will be 18/29 mpg city/highway.

The Regal is based on GM's global front-wheel-drive architecture. It features an independent MacPherson strut front suspension, four-link independent rear suspension, hydraulic rack-and-pinion power steering, four-wheel disc brakes with ABS, StabiliTrak^® Stability Control, and Traction Control System.

2.4L ENGINE (LAF)

The 2.4L engine (Fig. 2) uses Spark Ignition Direct Injection (SIDI) and variable valve timing to provide equivalent horsepower with less fuel consumption.

(Fig. 2)

With long-life coolant and spark plugs, the 2.4L engine requires no routine maintenance other than engine oil, oil filter and air cleaner for the first 100,000 miles (160,000 km).

2.0L TURBO ENGINE (LHU)

The 2.0L turbo engine features dual overhead camshafts and 4 valves per cylinder, common rail multiple fuel injectors and a variable geometry dual-scroll turbocharger. It is fuel-efficient, while providing V6-like performance (7.4 seconds 0-60 mph).

It features a cast-in oil filter housing that no longer requires a technician to go under the vehicle to perform an oil filter change as well as eliminates throwaway oil filter cans.

DRIVER SHIFT CONTROL

This feature permits shifting the automatic transmission manually for sporty driving, or to provide engine braking on a downhill grade. Move the shift lever to the left of Drive. Then tap forward to upshift and rearward to downshift. (Fig. 3) If the vehicle speed is too high or too low for the requested gear, the shift will not occur.

(Fig. 3) 

INTERACTIVE DRIVE CONTROL SYSTEM

This driver-selectable system is available on the CXL Turbo. An electronic control module constantly monitors the driving style along with vehicle state, including acceleration, braking and cornering. It adapts and adjusts chassis behavior based on the mode selected by the driver.

Drive Mode Control software recognizes 11 different driving situations: cruising, acceleration, accelerating in corner, braking, braking in corner, cornering, low speed, vehicle stopped, transient, reverse, and stabilization.

TIP: The Standard Mode is active each time the vehicle is started. Sport and Tour Modes are selected and de-selected with the pushbuttons on the center of the instrument panel.

Standard Mode - Four electronically controlled dampers continuously adapt within milliseconds to prevailing road conditions, vehicle movement and individual driving style.

Sport Mode - For enthusiastic driving, the Sport Mode stiffens the dampers, offers swifter throttle pedal response, reduces power steering assistance, offers more proactive transmission shifting, and raises the threshold of StabiliTrak intervention.

Tour Mode - For long distance driving, the Tour Mode adjusts the ride, dampers, power steering, shifting and StabiliTrak accordingly. In emergency situations, dampers are stiffened within milliseconds.

NAVIGATION RADIO

This is not a touch screen system. Menus are accessed by using the 4-way control pad in the center of the menu/select knob and the outer chrome ring on the knob. (Fig. 4) When the vehicle is moving, various on-screen functions are disabled to reduce driver distraction.

 (Fig. 4)

The system features 10 GB of hard drive space to record audio files. It also offers the audio timeshift function to play/pause live radio.

The system also has a multi-function knob on the center console that provides access to navigation, audio and phone functions. (Fig. 5)

(Fig. 5)

USB/BLUETOOTH

 A 3.5mm auxiliary input jack and a USB port, which can be used to control iPod^® and MP3 devices, are located in the storage compartment of the center console.

A portable device connected to the auxiliary input jack can be controlled only by using the portable device controls. To optimize speaker volume, fully increase the volume level of the portable device.

Compatible devices connected to the USB port can be controlled by the audio system. Not all devices may be supported. Use the menu/select knob and the audio steering wheel controls to access various functions.

The in-vehicle Bluetooth^® system allows users with a Bluetooth-enabled cell phone to make and receive hands-free calls using the vehicle's audio system, microphone and controls. The Bluetooth-enabled cell phone must be paired with the vehicle's Bluetooth system before it can be used in the vehicle. Not all phones will support all functions.

ELECTRIC PARKING BRAKE

An electric parking brake replaces the conventional manual parking brake. It's operated using the switch on the center console.

·       To apply the parking brake, pull up the switch.

·       To release the parking brake, turn on the ignition, press the brake pedal and press the switch.

LOCKING FUEL DOOR

The fuel door cannot be opened or closed if the vehicle doors are locked.

To open the fuel door, press the center rear edge of the door; it will pop open slightly.

POWER WINDOWS

All windows have an express-down feature. Only the front windows have an express-up feature.

TIP: If vehicle battery power is lost, the power windows must be reprogrammed according to the owner manual procedure for the express-up feature to operate.

ULTRASONIC REAR PARKING ASSIST

When the vehicle is in Reverse, detected objects are indicated by audible beeps, which become more frequent as the vehicle gets closer to an object.

TIP: This system uses only audible beeps, not indicator lamps.

TRANSPORTATION MODE

TIP: Be sure to disable Transportation Mode before delivery of the vehicle to a customer to avoid unnecessary customer concerns and warranty expenses.

Transport Mode/Battery Saver Relay is designed to extend the battery charge of a vehicle during shipment or extended storage. When activated, it shuts down modules and accessories that do not affect FMVSS (or CMVSS) requirements. Modules in power reduction hibernation will vary depending on how the vehicle is equipped, and may include HVAC afterblow, lighting timers, content theft system and LED, radio, chime module, suspension control module, RFA, and others.

The vehicle may be started and driven in Transportation Mode but will have reduced functionality.

How to Change Modes

This procedure can be used to change from In-Transport mode to Out-Of-Transport mode, and vice versa.

1.     Press the hazard warning flashers button.

2.     Press and hold the brake pedal.

3.     Start the engine and hold the ignition key in the Start position for 15 seconds.

 When active, the Transport Mode message will display on the DIC and the battery symbol will flash on the instrument cluster (Fig. 6); when being deactivated, the Transport Mode message will disappear from the DIC.

(Fig. 6)

- Thanks to Eric Kenar

Recently, Microsoft significantly limited the availability of the Windows Vista^® operating system. The GM dealership PC guidelines published in September 2009 indicates the recommended operating system (OS) is Vista Business, 32 bit.

In response to the availability of the recommended Vista OS, the Techline team has worked with each PC reseller, DESolutions, GMDIT and DES-Canada, to include Windows 7 Professional^®, 32 bit, along with a downgrade to XP Professional^®, with any new computer purchase.

At this time, the Windows 7 operating system is not approved or supported by GM; however, approval is expected in the next few months. Dealership personnel should use the XP operating system until Windows 7 is approved. Once the new OS is approved, the dealership guidelines will be revised to reflect the recommended change. The Vista OS also will continue to be supported.

For more information, contact GM Dealer Equipment at www.gmdesolutions.com (in Canada, www.des-canada.ca) or Techline at 1-800-828-6860 (English) or 1-800-503-3222 (French).

- Thanks to Lisa Scott

Midtronics Battery Tester/Charger

(Fig. 7) 

Shipments have begun of the EL-50313 Midtronics Battery Tester/Charger (Fig. 7), which replaces the Midtronics (J-42000-EU) hand-held battery tester. The new tool was developed by Midtronics Corporation, GM Engineering and GM Service Operations to offer the most advanced features for diagnosing and charging 12-volt batteries.

TIP: Be on the lookout for an announcement bulletin.

In addition to the conductance testing features of the earlier tool, the new equipment has added several important features: 150 Amp Load Test, 73 Amp (peak) Charge, Dynamic Testing and PDI Mode. It is designed to quickly recharge even deeply discharged batteries.

The PDI mode will replenish the battery as safely as possible in 20 minutes. The PDI feature should be used when a new vehicle arrives at the dealership, at 30 day intervals while the vehicle is in inventory, and when the vehicle is delivered to the customer.

The EL-50313 is equipped with a built-in printer to provide permanent printed documentation of test results for the vehicle's file. The printout includes such useful information as the battery's state of health, measured and rated CCA, and the charge delivered.

Similar to the earlier J-42000-EU, the new tool provides a unique ten-digit code for use in preparing warranty claims.

Other important features include jump-start capability, controlled power supply for use during reprogramming, and compatibility with both conventional (flooded) and AGM batteries. The built in countdown timer helps determine when to tell the customer to expect charging to be complete.

When properly used, the EL-50313 will help reduce battery replacements, minimize battery scrapping, and reduce battery handling in the dealership.

For additional information, refer to the March Emerging Issues seminar (U.S. dealers). Dealers in Canada should refer to the April TAC Talk VOD.

- Thanks to Len Tillard

There may be some possible discoloration of the ebony cloth seats on some 2007-2009 full-size trucks with cloth seats (RPO AE7) and on 2010 and beyond full-size trucks with cloth seats. The discoloration is most likely attributable to dirt, not seat wear.

To address any concerns about discoloration of the cloth seats, thoroughly clean the seats using a high powered canister vacuum to remove any imbedded dirt or debris. The cloth seats will have a noticeable difference in appearance before cleaning (Fig. 8) and after cleaning. (Fig 9)

 (Fig. 8)

(Fig. 9) 

If the seats cannot be cleaned satisfactorily, replace the seat trim assembly.

- Thanks to Maurine Miller

On some 2008-2010 Enclave; 2007-2010 Equinox, Acadia; 2007-2009 Torrent, OUTLOOK; 2008-2009 VUE; 2010 Terrain; and 2009-2010 Traverse models equipped with All-Wheel Drive, the All-Wheel Drive System may become inoperative with a Service All-Wheel Drive (Service AWD) light On. There may be other various conditions related to a low battery, such as but not exclusive to a no crank or slow engine crank condition or the vehicle may have been jump-started recently.

The vehicle is still operational in two-wheel drive mode. Technicians may find DTC C0550 set as a current or history DTC in the Clutch Control Module (CCM). This may occur due to low voltage presence in the system.

If DTC C0550 is stored in the CCM, follow these steps prior to replacement of the CCM:

1.     Verify that DTC C0550 is set as a current DTC or history DTC in the CCM.

2.     Check that the battery voltage level is above 9 volts. If the battery voltage level is low, perform a charging system diagnosis, parasitic draw test and battery load test. Repair as necessary.

3.     Clear DTCs and turn off the ignition for at least 2 minutes.

4.     Turn on the ignition and wait for 40 seconds. If DTC C0550 does not reset in the CCM, it may have been induced by a low voltage condition. If DTC C0550 resets as a current DTC, follow the normal SI diagnostic procedure.

- Thanks to Dave MacGillis

If the Check Engine Light illuminates intermittently and DTC P0172 is set on some 2010 Malibu models equipped with the 2.4L engine (RPOs LE5, LE9), the alcohol content information in the PCM should be verified.

Use the following procedure to determine if the PCM has the incorrect alcohol content information. Refer to bulletin #10-06-04-004 for more information.

1.   Verify the actual measured percentage of alcohol content using the J 44175 tester or the J 44175-A tester. If the actual alcohol is less than 15%, determine the fuel alcohol content using the Tech 2.

2.   Build the vehicle on the Tech 2 and select Powertrain.

3.   Build the vehicle with an LE9 engine (even if it has the LE5 engine).

4.   Select Special Functions (F2) > Fuel System (F2) > Fuel Composition Reset (F1)

5.   The first parameter is Fuel Alcohol Content, displayed as a percentage. If the fuel alcohol content percentage is above 25%, this is the probable cause of DTC P0172. (Fig. 10)

(Fig. 10) 

6.   From this screen the Fuel Alcohol Content parameter can be reset to zero by pressing the lower right Tech 2 button. It will display 0% when reset. (Fig. 11)

(Fig. 11) 

TIP: The PCM must be reset from this screen. It does not reset to zero when the PCM is reprogrammed.

7.   Reprogram the PCM with the latest calibration to correct the PCM alcohol calculations.

- Thanks to Dave Peacy

A Service Charging System message may be displayed on the DIC and/or a low voltage reading may be shown on the volt gauge during the first several minutes after a cold start on some 2007-2010 Silverado or Sierra models equipped with the 6.6L diesel engine (RPO LMM). Some modules may set DTC B1517, SYM 03-Battery Voltage below Threshold.

If this condition only occurs during the first several minutes of a cold start, no repairs should be made. This is a normal operating characteristic of vehicles equipped with the diesel engine.

During a cold engine start (Cold is an engine coolant temperature below 100° F or 40° C), the intake air heater and the glow plugs are commanded on to help reduce emissions and improve cold weather driveability. The intake air heater can draw 130 amps at 100% duty cycle for up to 10 minutes. The glow plugs can draw up to 110 amps with cycle times up to 3 minutes. These two loads, in addition to the normal loads from the vehicle (example: blower, lights, heated seats, etc.), can exceed the maximum generator output (125 amps in most cases). Due to these high current loads, the Service Charging System message may display during the first several minutes after a cold start.

- Thanks to Jim Will

Service Information states to install the rear wheel bearing on a 2008-2009 G8 so the decoder ring faces inboard toward the wheel speed sensor. To determine which side of the bearing is the decoder ring side, compare the sides of the bearing. The decoder ring side of the bearing is dark in color (not metal color) and also is magnetic. (Fig. 12)

(Fig. 12) 

The opposite side of the wheel bearing that is not magnetic (Fig. 13) should be installed outboard, facing away from the wheel speed sensor.

(Fig. 13)

- Thanks to Dave Eplin

A test lamp can light with up to 200 Ohms in a ground or low reference circuit, so it is not recommended to be used for this type of test. Instead, use a Digital Multi-Meter (DMM) when validating ground or low reference circuit continuity. Updated information about testing ground and low reference circuits is now available in the Service Information (SI).

TIP: For 2007 and later vehicles, click the Circuit Testing link in any SI diagnostic procedure, then select Testing Ground and Low Reference Circuits.

When using a DMM, there are many vehicle conditions that can affect the ground and low reference continuity testing. If these conditions are not met, a ground or low reference circuit test can fail on a good circuit, causing longer diagnosis time and incorrect component replacement.

Any current flow through a ground or low reference circuit while being tested will skew the DMM continuity reading, or display a reading higher than when there is no current flowing.

Performing a ground or low reference circuit continuity test in reference to the vehicle's battery negative terminal will have the highest risk of failing a good ground or low reference circuit test than any other ground reference point. The best ground test points are a control module's housing (if the housing is metal and grounded), door jamb striker (if attached to metal), under dash metal framework, engine block, or body ground studs (other than where the negative battery cable is attached).

A typical DMM ground or low reference circuit continuity reading can be as high as 100 Ohms with the ignition On and drop to 15-25 Ohms after the ignition is turned Off. The reading will drop below 10 Ohms after 30-40 seconds, and then below 5 Ohms after 60 seconds. Once the vehicle completely goes to sleep (generally 3-10 minutes) the reading will drop below 0.3 Ohms.

Conditions that may need to be met to ensure a valid continuity reading on a ground or low reference circuit include:

·       Ignition Off

·       Key out of the ignition switch

·       Retained Accessory Power (RAP) Off

·       Battery charger set at a 2 Amp or less charge rate

·       No scan tool communication with a control module

·       All access doors closed

·       Headlamps Off (Auto headlamps disabled)

·       Any delay lighting Off

·       HVAC afterblow Off

·       Any accessories Off that can work when the ignition is Off

·       Wait up to 60 seconds (after all other listed conditions are met)

TIP: Activating the door lock function with a key fob can greatly reduce the time to achieve a valid ground or low reference continuity test result.

- Thanks to Dave Nowak

When servicing a fuel line on a Spark Ignited Direct Injection (SIDI) fuel system on the Ecotec engine family (2007-2010 LNF, 2009-2011 LDK, 2010-2011 LAF, and 2011 LHU) and the HFV6 engine family (2008-2011 LLT, 2010-2011 LF1, and 2011 LFW), the fuel pipe must always be replaced when it incorporates a tube nut fitting. (Fig. 14)

(Fig. 14) 

If a tube nut fitting is loosened for a fuel system repair, the line must be replaced because, after the tube nut is torqued the first time, the sealing surface on the ball end of the pipe becomes modified in a way that will not seal properly again. The ball end of the pipe is a softer material than the mating surface and, once pressure is applied from torquing the tube nut, it deforms to form a good seal.

It can be determined that a fuel pipe has been previously installed by viewing the ball end of the pipe. After the tube nut fitting has been torqued once and re-installed, the sealing surface of the ball end will show dual sealing bands, indicating that the pipe has been previously installed. (Fig. 15)

(Fig. 15) 

If a pipe has been removed only once, it will only show one sealing band. Because of the deformation that takes place on the first tightening, the material may not seal properly the second time, which is why the fuel pipe must be replaced.

TIP: New fuel pipes are ready to use right out of the package. A blue or transparent dry lube may be noticed on the ball ends of the pipe. Do not wipe off this lube. It aids in achieving proper torque and sealing at the ball end fitting of the pipe.

It's important to follow SI procedures any time the fuel system is serviced. Be sure to properly inspect, clean and torque the fuel pipe mating surfaces. Also, some fuel pipes have specific torque sequences that must be followed to ensure a good seal.

- Thanks to Bryan Salisbury

Some 2007-2010 Silverado or Sierra models equipped with an Allison LCT1000 transmission (RPO MW7) may have the transmission over-temperature or hot temperature light illuminate with various shifting or engagement concerns and/or the Service Engine Soon light may illuminate. These conditions may be intermittent and a combination of powertrain DTCs may be set.

Inspect the transmission main wiring harness near the bell housing area. (Fig. 16)

(Fig. 16) 

The harness may become pinched between the body, clip and the bell housing. (Fig. 17)

(Fig. 17) 

Inspect all wires within the harness and repair as necessary. Reposition the clip and harness to eliminate the pinching condition.

- Thanks to Chuck Krepp

Some customers with a 2010 SRX, Equinox or Terrain may comment that the rear wiper and/or the front Rainsense wipers (SRX models, if equipped) turn off when the vehicle is shifted to neutral. This is called Car Wash Mode.

The intent of Car Wash Mode is to disable the wiper(s) while in an automatic car wash to avoid potential damage to the wiper arms. For the rear wiper and/or the front Rainsense wipers to be disabled, the vehicle must be traveling below 3 mph (5 kph) and the transmission must be in Neutral. The Rainsense-equipped wipers lever (Fig. 18) must be in the Intermittent position (between O and 1) or the rear wiper switch must be On.

(Fig. 18) 

Once the wipers have been inhibited, normal wiper operation will not return until the transmission has been shifted out of Neutral for 10 seconds or vehicle speed is greater than 3 mph (5 kph).

Do not replace any parts for this condition. Refer customers to the vehicle owner manual for additional information about wiper operation.

- Thanks to Ron Erman

During PDI inspection, oil change inspection or other routine maintenance on some 2010 LaCrosse, SRX, Camaro, 2009-2001 Escalade, Escalade ESV, Escalade EXT, Colorado, Silverado, Suburban, Tahoe, Canyon, Sierra, Sierra Denali, Yukon, Yukon Denali, Yukon XL, and Yukon Denali XL models, it may be noticed that the axle fluid appears milky or contaminated with water or gray material. The discoloration in the fluid may be found in either front, rear or both axles.

During manufacture of the axles, a white or yellow gear rouge or marking compound is used when the tooth contact pattern on the gear set is inspected. The marking compound colors the fluid a milky or semi-metallic gray (this color combination sometimes appears similar to metal or water in the fluid).

The coloring only lasts between 1,000 and 5,000 miles (1,609 and 8,046 kilometers), after which the fluid appears normal. If there are not any noise concerns, do not attempt any repairs for the discolored fluid on vehicles with fewer than 5,000 miles (8,046 km).

- Thanks to Chuck Krepp

Some 2010 Impala models built between August 24, 2009 and October 27, 2009 may have corroded or pitted chrome on the outer belt moldings located below the side windows. (Fig. 19)

(Fig. 19) 

The corrosion/pitting also may be described as rusty or blemishes to the surface. (Fig. 20)

(Fig. 20)

The corrosion/pitting may be found on one or all four moldings on the vehicle. Check GMVIS for the build dates of any Impala models in for service with this condition.

If an identified vehicle with this condition is brought in to the dealership, replace the moldings. Do not try to clean or buff out the corrosion/pitting because it will return.

No other chrome on the vehicle is affected with this same condition.

- Thanks to Dave Eplin

If a 2010 CTS, CTS Wagon, STS, LaCrosse, Camaro, Traverse, Enclave or Acadia equipped with the direct injected 3.6L V6 engine (RPO LLT) has a set DTC P2101, check several circuits from the ECM. The cause of DTC P2101 being set will most likely not be the ECM.

Check circuits 485, 486, and 2752 from the ECM to the throttle body. Be sure to test the pin tension at the throttle body and the ECM. Replace the circuits if necessary.

- Thanks to Ron Mitchell

10210.05D - Emerging Issues

May 13, 2010

To view Emerging Issues seminars:

Log in to www.gmtraining.com, select Service Know-How/TECHAssist from the menu, select Emerging Issues, and then Searchable Streaming Video to choose the current Emerging Issues seminar or past programs.