New Compressed Natural Gas-Powered. Chevy Express and GMC Savana. GDS 2 Rollout

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1 March Volume 13, No.3 New Compressed Natural Gas-Powered Chevy Express and GMC Savana GM is introducing a dedicated compressed natural gas (CNG) system available on full-size Express and Savana cargo vans for fleet use. The CNG option will be available on 3/4 ton, 135-inch wheelbase and 1 ton, 135-inch wheelbase models. This new CNG option adds to GM s position as an alternative fuels leader. From 1997 to 2007, GM built more than 23,800 CNG or liquefied petroleum gas (LPG) vehicles. Chevrolet and GMC are the only brands to offer a onesource CNG option on vans for fleet customers. CNG 6.0L V8 Engine The CNG vans are equipped with a Vortec 6.0L V8 (RPO LC8). It maintains the same horsepower (323 4,600 continued on page 2 TECHLINEnews Vote on New Quick Links in Technician Poll A new technician poll has been posted on the Service Information forums website. This latest poll asks technicians to offer suggestions and comment on possible quick link pages that may be added in SI. The quick links are a shortcut to specific pages in SI that are frequently used each day, as opposed to having to go through each of the menu selections in order to access the page. Some of the additional quick links that are being considered include: continued on page 2 GDS 2 Rollout The North American rollout of the Global Diagnostic System (GDS) 2 is nearly complete. The updated diagnostic platform and software is required for use with GM Global Architecture (Global A) vehicles. The rollout will conclude with Volt coverage that will be available in mid-march. Additional 2012 model year vehicles will be added as they debut. To use GDS 2 effectively, the dealership infrastructure must meet the required GM guidelines for Techline applications. IT specifications are available at (In Canada, go to Tools and Processes and Equipment in the Service Library on GM GlobalConnect). continued on page 2 Contents New Compressed Natural Gas-Powered Chevrolet Express and GMC Savana Vote on New Quick Links in Technician Poll GDS 2 Rollout Service Bulletin Formats New Water Pump Bolt Torque Sequence...4 Camaro Convertible Top Operation Remote Transmitter Pocket Locations Volt Front Fascia Mounting Points Whine Noise Behind Rear Seats Service Know-How Car Issues Fix It Right the First Time Truck Issues Fix It Right the First Time....9 Customer Care and Aftersales

2 New Compressed Natural Gas-Powered Vans continued from page 1 rpm) and torque (373 4,400 rpm) rating as the 6.0L V8 gasoline engine. Enhancements made to the engine to run on CNG include: Hardened engine components for higher wear resistance and durability required in the gaseous fuel system Exhaust valve materials resist higher temperatures and the corrosive nature of propane and natural gas Intake and exhaust valves feature a special insert that ensures an excellent seal between the valve and valve seat Dedicated gaseous fuel injection and engine control module Engine performance designed to meet Environmental Protection Agency (EPA) and California Air Resources Board (CARB) emission certification requirements Fuel System The CNG fuel system consists of: Four CNG fuel tanks CNG fuel tank pressure relief device (PRD) CNG fill receptacle and fill line CNG fuel tank high pressure lock-off (HPL) solenoid valves CNG fuel tank pressure (FTP) sensor CNG fuel lines Vortec 6.0L V8 (RPO LC8) Four CNG tanks have a 23 GGE capacity. CNG 1/4 turn isolation valve CNG fuel filter CNG high pressure regulator (HPR) The CNG fuel system has four tanks with a 23 gasoline gallon equivalent (GGE) capacity. The first tank (6.4 GGE) is located under the center of the vehicle in place of the regular fuel tank. There are two tanks (4.9 GGE and 4.5 GGE) mounted where the spare tire normally is located at the rear of the vehicle. The fourth tank (7.2 GGE) is mounted on the cargo floor in an enclosure, inboard of the left rear wheelhouse. The fuel storage system provides fuel system corrosion resistance and fuel system integrity that exceed Federal Motor Vehicle Standards. Federal regulations require that the fuel tanks and brackets be inspected every three years or 36,000 miles (60,000 km), whichever occurs first. The service life of the type 1 CNG fuel tanks is 15 years from the date of manufacture, after which, they must be removed from service. There are four externally mounted pressure relief devices (PRD). Two are equipped with a thermally-activated PRD, one with a combination temperature and pressure valve, and one with a pressure operated burst disc. The burst disc activates when CNG tank pressure becomes too high for safe operation (approximately 5,400 psig). TECHLINEnews continued from page 1 Technician Poll Control Module References Table Master Electrical Component List Fastener Tightening Specifications Fluid Capacities After a list of possible quick links has been finalized, technicians will have the ability to vote for their top choices in a future poll. To vote in the poll, go to the SI forums at Click the Forum tab at the top of the page to log in. If you're not a member, simply register for access to the forum. Your input is important. Make your voice heard by voting today. Thanks to Ben Kalman, Chad O'Brien and Dave Nowak GDS 2 Rollout Available GDS 2 training courses include: GDS 2 Overview, D, a video-on-demand course GDS 2, H, an instructor-led training course GDS 2 Certification, H, an instructor-led training course (Canada only) As with GDS currently, a security feature will require users to launch the GDS 2 application from the TIS2Web home screen at least once every seven days. The current version of GDS will no longer be available after March 31,. For additional information about GDS 2, refer to January TechLink. Thanks to Matt Singer continued on page 3 2 March

3 New Compressed Natural Gas-Powered Vans continued from page 2 TIP: All external PRDs are connected to fuel storage pressure and cannot be isolated from the high pressure system. Do not attempt to service these devices or connecting tubing/hoses unless absolutely certain that the system is completely empty of CNG fuel. The CNG fuel lines consist of different fuel line types based on the working pressure and vehicle interface requirements. The high pressure and low pressure CNG fuel lines and hoses are a combination of stainless steel tubing and stainless steel jacketed PTFE (polytetrafluoroethylene). All connections between lines and components are sealed by O-rings specifically designed for CNG operation. The high pressure CNG fuel system is equipped with a manually operated 1/4 turn isolation valve. The valve is located forward of the rear wheel on the driver s side of the vehicle at the inboard side of the LH frame rail. The valve can isolate the high pressure side of the fuel system for some service procedures. If the valve is inadvertently left in the Off position, the vehicle will not operate. The CNG fuel filter, a high pressure coalescing media filter, is located forward of the CNG 1/4 turn isolation valve. It requires periodic service intervals. Fuel flow begins when the ignition is cycled and the high pressure lock-off (HPL) and the high pressure regulator (HPR) solenoids open. The HPR is supplied with fuel at pressures up to 3,600 psig (pound-force per square inch gauge), or 24,821 kpa (kilopascal), at 70 F (21 C). The outlet pressure is regulated to psig and delivered through the low pressure lines to the fuel rail and CNG injectors. HPR assembly A. 1/4 turn isolation valve B. Fuel filter C. High Pressure Regulator The CNG fuel injectors are installed in the base vehicle fuel rail and require spacers between the injector and manifold injector boss. The ECM controls fuel delivery in the same manner as a gas oline vehicle. The CNG fuel system also features the same powertrain diagnostics and use of the Tech 2 scan tool as a gasoline engine. There are not any new DTCs. Follow the standard repair proto col as with a gasoline vehicle. Refer to SI for specific CNG information. TIP: When the fuel supply system needs to be opened, the pressure in the lines must be relieved before attempting repairs. Refer to SI for the low pressure side and high pressure side relief procedures. Refueling With an estimated mpg of 11 city/16 highway, the four tank design with a 23 GGE capacity provides a CNG fill receptacle sealing O-ring range of approximately 250 to 360 miles. The system is designed to be filled at a 3,600 psi (24,800 kpa) station (yellow handle on fill nozzle). It can be filled at a 3,000 psi (20,684 kpa) station (blue handle on fill nozzle), but this will result in a reduced range and a fuel gauge reading of approximately 7/8 full. The CNG fill receptacle is a NGV1 profile and mates to any NGV1 fill dispenser valve. The fill dispenser seals to the receptacle with an O-ring. Replace the O-ring in the fill receptacle before refueling if it is damaged or missing; otherwise, natural gas can leak while refueling. The vehicle is shipped with three replacement O-rings in the storage bin on the engine cover. It should take about 6-8 minutes to fill the fuel tanks at a fuel station for natural gas vehicles. Refueling will stop automatically when the tanks are full. TIP: CNG quantity is affected by changes in fuel temperature and fuel pressure. When refueling in cold ambient conditions, the fuel gauge may not display FULL even though the temperaturecompensated refueling event produces a temperature-compensated FULL condition. This is due to commercial refueling station output regulated by a temperature vs. pressure strategy to prevent the vehicle from becoming over-pressurized if relocated to a warmer ambient location after refueling. Operating Tips The extra hardware needed for the CNG system adds approximately 800 lbs. to the weight of the vehicle. This additional mass reduces the payload capacity. This should be noted when loading the vehicle. Model G23405 (3/4 ton) G33405 (1 ton) Payload 2,409 lbs. 3,374 lbs. Extreme cold weather (below -4 F, -20 C) may make it harder to start the engine. If the vehicle is driven regularly in cold temperatures, it will be necessary to use the standard engine block heater. Routine maintenance schedules (fluids, filters, etc.) for the CNG vans are designed to follow the original specifications for the gasoline-fueled vans. Refer to the Owner Manual for the recommended maintenance service intervals and fluid specifications. Thanks to Chris Graham March 3

4 Service Bulletin Formats General Motors service bulletins are published to keep dealership service personnel up to date on the latest in formation involving vehicle repair and system or component updates. This process has evolved to include a number of content-specific types of communication documents in addition to the traditional service bulletin. The following various types of bulletins are available in the Service Information (SI). Service Bulletins Bulletin Group Service bulletins developed by the Bulletin Group provide specific information directly from GM Engineering and GM Customer Care and Aftersales. These bulletins include: Service Bulletin Information: Information bulletins are used to com - municate additional details or changes to existing Service Information not covered in other types of bulletins. Examples of these include design changes, diagnostic tips, new tools and Owner s Manual Revisions. Sample Number: Service Bulletin Technical: Provides information regarding a specific concern. Contains diagnostic and repair procedures as well as part number and warranty labor operation information. Sample Number: Service Bulletin Warranty: Provides information on revised war ranty claim sub mission procedures, new or revised labor operation information and specific warranty administration procedures. Sample Number: Preliminary Information: These bulletins cover emerging issues which may not yet have a fully defined procedure, labor operation or similar information. These bulletins may evolve into technical bulletins or may be cancelled if the condition is a short term issue that has been resolved. Sample Number: PI0348 Preliminary Information Engineering: These bulletins request real-time information from technicians about a specific vehicle condition. They provide direct contact information for GM engineering and may contain a series of questions or a list of data points to be collected to assist engineering in root cause analysis. To learn more about the PIE process, including technician compensation, refer to the December 2009 TechLink. Sample Number: PIE0141 Service Bulletins TAC Service bulletins also are generated by the Technical Assistance Center (TAC) based on calls received from technicians. These bulletins can be reactive or proactive and may or may not have fully defined procedures, photos or parts information. These bulletins are categorized by vehicle application or component: Preliminary Information Truck Sample Number: PITXXXX Preliminary Information Car Sample Number: PICXXXX Preliminary Information Powertrain Sample Number: PIPXXXX Preliminary Information Performance Parts Sample Number: PPPXXXX Additional bulletins may be generated to address very specific topics; they are not included in the above list. Thanks to Gary Kirrkamm New Water Pump Bolt Torque Sequence A new water pump bolt torque sequence has been implemented on all High Feature V6 engines (2.8L, 3.0L, and 3.6L) to help reduce the potential for water pump gasket leaks. This applies to all model years, 2004 through When installing a water pump, use the following revised water pump bolt torque sequence and procedure: 1. Ensure that the engine front cover and water pump are clear of old gasket material. Tighten the water pump bolts in sequence. 2. Ensure that the water pump mounting bolt holes in the front cover are completely clean and dry. 3. Place a new water pump gasket on the water pump. 4. Place the water pump in position on the front cover. 5. Install the water pump bolts finger tight. 6. Tighten the water pump bolts in sequence to 12 N m (106 lb. in.). 7. Tighten the water pump bolts a second pass in sequence to 12 N m (106 lb. in.). Thanks to Andy Waddell 4 March

5 Camaro Convertible Top Operation folded position. The luggage barrier contains a magnet in the stem that fits into the retainer slot containing the luggage barrier sensor. The luggage barrier sensor is sensitive to the presence or absence of the magnetic field produced by the magnet. To unlock the top from the windshield header, pull and turn the single front latch clockwise. To lock the top when raising it, turn the latch counterclockwise. If the top isn t latched, the trunk will not open. The power switch is located on the left side of the overhead console. Press and hold the rear part of the switch to lower the top and windows. A chime will sound when the top is lowered completely. Press and hold the front part of the switch to raise the top. TIP: The convertible top will not operate in cold weather (32 F, 0 C, or lower) in order to avoid potential damage to convertible top components. Delivering all the performance expected of a Camaro thanks to its enhanced body structure the only thing missing from the Camaro convertible is the hard top. But with the tailored fit and insulated headliner of the power top, the Camaro convertible also provides a comfortable, quiet ride with the top up. The top also incorporates a glass rear window and rear window defogger. Tonneau Cover The optional one-piece, soft tonneau cover fits over the top when lowered, providing a finished appearance. There are a couple of exterior differences on the convertible model, including the location of the AM-FM radio antenna, which is embedded in the rear spoiler on RS-equipped LT and SS models. Also, the trunk lock cylinder is moved from the panel between the tail lamps to an area between the rear seatback cushion and driver s side interior panel. Prior to delivering a convertible equipped with the optional tonneau, two fasteners need to be installed behind the rear seatback, which allow attachment of the front of the tonneau. Power Top Operation The operation of the convertible top is semi-automatic. The user manually latches and unlatches the top while hydraulic power actuation provides the force to raise and lower it. The electrical portion of the power top system consists of a: To install the The optional tonneau requires fasteners, two trim the installation of two fasteners behind panel Christmas the rear seatback. tree fasteners have to be removed. Make sure not to exceed the torque specification in the instructions; otherwise, the panels can be distorted. Folding top control module Header latch position switch Folding top control switch Luggage barrier sensor Folding top position sensor Folding top pump motor To install the tonneau cover with the top down, insert the forward tabs under the trim on each side. Next, attach the cover clips to the fasteners on the rear seatback, and then push the rim of the cover under the vehicle trim. Loss of Vehicle Power The power top can be raised manually if the vehicle has lost battery power. Release pressure on the hydraulic pump by turning the hydraulic pressure release bolt, located under a small cover in the center of the rear seat trim, counterclockwise two full turns using the supplied wrench. This will allow the top to be pulled up and forward. When power is restored to the vehicle, the pressure release bolt must be tightened by turning it clockwise. The luggage barrier must be in the extended, fastened position to operate the top. Training For more information on the operation of the Camaro convertible top, check out TechAssist T, Camaro Convertible Overview and Service Precautions, available through the GM Training website. The power top folds in a simple Z pattern. Before operating the power top, the luggage barrier (or trunk partition) in the trunk must be in the extended, fastened position with no objects above the barrier. The trunk also must be closed. Thanks to Brad Thacher, Gregg Archer and Jerry Rudowyj The luggage barrier is a moveable shade used to divide the trunk into distinct sections, reserving space for the top when in the March 5

6 Remote Transmitter Pocket Locations Vehicles with the Passive Entry Passive Start Option Only The remote transmitter must lay flat in the pocket. If the remote transmitter is attached to a key ring, place the key ring in the indented mold next to the pocket. This will allow the remote transmitter to lay flat in the pocket Place the remote transmitter in the console storage pocket with the buttons facing up. An without removing attached key ring should face the passenger the key ring. If the side of the compartment. remote transmitter will not lay flat with the key ring attached, it will be necessary to remove the key ring. During normal operation or service of vehicles with the Passive Entry Passive Start (PEPS), or push button start, option, it may be necessary to place the remote transmitter (key fob) in the transmitter pocket in the vehicle. TIP: The Volt has a slot that requires key insertion instead of a pocket. Some instances in which the remote transmitter may need to be placed in the transmitter pocket include when: Programming new or existing remote transmitters The No Remote Detected message is displayed on the Driver Information Center A loss of RF communication with the remote transmitter is caused by interference The remote transmitter battery is low Depending on the vehicle, the location of the transmitter pocket varies. Specific remote transmitter placement instructions must be followed to ensure communication is established between the remote transmitter and the vehicle. Cadillac SRX The remote transmitter pocket in the SRX also is located in the center console storage area. Chevrolet Volt The remote transmitter slot in the Volt is located in the upper instrumental panel storage compartment. To properly position the transmitter, remove the rubber mat in the upper instrument panel storage compartment. Extend the key blade on the remote transmitter and insert the blade into the slot. To access the transmitter pocket, open the console storage compartment and lift out the storage tray. Place the transmitter into the transmitter pocket with the buttons facing down. Remove the rubber mat from the upper instrument panel storage compartment for access to the transmitter slot location. The remote transmitter must lay flat in the pocket. If a key ring is attached, place the key ring in the indented mold at the rear of the pocket. This will allow the transmitter to lay Place the transmitter in the pocket flat in the pocket with the buttons facing down. without removing the key ring. If the remote transmitter will not lay flat with the key ring attached, it will be necessary to remove the key ring. Insert the extended key blade into the slot. Buick LaCrosse In the LaCrosse, the remote transmitter pocket is located in the center console storage area. To access the transmitter pocket, remove the cupholder from the center console storage area. Place the transmitter into the transmitter pocket with the buttons facing up. To access the transmitter pocket, remove the storage tray in the console storage compartment. The key ring indentation is at the rear of the pocket. Thanks to Vivian Williams, Michael Gastmeier, Devin Koski, Barbara Leising and Kenneth Strong Remove cup holder from console storage area to access the transmitter pocket. 6 March

7 Volt Front Fascia Mounting Points GM TechLink is a monthly magazine for all GM retail technicians and service consultants providing timely information to help increase know ledge about GM products and improve the performance of the service department. Publisher: Thomas J. Arnold GM Customer Care and Aftersales /Thomas.Arnold@GM.com Editor: Lisa G. Scott GM Customer Care and Aftersales /Lisa.G.Scott@GM.com Technical Editor: Mark Spencer /mspencer@gpworldwide.com Production Manager: Marie Meredith Desktop Publishing: 5by5 Design LLC /dkelly@5by5dzign.com FAX number: Write to: * TechLink PO Box 500 Troy, MI GM TechLink on the Web: : GM GlobalConnect General Motors service tips are intended for use by professional technicians, not a do-it-yourselfer. T hey are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the information applies to your vehicle or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information. Inclusion in this publication is not necessarily an endorsement of the individual or the company. Copyright General Motors All rights reserved. The front fascia of the Volt must be removed to access the BCCM (Battery Charge Control Module) and ECM (Engine Control Module) as well as to service the windshield washer reservoir and one of three radiators. The front fascia features a plastic mounting guide bracket over each front wheel. These two rear mounting points have several tabs that engage the front fascia. Use a plastic nylon wedge between the fascia and the fascia retainer. When disconnecting the fascia at these mounting points, use a plastic nylon wedge between the fascia and the fascia retainer. A high-pitched whine noise may be heard on the Volt if the rear load floor is not properly snapped into place. The noise will be more noticeable during braking or accelerating, mostly in Extended Range mode with the engine running. The noise is coming from the 14-volt power module under the rear load floor. If a high-pitched whine noise is heard from the rear of the vehicle, check that the rear load floor is properly secured. A load floor that is not properly snapped into place will have noticeable gaps between the floor and the vehicle and provide an entry point for noise into the front of the vehicle. Some of the possible causes for the load floor not being properly secured include: An improperly stowed 120V charge cord set Service Know-How D Emerging Issues Broken mounting bracket (top) Insert a small flat-bladed tool into the fascia slot to depress the snaps on the mounting bracket one at a time while gradually pulling on the fascia. When reinstalling the fascia, make sure that the fascia lip is seated rearward of the bracket before attempting to engage the tabs. If the fascia is not outboard, the end of the mounting bracket may break. Thanks to Ashmi Haria Whine Noise Behind Rear Seats The load floor not properly snapped in place. Cargo in the lower tray that may contact the load floor A damaged load floor that does not properly snap into place Thanks to Paul Radzwilowicz March 10, To view Emerging Issues seminars: Log in to 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. March 7

8 Car Issues Fix It Right the First Time Model Year(s) Vehicle Line(s)/Condition Do This Don t Do This Reference Information/Bulletin Cruze Intermittent Malfunction Indicator Lamp (MIL) On, DTC P013B Set Clear code and return car to customer Replace O2 sensor PI All Vehicles Information on Passenger Presence Sensing System (PPS or PSS) Concerns with Custom Upholstery, Accessory Seat Heaters or Other Comfort Enhancing Devices Inform the customer not to modify/degrade the function of the Passenger Presence Sensing system Modify the design of the safety system F DTS, Lucerne Transmission Moan/Whine Noise from Final Drive Carrier Assembly at Low Speeds km/h (15-30 mph) After checking the bulletin breakpoint and doing the road test, replace the final drive internal gear only Replace the transmission or the other final drive components B CTS White Particles Coming from HVAC Air Outlets Replace evaporator & heater cores & cabin air filter and clean evaporator case and all air distribution duct work Replace any parts unless you thoroughly clean the evaporator case and all ductwork PI0346 Cruze Malfunction Indicator Lamp On, DTC P0690 Set Use SI for diagnostics and check ECM software version and update according to PI Do not just reflash ECM unless diagnostics have been performed and version level has been verified PI0347 Cruze, Volt Inspect for Twisted ABS Wheel Speed Sensor During Pre-Delivery Inspection (PDI), ABS Light On, Wheel Speed Sensor DTCs C0035 and C0040 Inspect and replace if Wheel Speed Sensor harness is chafed. Resecure harness without twisting Replace WSS harness if not chafed PI0276A 2010 Malibu Intermittent Illumination of Malfunction Indicator Lamp (MIL)/Check Engine Light, DTC P0172 Set For Code P0172 on LE5 or LE9 engines, follow procedures in this bulletin to diagnose Refer to SI P0172 diagnosis until bulletin procedures are completed A STS Water Spots on Exterior Surfaces Wash using this process and allow to soak a minimum of five minutes to remove water spots Repaint PI0333A DTS, Lucerne Transmission Final Drive Gear Whine Noise at Low Speeds Between km/h (15-30 mph) After checking the bulletin breakpoint and doing the road test, replace the final drive components if necessary Replace the transmission PI0331A CTS Exhaust Noise/Moan/ Drone/Resonance/Vibration at Idle While in Drive with Foot on Brake (Modify Rear Bodyside Exhaust Hanger Brackets) Modify exhaust hanger brackets first and replace muffler assembly with damper if needed Replace muffler unless hanger modification does not resolve concern B LaCrosse Clunk or Scrape Type Noise from Rear of Vehicle Replace left and right rear spring seat insulator with new part number Replace rear coil springs and control arms PI Refer to PI Static Coming from Headphones on Accessory Dual Headrest DVD Systems Perform diagnostics to determine cause of static Replace DVD monitor PI March

9 Truck Issues Fix It Right the First Time Model Year(s) Vehicle Line(s)/Condition Do This Don t Do This Reference Information/Bulletin Escalade, Escalade ESV, Escalade EXT, Avalanche, Silverado LD, Suburban LD, Tahoe, Sierra LD, Sierra Denali, Yukon, Yukon XL LD, Yukon XL Denali-- Squeak/Creak/Rumble or Rattle Noise from Front of Vehicle During Low Speed Maneuvers in Cold Ambient Temps Enlarge upper ID of strut jounce bumper Replace strut, spring, mount, seat, jounce bumper A Sierra, Silverado Brake Pulsation Brake Drag or Vibration Felt in the Steering Wheel Loosen pivot bolt as specified and add locknut Treat just the symptoms with brake pulsation repairs PIT5037B Express, Savana, Sierra, Silverado Low or Speed Limited Diesel Exhaust Fluid Message Displayed Intermittently or Will Not Reset - Including Cold Weather Operation Check and if needed, install revised (double) ECM calibration Overfill DEF tank PIP4864D Sierra, Silverado IPC Warning Lamps and/or MIL, DEF Message Displayed, Various DTCs Set, Transmission May Not Shift or Defaults to Second Gear Ensure any connector TPA is fully seated. Repair and reroute any wiring harness as needed. Repair any connector terminals that are damaged, have poor connections or do not mate properly Replace any control module or wiring harness until you have followed this procedure in its entirety PI Sierra, Silverado One-Piece Hard Tonneau Cover Fits Loose on Vehicle or Rear Tonneau Latch Not Functioning Properly Replace Latch Replace tonneau cover A Express, Savana, Sierra, Silverado MIL Illuminated, Poor Engine Performance with Low Power, DTC P0299, P0513, P0606, P0622, P2202 and/or P22A0 Set Check and if needed, install revised ECM calibration Replace any components Avalanche, Escalade, Escalade ESV, Escalade EXT, Sierra, Silverado, Suburban, Tahoe, Yukon, Yukon Denali, Yukon XL, Yukon XL Denali Inspect XM/Cellular Mobile Phone/OnStar Antenna for Looseness or Damage, Reception Performance Degraded, Rattle Noise, Wind Noise/Whistle, Water Leak on Headliner at Sunvisor Inspect for loose XM/OnStar/Cellular antenna to roof mounting Failure to check for fit could result in water leak damage PI Sierra, Silverado Roll-Up Soft Tonneau Cover Appears Loose or Latch Not Functioning Properly Adjust rails or replace latch Replace tonneau cover A Canyon, Colorado Driver and/or Passenger Front Seat Back Cushion Cover Gapping at Head Restraint Guides If a customer comments of a gapping condition on the driver or passenger front seat back cushion cover at the head restraint guides, add self adhesive foam spacers at the head restraint guide openings. Replace the front seat back cover or cushion PI0344 Customer Care and Aftersales March 9