Archive for 2014

New 2015 City Express Ready to Work

The all-new 2015 Chevrolet City Express small cargo van (Fig. 1) is a small Euro-style work van designed for businesses that need to move cargo but do not need the capabilities of a full-size van. It’s offered in LS and LT trims.


F01 2015-chevrolet-city-express

Fig 1


The van is equipped with a 2.0L inline-4 cylinder DOHC engine and front wheel drive via a continuously variable transmission (CVT). The front suspension features MacPherson struts with coil-over springs, twin-tube dampers and a stabilizer bar. The solid axle rear suspension has twin-tube shock absorbers and truck-style multi-leaf springs. Electric power steering provides a tight turning diameter of only 36.7 feet (11.2 meters).




The 2.0L inline-4 Cylinder, DOHC gasoline engine (RPO L0A) (Fig. 2) features continuously variable valve timing engine, sequential multi-port fuel injection and a cast aluminum engine block and cylinder heads. The engine is rated at 131 hp (98 kW) at 5,200 rpm and 139 lb.-ft. (188 Nm) of torque at 4,900 rpm.


F02 2015 city express engine

Fig 2

The CVT8 continuously variable transmission (RPO MRA) (Fig. 3) optimizes torque delivery across the rpm band. GM recommends using ACDelco CVT Fluid, P/N 19260800 (in Canada, use P/N 19299096). Do not mix CVT fluid with any other fluids and do not use automatic transmission fluid or manual transmission fluid.


F03 2015 city express cvt

Fig 3


Cargo Features


The City Express has a payload capacity of 1,500 pounds (680 kg) and a customizable cargo space volume of 122.7 cubic feet (3,474 liters). Cargo can be secured with the six steel floor-mounted D-rings with reinforced weld nut mounting points. The 54.8 inches of space (1.39 meters) at the floor from side wall to side wall provides enough room to load a standard 40 x 48 inch (1.01 x 1.22 meters) pallet flat on the floor.


The standard sliding doors on both sides of the vehicle are designed for low effort operation and convenient access. (Fig. 4)


2015 Chevrolet City Express

Fig 4


The tall rear doors are a 40/60-split design. (Fig. 5) The 60-percent door is on the passenger side for easy access from the sidewalk. The 40-percent door on the driver side is shorter, reducing potential intrusion into the street when open. Both rear doors feature dual opening positions of 90 degrees and 180 degrees.

 F05 2015 city express rear doors

Fig 5




The Driver Information Center (DIC) display on the instrument cluster (Fig. 6) provides a variety of vehicle data, including trip odometers, instant fuel economy, average fuel economy, distance-to-empty mileage and outside temperature (optional).


F06 2015 city express dic

Fig 6


The City Express LT model is available with a Technology Package that includes:

• A color connected radio with color touch screen display (Fig. 7)

• Bluetooth® streaming audio for music and select phones and hands-free smartphone integration

• AM/FM radio with CD player

• GPS navigation

• SiriusXM Radio

• Rear Vision Camera (RVC) with Rear Parking Assist.


F07 2015 city express radio

Fig 7


Training Courses


Training courses for the 2015 City Express can be found at (U.S.) or (Canada).


Available training currently includes:

• 10214.14W – New Model Features Course

• 16440.19D – New Engines and Updates Course (U.S. Only)


For additional information, refer to #PI1362: New Model Features and Information.



– Thanks to Sherman Dixon and Calvin Williams

Update Tech2Win for Latest Diagnostics

The Tech2Win application first released to GM dealerships in 2011 is a version of the Tech 2 and CANdi (Controller Area Network diagnostic interface) module loaded onto a Techline PC or laptop computer via TIS2Web. Technicians can take advantage of the computing power of their PC or laptop computer as well as the speed of the MDI — when using Tech2Win, vehicle communication is performed using the Multiple Diagnostic Interface (MDI) — for faster operation, more convenience and added diagnostic capabilities.


Using it on a PC or laptop computer (Fig. 8) that also has GDS 2 installed provides all diagnostic tools on one computer. Plus, with a laptop computer, Tech2Win can be used during a vehicle road test, offering a larger screen with all of the Tech 2 tool capabilities. Tech2Win also supports touch screen functionality.


F08 tech2win main screen

Fig 8


Tech2Win Features


The Tech2Win application offers most of the features and functions of the Tech 2. Tech2Win:

• Is used for diagnostics only. Service programming is still performed through TIS2Web SPS.

• Requires a license that must be updated every 30 days, similar to the license renewal of GDS 2.

• Requires PC and laptop computer specifications that meet or exceed the current minimum Techline hardware specifications. Review the latest specifications and guidelines at (In Canada, the IT guidelines are in the Service Library under Tools, Processes and Equipment on Global Connect.)


Access for All


The Tech2Win application does not require any special access or other tools or software. When selecting the Tech 2 software download on TIS2Web, a prompt will ask if you want to install Tech2Win.


After installing the Tech2Win application, a software download also will be required to download the desired diagnostic software for the desired vehicle coverage.


Installing the Tech2Win Application


To install the application:


1. Connect the MDI to the computer. Power it using the AC adapter.

2. Select the Tech 2 software download on TIS2Web. A prompt will ask if you want to install Tech2Win. It can be installed on multiple PCs in the dealership.

3. Install the Tech2Win application using all the default selections. Installation should take less than 10 minutes.

4. Two icons will be placed on the PC desktop — a shortcut for Tech2Win QuickStart and a shortcut for the Tech2Win Configurator, which is used for multiple versions of Tech2Win depending on the vehicles being serviced in the dealership.


After the application installation is complete, the diagnostic software for the desired service coverage and software license must be obtained. To download:


1. Click the Tech2Win QuickStart icon that is now on the PC’s desktop.

2. Since Tech2Win does not have a current license, a license dialog box will appear. Click OK.

3. When the MDI is detected, a dialogue box will direct you to select the vehicle communication interface.

4. To initiate the software license and install the diagnostic software, select the Software Download (SWDL) on TIS2Web and click Start Software Download. (Fig. 9)


F09 software download

Fig 9


5. Select Tech2 and Custom for the update mode. (Fig. 10)


F10 diagnostic tool screen

Fig 10



6. Select the desired diagnostic software package. (Fig. 11)


F11 select app

Fig 11


7. Click Download to begin downloading the diagnostic package. Current progress and Tech2Win will display during the download.


After the download is complete, the license countdown in the lower right corner will be updated to 30. This is the number of days until the license must be renewed. When the license expires, an expiration message will be displayed. To renew the license, use the security access service or update the diagnostic software using the standard update mode.


Tech2Win uses Communication Port (comm port) 9 on the PC. If this port is used for other devices, switch the comm port setting by selecting the Tech2Win Configurator icon on the desktop. Refer to the Quick Reference Guide for complete details.


When using Tech2Win, you can click the selections on screen or click the soft buttons on the screen where applicable.


Tech2Win activity is shown on the bottom of the screen between the vehicle, MDI, Tech2Win and the PC. (Fig. 12)


F12 tech2win activity

Fig 12


To access the Quick Reference Guide for additional Tech2Win installation information, go to TIS2Web News and select the Tech2Win Quick Reference Guide.


– Thanks to Chris Henley


New Categories for Customer Concern Not Duplicated Codes

The Customer Concern Not Duplicated (CCND) labor codes have been updated with new categories as of December 1, 2014.The new categories cover areas of the vehicles not previously covered by CCND labor codes.


In addition, updates have been made to the Body/Electrical categories to remove duplicate titles for different labor codes.


Be sure to use the appropriate CCND labor code based upon the customer concern. The correct codes help the related GM engineering team to more quickly identify trends that can be addressed with product improvements and/or bulletins.


Updated Body/Electrical CCND Categories


Following are the updated Body/Electrical categories, the specific labor code and an example of a customer concern. Keep in mind that multiple systems or features may fall under the same labor code.

Screen Shot 2014-12-17 at 3.28.37 PM


New CCND Categories


Following are new CCND categories to cover previously undocumented vehicle areas.


Screen Shot 2014-12-17 at 3.29.24 PM


All labor codes, including CCND codes, can be found it the Labor Time Guides in the Service Information. Use the drop-down menus to build the desired model to view the applicable Labor Time Guide. For a complete list of CCND labor codes, refer to the latest version of Bulletin #06-00-89-026.


– Thanks to Bob Wittmann


ASE Now Offers Year-Round Testing

Automotive Service Excellence (ASE) has recently announced that testing is now available 12 months of the year.


After technicians register for testing during one of the four registration windows, they will always have 90 days to schedule an appointment and take the test. This means that whether you register on the first day of registration or the last day, you will have 90 days from that date of registration to complete the test.


Besides being more convenient, the year-round testing should help reduce the amount of last-minute testing taken at the end of previous testing periods. There will continue to be four testing periods — winter, spring, summer and fall — throughout the year.


ASE Test Centers


ASE tests are conducted at more than 450 Prometric test centers across the country.

Click below to see what to expect at an ASE test center when taking an ASE computer-based test. (Fig. 13)


F13 ase video image

Fig 13


Winter Registration


December 1, 2014–February 20, 2015


Register using the myASE LOGIN at or call Prometric at 1-877-346-9327.


Winter Testing


Begins December 1, 2014 and runs continuously


– Thanks to Mike Durkin

Hood Bumpers and Latch Adjustment

The hood of a 2015 Colorado or Canyon may shake or flutter while driving due to misadjusted hood bumpers or the hood latch.


Use a piece of paper to check for proper contact of the outer and middle bumpers to the hood. The paper must not pull free when the hood is closed.


TIP: Do not place the paper over the headlamp. For the outboard bumpers, place the paper to the side of the headlamp and pull it over the fender. For the middle bumpers, place the paper to the front of the truck and pull it forward. (Fig. 14)


F14 4001655

Fig 14


Bumper and Latch Adjustment


If the paper can be pulled loose, the bumpers and latch are not properly adjusted. It will be necessary to raise the outer and middle hood bumpers (2 per side) (Fig. 15, 16) until the hood is flush with the fenders. Set the height of the bumpers to 22 mm off of the bracket surface and repeat the paper test.


F15 4001656

Fig 15


F16 4001657

Fig 16


If there is not enough contact and the hood is flush to the fenders, temporarily mark the position of the hood latch and use a 13 mm ratchet or wrench to loosen the hood latch bolts just enough so that the latch will move but is not completely free.


Lightly tap the hood latch to lower it straight down 1 mm (do not move it left or right) and retighten to 22 Nm (16 lb.-ft.) with a torque wrench.


After lowering the hood latch, lower the two inner bumpers (one on each side of the latch) (Fig. 17, 18) by 1/4 to 1/2 turn clockwise. Repeat until the closing effort of the hood is acceptable.


F17 4001658

Fig 17


F18 4001659

Fig 18


Perform the paper test on the inner bumpers after latch adjustment. There should be very little to no drag to remove the paper.


Sound Deadener


If the paper cannot be pulled loose, the bumpers and latch are in adjustment. Apply Kent® Ure-Foam Expandable Foam Sound Deadener or equivalent in two locations (one per side). (Fig. 19)


F19 4008665

Fig 19


Remove the hood insulator, if applicable, and inject foam into the second hole from the side. Aim the applicator nozzle straight to the back and begin to fill the cavity. Once half of the product has been dispensed, tilt the tip upward and slowly draw the applicator back as the last half of the foam is injected, ensuring the product is applied to the hood panel. Remove any excess foam that prevents the hood insulator from installing into the outer hole.


The following illustration shows a cross-section of the hood assembly. (Fig. 20) Apply the first half of the product in area 2. Apply the second half of the product in area 3.


F20 4039299

Fig 20


TIP: The Kent Ure-Foam Expandable Foam Sound Deadener takes up to three days to fully cure. Advise the customer that it may take up to three days before the maximum benefits of the sound deadener are realized.


Repeat the application of the sound deadener on the other side of the hood and reinstall the hood insulator.


Refer to #PIT5340 for additional information and part numbers.


– Thanks to Jeremy Richardson

Squeak Sound from HUD Area

On some 2015 Escalade and Yukon models equipped with a Head-Up Display (RPO UV6), a squeak sound may be heard at the top left side of the instrument panel while driving. The sound may be duplicated while the vehicle is parked by applying pressure up and down on the steering wheel. Do not use the tilt steering wheel feature to try to duplicate the sound. It also may seem that the sound is coming from behind the instrument cluster.


The sound may be caused by the Head-Up Display (HUD) lens rubbing on the HUD shroud. The HUD shroud is part of the upper instrument panel extension. (Fig. 21)


F21 3621783

Fig 21


The HUD shroud may have four areas with felt tape installed, which is inadequate to eliminate the squeak sound. (Fig. 22)


F22 4009586

Fig 22


To eliminate the squeak sound, add 1 mm-thick felt tape, obtained locally, to the full perimeter of the HUD shroud. (Fig. 23)


F23 4010421

Fig 23


– Thanks to Jim Will

Oil Leak after the Harmonic Balancer is Removed

There may be an oil leak condition after the harmonic balancer is removed or replaced on some 2015 Escalade models, 2014-2015 Silverado 1500, Suburban, Tahoe, Sierra 1500, Yukon models and 2014 Corvette, equipped with the 4.3L, 5.3L or 6.2L engine (RPOs L83, L86, LT1, LV3).


When reinstalling the harmonic balancer, a different bolt design may have been used than what was removed from the engine.


Gen 4 engines use a non-keyed harmonic balancer. The only part of the crank that is keyed drives the oil pump. The bolt has a friction material on the face. It does not seal the harmonic balancer to the crank.


Gen 5 engines use a keyed harmonic balancer that can see oil pressure. It uses both a 1 piece bolt and a 2 piece bolt and washer arrangement. It seals to the face of the crank.


If a Gen 4 bolt is used in a Gen5 engine, it will result in an oil leak.


Gen 5 and Gen 4 Bolt Identification


The bolts (Fig. 24) shown below are:

Bolt 1– Gen 5 engine

Bolt 2 – Gen 5 engine

Bolt 3 – Gen 4 engine


F24 4043626 Gen 5 bolts

Fig 24


Bolt measurements (Fig. 25) are:

Bolt 1 – 1 piece Gen 4 bolt: 1.869 in. (47.5 mm) at the flange

Bolt 2 – 1 piece Gen 5 Bolt: 2.055 in. (52.2 mm) at the flange


F25 4043629 GEN 5 balancer bolts 2

Fig 25


TIP: The LT1 engine dry sump uses a longer bolt due to the oil pump that is used on this system.


– Thanks to Richard Renshaw

False Side Blind Zone Alert

The Side Blind Zone Alert system may become active with no objects within range of sensors on some 2014 LaCrosse and Malibu models equipped with Obstacle Detection Side Active Safety (RPO UKC or UFT). If this occurs no DTCs will be stored.


The side blind zone alert system uses two side object sensor modules to notify the driver that an object is present in one of the driver’s side blind zones. An icon on the left or right side view mirror is illuminated when an object is detected. (Fig. 26) The side object sensor modules are located on each side of the vehicle behind the rear fascia.


2015 Buick LaCrosse 1SL AWD

Fig 26


If false side blind zone alerts occur, inspect the rear bumper fascia for signs of damage. If no fascia damage is found, reprogram the B2181L Side Object Sensor Module. Refer to B2181L Side Object Sensor Module Programming and Setup in the appropriate Service Information.


TIP: Remind owners that if the vehicle is towing a trailer or has an object such as a bicycle rack attached to the rear of the vehicle, the Side Blind Zone Alert system may not function properly and the indicators may illuminate intermittently or remain illuminated all the time.


– Thanks to David Roat

Understanding the Operation of Memory Seats

The available memory seat system on the 2014-2015 CTS Sedan and 2013-2015 ATS provides the convenience of remembering the desired (stored) position of the driver’s seat and outside mirrors, and adjusting the seat and mirrors to that position upon demand. This may be performed manually using the memory buttons or automatically when either the ignition is turned on or when the driver’s door is unlocked and opened with the Remote Keyless Entry (RKE) transmitter (key fob) present.


This information is intended to help you understand the components, features, programming and operation of the memory seat system so you are equipped to help customers who do not fully understand how to use the system.




The memory seat system uses the following components:

• Seat memory control module

• Driver’s memory switches

• Driver’s seat adjuster switches (Fig. 1)

• Four drive motors (horizontal, front vertical, rear vertical and seat recline motors)

• Four motor position sensors (horizontal, front vertical , rear vertical and seat recline motor position sensors)


Additionally, new 2015 ATS Coupe models use the following components:

• – Driver seat easy entry switch

• – Passenger seat adjuster switch

• – Passenger seat easy entry switch

• – Passenger seat horizontal motor


F01 seat controls

Fig 1




The memory seat system performs Memory Seat Recall and Easy Exit functions. These functions can be operated manually or automatically. The automatic recall operation can be enabled by the customer in the vehicle’s Comfort and Convenience menu settings. Automatic recalls can be provided upon Ignition On or Door Open/Unlock.


TIP: If the Door Open/Unlock setting is selected, the driver’s door must also be unlocked for the automatic recall feature to operate.


Easy Entry is available only on coupe models.


The infotainment system reports the automatic memory recall option settings to the seat’s Memory Seat Module as well as other receiving modules via serial data messages. The module stores the memory recall option settings that control its automatic memory recall operations.


TIP: The Memory Seat Module cannot perform the automatic recall functions unless they are activated in the vehicle’s Comfort and Convenience menu settings. If a customer is having trouble getting a feature to operate, first check that the feature is activated in the vehicle menu settings.


Details are found in the Owner’s Manual > Instruments and Controls > Vehicle Personalization > Comfort and Convenience for personalizing the Auto Memory Recall and Easy Exit options. (Fig. 2)


F02 seat menu

Fig 2




The 1, 2, SET, and Exit (door with arrow icon) buttons on the driver’s door (Fig. 3) are used to store and manually recall memory settings for the driver’s seat and outside mirrors.


Once the desired vehicle menu settings are activated, the driver’s seat and outside mirror positions that have previously been stored to the 1, 2 and Exit buttons also can be automatically recalled.


F03 seat memory buttons

Fig 3


To store driver’s seat positions to the 1 or 2 buttons:


1. Adjust the driver’s seat and outside mirrors to the desired driving position.

2. Press and release SET. A beep will sound.

3. Immediately press and hold button 1 until two beeps sound.

4. Repeat Steps 1–3 for a second driver using button 2.


To store positions to the Exit button and Easy Exit features:


• Repeat the steps above, adjusting the driver’s seat and outside mirrors to the desired positions to exit the vehicle, using the Exit button.




Memory recall can be accomplished by pressing and holding or momentarily pressing the desired button, depending on the power mode of the vehicle.


Supervised Memory Recall


If the ignition is Off, or the vehicle is not in Park (automatic transmission) or the parking brake is not set (manual transmission), memory recalls can be initiated by pressing and holding one of the memory position buttons until the seat and mirrors reach the stored memory position associated with the activated button. This is called supervised memory recall.


Releasing button 1, 2, or the Exit button before the stored position is reached stops the recall.


Unsupervised Memory Recall


When the ignition is On and the vehicle is in Park (automatic transmission) or the parking brake is set (manual transmission) a momentary push of a memory recall button moves the seat to the stored memory position associated with the activated button. This is called unsupervised memory recall.


Placing the ignition in the Off/Lock position before the stored position is reached stops the recall.


Easy Entry – (Coupe models only) The seat Easy Entry switches are located in the bezel of the seat back cushion release handle on both the driver’s and front passenger’s seat. Using the Easy Entry switch to move the entire seat forward and rearward is the same as using the seat adjuster switch. (The seat’s forward/rearward movement may be at a faster rate than normal adjustment.)


Although the passenger seat is a non-memory seat, the Easy Entry function is controlled by the seat’s Memory Seat Module.




The Auto (Automatic) Memory Recall feature automatically recalls the current driver’s previously stored 1 or 2 button position when entering the vehicle.


Depending upon the Auto Memory Recall setting enabled in the vehicle menu settings, the 1 or 2 button memory positions are recalled in the following ways:


To activate the recall when the door is opened:

• The ignition must be Off and the setting On – Driver Door Open must be selected in the vehicle personalization menu.

• On vehicles with RKE, press the Unlock button on the RKE transmitter and open the door.

• On vehicles with Keyless Access, press the Lock/Unlock button on the outside driver’s door handle and open the driver door. (Fig. 4) The RKE transmitter must be present for the recall to activate.


If the driver door is already open, press the Unlock button on the RKE transmitter to activate the recall.


F04 seat door handle button

Fig 4


To activate the recall at ignition ON:

• The vehicle must be in Park (automatic transmission) or the parking brake set (manual transmission) and the setting On – At Ignition On must be selected in the vehicle personalization menu.

• Place the ignition in On/Run/Start.


To stop recall movement:

• Press one of the memory, power mirror, or power seat controls.

• If the setting On – At Ignition On is selected in the vehicle personalization menu, placing the ignition in Off also stops the recall.


RKE transmitters are not labeled with a number. If a memory seat position is stored to button 1 or 2 but the position is not automatically recalling, try the other RKE transmitter.




If Easy Exit On feature is selected in the vehicle personalization settings, the Easy Exit feature automatically moves the driver’s seat and outside mirrors to the memory positions stored to the Exit button.


Easy Exit recall automatically activates when the ignition is turned off and the driver’s door is opened within a short time period, or when the ignition is turned off with the driver’s door open.




If something has blocked the driver’s seat while recalling a memory position, the recall may stop. Remove the obstruction. Then do one of the following.


If manually recalling the position – press and hold the appropriate manual control for the memory item that is not recalling for two seconds, and then try recalling again by pressing the appropriate memory button.


If automatically recalling the position – press and hold the appropriate manual control for the memory item that is not recalling for two seconds, and then try recalling again by opening the driver’s door and pressing the Unlock button on the RKE transmitter.


If recalling the Exit position – press and hold the appropriate manual control for the exit feature not recalling for two seconds, and then try recalling the Exit position again.


– Thanks to Jon Nowak, Mark Willey and Elizabeth Hayes



Colorado and Canyon Cargo Box Lighting

The cargo box lighting (RPO UF2) on 2015 Colorado and Canyon models is part of the Center High Mounted Stop Lamp (CHSML) assembly. (Fig. 5) It is standard equipment on all 2015 Colorado and Canyon models.


F05 cargo light

Fig 5


The cab-mounted cargo box light is the only cargo lighting associated with RPO UF2, with all wiring installed at the factory. There is no other cargo box lighting available on the Colorado and Canyon. There is no action or parts needed by the dealership at delivery for the cargo box lighting.


– Thanks to Charles Hensley

Steering Pull at Highway Speeds

On some 2014 Corvettes, the steering may pull to the right while driving at highway speeds. (Fig. 6)


2014 Chevrolet Corvette Stingray convertible

Fig 6


TIP: If the vehicle drives straight ahead without pulling, but the steering wheel is off-angle, refer to the appropriate Service Information for a steering wheel angle condition.


Be sure to document “Before” and “After” wheel alignment measurements whenever an alignment is performed.


Diagnosis should follow these steps:


1) If the pull is minor, but still correctable, verify the condition by lightly holding the steering wheel while driving the vehicle in a straight line at 60-65 mph (97-105 km/h). Document the direction of the pull and rate the condition by describing the amount of pull on a scale of 1–10. Do this evaluation in both left and right sloping lanes as the vehicle will follow the road crown/camber. If the vehicle follows the road crown/camber, this is normal operation and the vehicle is performing to design intent. No repairs are necessary.


2) Do a left to right front wheel/tire assembly swap and evaluate the vehicle again. Document the results. If the pull direction is opposite, refer to the Radial Tire Lead/Pull Correction procedure in the appropriate Service Information to isolate the tire causing the condition. Otherwise, continue to the next step if the pull in the same direction is still present.


3) Put the vehicle on an alignment rack. Record the “Before” measurements and modify the wheel alignment to counteract the pull condition. A vehicle will typically pull to the side with more positive camber. If the vehicle is pulling to the right, increase camber on the left, or decrease camber on the right. Stay within the current wheel alignment specifications in the Service Information. If, after exhausting standard Vehicle Leads/Pulls diagnostics and the above steps, a pull to the right condition still exists, adjust the front cross-camber by up to 1.0 degree. (This is currently outside the specifications noted in the Service Information.) Evaluate the vehicle for pull on both left and right sloping road crown/camber road surfaces.


4) If cross-camber is not causing the right pull condition by being near the negative limit noted in the Service Information and the condition still exists, increase caster on the right and/or decrease caster on the left. Stay within the current wheel alignment specifications in the Service Information. If necessary, use cross-caster down to, or as far negative as, -1.0 degree (which is currently outside the specifications noted in the Service Information). Split the left and right caster about the current nominal caster values in the Service Information by increasing one side of the vehicle by the same amount decreased on the other side. Again, try to remain within the wheel alignment specifications noted in the Service Information. Evaluate the vehicle for pull in both left and right sloping road crown/camber road conditions and verify normal operation. Record the “After” wheel alignment measurements to include with the “Before” measurements in the warranty claim.


– Thanks to Matt Bierlein


Generator and Engine Oil Level Switch Connectors

During reassembly after a heavy engine repair on 2014-2015 ATS, Impala and 2013-2015 Malibu models equipped with the 2.5L engine (RPOs LCV, LKW), it is possible to accidentally install the G13 generator X1 connector (Fig. 7) with the B35 engine oil level switch connector. (Fig. 8) Refer to the appropriate Service Information for connector end views for each specific vehicle.


If the generator and engine oil level switch connectors are improperly installed, the battery, Service Engine Soon or oil level warning lamps may illuminate on the instrument cluster. DTC P0621 (Generator L-Terminal Circuit) also may set in the ECM.


F07 generator connector

Fig 7


F08 oil level connector

Fig 8


Although the connectors are different, they can easily be connected in the wrong location. Confirm or install the connectors in their proper location as needed.


– Thanks to Christopher Crumb

Whine Sound in 4WD Mode

One of the many advantages of the new 2015 Silverado HD 2500/3500 and Sierra HD 2500/3500 is the quiet cabin. For that reason, when the vehicle is in 4WD mode (Hi or Low), there may be a noticeable whine sound from the transfer case.


With the vehicle in 4WD mode, the sound will be present when accelerating (approximately 30-40 mph; 48-64 km/h) and decelerating. It will increase when driving on dry pavement in 4WD. It is not noticeable or is reduced considerably in 2WD mode.


Before beginning any transfer case repairs or diagnosis, review Symptoms – Transfer Case in the appropriate Service Information and perform the necessary inspections. In all cases, the vehicle exhibiting the condition should be compared to another like vehicle before beginning any repairs.


– Thanks to Steve Schipansky

Inoperative HVAC Blower Motor at Start-up

There may be a lack of airflow through the HVAC vents at start-up on some 2014 Silverado 1500, Sierra 1500; 2015 Silverado, Colorado, Sierra, and Canyon trucks equipped with Manual HVAC (RPO C67 or C42). The HVAC controls will be illuminated and the display may show that the A/C is off. (Fig. 9)


F09 4008909 r

Fig 9


Before beginning diagnosis, ask the customer if the following items took place prior to the lack of airflow:


1. Engine is running

2. Blower motor is in any position other than Off

3. Defrost button is selected (indicator light on)

4. Blower motor is turned to the Off position

5. Defrost button is selected (indicator light turns off)

6. Engine is turned off (driver’s door opened and closed to let modules go to sleep after several minutes)

7. Engine is restarted

8. Blower motor knob is turned to any position other than Off and the condition is now present and the blower motor will not adjust the air flow


TIP: Due to EMF operation on the 2015 Colorado and Canyon, the HVAC blower motor has a five second delay on start-up after manually adjusting the power knob from Off to On. It’s important that customers understand that is a normal operating characteristic of the climate control system.


The blower motor function can be restored to proper operation by performing either of the following:


• If any of the HVAC mode buttons are selected and the blower knob is rotated to any position, the blower motor will begin to work properly.

• If the engine is turned off and then restarted and the blower knob is rotated, the blower motor function will be restored.


An updated software calibration has been released to address this condition. Reprogram the K33 HVAC Control Module using the Service Programming System (SPS) with the latest calibrations available on TIS2Web. Refer to the HVAC System Control Module Programming and Setup procedure in the appropriate Service Information.


– Thanks to Jim Will


MagneRide Rear Shocks Not Interchangeable Left to Right

The production rear shocks on 2015 Silverado High Country and Sierra Denali models equipped with MagneRide Magnetic Ride Control (RPO Z95) are not interchangeable left to right.


When performing any service that requires the rear shocks (Fig. 10) to be removed, note their location so each shock can be reinstalled in their original location. The left and right shock each has a slightly different length to help with vehicle assembly during production. If the shocks are swapped left to right, it may cause a harsh ride, the shock bottoming out, metal-to-metal noise, a rattle, and/or damage to the shocks.


F10 shock

Fig 10


TIP: If the rear shocks need to be replaced for any reason, the service replacement shocks can be installed on either the left or right side. Only the production shocks are not interchangeable left to right.


– Thanks to Jim Will

Engine Oil Capacities

Click the chart to view a printable pdf of engine oil capacities for 2014-2015 GM models. Click here for a French version.


F11 engine oil chart

Service Know-How

10214.12D – Emerging Issues

December 11, 2014


To view Emerging Issues seminars:

• Log in to

–   Select Resources > Service Know-How/TECHAssist > Emerging Issues > Searchable Streaming Video; or

–   Select Catalog to search for the course number, and then select View > Take or Continue Course

Service Technical College – New Training Courses

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Bulletin Review – November 2014

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Vehicle Health Management Service Monitors Potential Performance Conditions, Notifies Owners

The new Vehicle Health Management (VHM) service available to owners of a 2015 Equinox or Terrain equipped with the 3.6L V6 engine (RPO LFX) monitors the engine cranking and fuel delivery systems for various performance issues. If an issue is identified, the VHM service sends a message via OnStar® to the Customer Assistance Center (Customer Care Centre in Canada) to contact the owner and help schedule a service appointment. (Fig. 1)


The VHM service is designed as a preventative measure to help owners avoid potential vehicle performance conditions. Owners must enroll in OnStar Vehicle Diagnostics and the VHM service.



Fig 1


The VHM service monitors the engine cranking system — battery and starter performance — and the fuel delivery system — fuel tank fuel pump module and fuel pressure sensor performance — to identify and help prevent various conditions. The VHM service communicates with OnStar only once per ignition cycle.


TIP: Since the VHM service is monitoring the systems for potential conditions, some service messages may be generated without any apparent symptoms being noticed by the driver.


Communicating with Owners


When a VHM service message is triggered, a message is sent via OnStar to the Customer Assistance Center (or Customer Care Centre) to contact the owner and set up a service appointment with the owner’s preferred dealership. The Customer Assistance Center (or Customer Care Centre) also will contact the dealership to assist with the appointment and communication of the VHM service message. The owner and dealership also will receive the service message information by email.


Dealership personnel with any questions about a particular VHM service message received at the dealership should contact the Dealer Business Center (U.S.) or Customer Care Centre (Canada).


Service Message Identifiers


To classify potential issues identified by the VHM service, nine different Service Message Identifiers are used. These are not Diagnostic Trouble Codes (DTC). The identifiers, which combine the related Service Information section with a number, can be used in a Service Information key word search. For example, 12 volt battery is covered under the Starting and Charging section, so the first battery Service Message Identifier is SAC001.


VHM Service Message Identifiers are not stored in the vehicle and cannot be retrieved using a scan tool as would a DTC. Currently, the Service Message Identifiers are only included in the customer communications. Related on-board DTCs may or may not be set.


To begin vehicle diagnosis and repairs, review the Service Message Identifier in the message provided by the owner or the Customer Assistance Center (or Customer Care Centre).


TIP: Due to the unique nature of the VHM service, special Bulletin Only Labor Operations have been set up for repairs of identified service messages. These Bulletin Only Labor Operations must be used for any repairs related to a service message.


Diagnostic Procedures


Following are the Service Message Identifiers for the VHM service. Refer to #PI1250 for complete diagnostic procedures for each identifier.


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TIP: Parts replaced during repairs of identified VHM service messages may be requested to be returned to the Warranty Parts Center.


Once the proper repairs have been made, the VHM service will clear the service message after the vehicle is operated over a number of ignition cycles. If other on-board DTCs have set, clear them prior to releasing the vehicle to the owner.


For additional information about the VHM service, including Labor Operations, refer to #PI1250.


– Thanks to Ray Romeo and Len Tillard

1.2L Engine Piston Installation Tool

When installing the pistons on the 1.2L 4-cylinder engine (RPO LL0) in 2013-2015 Sparks, all piston rings, including the oil expander ring, must be properly positioned prior to clocking or piston, piston ring or cylinder wall damage may result. (Fig. 2)


F02 3999419

Fig 2


Validating the proper ring positioning can be difficult due to the small size. The WISECO RCS07061 ring compressor sleeve (Fig. 3), a commercially available tool for piston installation in this engine, is now available to validate proper piston ring positioning prior to installation, reducing the possibility of damage.


F03 3999432

Fig 3


The WISECO RCS07061 ring compressor sleeve is a cone-style piston installer that will not allow the piston/ring assembly to pass if the piston rings are not properly positioned. The photos show the proper positioning of the oil control expander ring (Fig.4) and an overlapped, improperly positioned oil control expander ring. (Fig. 5)


Once proper ring positioning is established, the piston will install in the cylinder bore with very little effort.


F04 3999428

Fig 4


F05 3999423

Fig 5


– Thanks to Raymond Haglund

Air Cleaner Housing Hydro Carbon Absorber

Some 2013-2015 Encore, Trax (Canada) and 2015 Trax (U.S.) models equipped with the 1.4L 4-cylinder engine (RPO LUV) may have DTCs P0171 (Fuel Trim System Lean) and/or P1101 (Intake Air Flow System Performance) set as current or history DTCs.


If the appropriate Service information diagnostics do not isolate the cause of the condition, inspect the ID code on the air cleaner housing. (Fig. 6)


F06 4006583

Fig 6


The correct application for the 2013-2015 Encore and Trax will have an ID code of ACD and will be fitted with a hydro carbon absorber. (Fig. 7)


F07 4006213

Fig 7


If the hydro carbon absorber is missing, or the ID code is other than ACD, replace the air cleaner housing with the latest listing in the electronic parts catalog.


– Thanks to Raymond Haglund

Engine Block Deck Surface Appearance

During engine block service on some 2011-2015 Cruze, Volt; 2014 ELR; 2013-2015 Encore; 2013-2015 Trax (Canada); 2015 Trax (U.S.); 2012-2015 Sonic; 2004-2012 Aveo; 2005-2009 Wave (Canada); and 2009-2010 G3 models equipped with the 1.4L engine (RPOs LUU, LUJ, LUV), 1.6L engine (RPOs L91, LXV) or 1.8L engine (RPOs LUW, LWE), improper block deck cleaning methods may result in lines in the block deck surface. (Fig. 8) These lines may be mistaken for cracks. (Fig. 9)


F08 4006571

Fig 8


F09 4006573

Fig 9


These lines are the result of using abrasive pad/bristle devices to clean the gasket surface of the engine components. It only takes about 15 seconds to remove 0.203 mm (0.008 in) of metal with an abrasive pad.


TIP: See the latest version of Bulletin #00-06-01-012 for complete details on the use of abrasive devices.


If improper cleaning methods are used, it cannot be determined if the integrity of the sealing surface has been compromised.


The block deck surface lines are not a warrantable condition and should not be claimed as a warranty repair.


Slight traces of these lines seen after using the proper gasket surface cleaning methods will not affect cylinder head gasket sealing.


– Thanks to Raymond Haglund

A/C System Information Needed When Calling TAC

When technical assistance is requested for poor A/C performance conditions on 2015 and prior GM passenger cars and trucks, certain information is helpful for the GM Technical Assistance Center (TAC) in assisting with diagnosing the vehicle.


Before calling the TAC, the following information should be available:

• A/C High and Low pressures

• Outside temperature

• Humidity

• Vent temperature


If the unit is equipped with an Automatic HVAC system, retrieve the following HVAC data with a scan tool:

• Inside temperature sensor reading

• Outside temperature sensor reading

• Duct temperature sensor readings

• Evaporator temperature sensor reading (if equipped)


In addition, callers should always be prepared to provide SI Doc ID(s) or Bulletin/PI numbers when calling the TAC.


– Thanks to Jim Miller



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