Archive for September 2016

Wireless Charging Device Compatibility and Testing

Wireless charging of mobile devices has become a popular option on a number of 2015 and newer GM passenger cars and light-duty trucks. It’s a convenient way for drivers to charge a smartphone without the need for a charging cord.


GM models that may have an optional wireless charging system include 2015-2017 ATS, ATS-V, CTS, CTS-V, Escalade, Tahoe, Suburban, Yukon; 2016-2017 CT6, XTS, Camaro, Cruze, Impala, Malibu, Volt, Silverado, Sierra; and 2017 LaCrosse, XT5, Colorado, and Canyon.


The charging system typically features a charging pad or pocket located on the center console. Here are some examples of charging systems on the Camaro (Fig. 1), Malibu (Fig. 2), CT6 (Fig. 3) and Sierra. (Fig. 4)



Fig. 1



Fig. 2



Fig. 3



Fig. 4


The wireless charging process requires customers to have a compatible phone or a compatible case equipped with an inductive coil. Wireless inductive charging uses an electrically induced magnetic field to transfer energy from the coil in the vehicle’s charging module to the coil in the phone or its case.


Compatible Devices


An increasing number of smartphones have built-in wireless charging technology. Some smartphones require a wireless-capable back cover or adapter. Customers should contact their phone retailer for information about a wireless charging adapter/cover if it’s required for their phone.


The GM Wireless Charging Compatible Devices chart (Fig. 5) has been recently updated. It provides an easy reference of compatible smartphones that feature built-in wireless charging or offer a wireless charging case.



Fig. 5


Charging a Device

1. Verify the phone is properly equipped for wireless charging. 2. Turn on the vehicle or use Retained Accessory Power. 3. Remove all objects from the charging pocket or pad before attempting to charge the phone. Make sure there are not any coins, keys, cards, etc., trapped between the phone and the charging surface. 4. On a charging pad, align the back of the phone (screen facing up) against the flat surface of the charging pad. For a charging pocket, insert the phone (screen facing rearward) into the pocket so the phone screen faces the rubber bumps within the pocket. Proper positioning is critical; the charging coils of the charging surface and the device must line up in order for charging to take place. 5. When the phone is properly aligned, the phone charging icon (lightning bolt) will appear on the infotainment screen and, a few seconds later, the phone’s battery will start charging. If the phone does not charge, remove it from the pocket/pad, rotate it 180 degrees, wait for 3 seconds, and reposition it correctly.


TIP: The Colorado and Canyon do not display the phone charging icon on the infotainment screen. An LED indicator on the console is green when the phone is charging. If the LED is yellow, the phone is not charging and it should be repositioned correctly on the charging pad.


Not all phones will fit properly in all charger integrations. Phones that are longer than 150mm (approximately 6 inches) may have reduced performance or may not charge.


In addition, protective cases used on phones with built-in wireless charging capability may have reduced charging performance.


For vehicles with charging pads, rough roads and vehicle dynamics may result in the phone shifting out of position and charging to stop. If this happens, lift the phone for 3 seconds and place again on the pad with the correct alignment to re-establish charging.


If customers have any questions about wireless charging, direct them to the Owner Center websites for their respective brand.


Testing using the EL-51755 Test Tool


The EL-51755 Inductive Charging Test Tool can be used to verify charging system operation in a vehicle. There is no need to remove the rubber sleeve from the pocket or pad for testing.


When using the test tool with a charging pocket, position the edge of the tool (where the lanyard is attached) approximately 1/4-inch below the lip of the rubber sleeve surrounding the pocket. Keep the tool centered against the front wall to align the coil in the test tool with the coil in the vehicle module.


On a charging pad, align the tool against the alignment rib. For both the pad and pocket, ensure that the flat side (non-LED side) of the tool aligns against the flat charging surface.


To verify the operation of the charging system, simply position the tool on the charging pad or in the charging pocket. If the tool’s wireless charging indicator is on, the charging system is operating properly and any charging concern may be caused by an incompatible or defective mobile device. If the charging indicator is off, continue diagnosis using the appropriate Service Information.


To complete the test successfully, the procedure may need to be repeated 5 times. Between each attempt, remove the tool and wait at least 3 seconds


TIP: For any Mobile Device Wireless Charging System concerns, refer to circuit/system verification and testing in the appropriate Service Information. A scan tool cannot be used since the system is not connected to any control module. No DTCs or data parameters are available.


– Thanks to Deepali Patel, Dan Lascu, Chinmaya Sindgikar, Gurpreet Behniwal, and Manju Bhat



Moving a Vehicle with Electronic Precision Shift and a Dead Battery

The Aisin AF50-8 8-speed automatic transmission (RPO MRC) in the new 2017 XT5 and LaCrosse features the first application of Electronic Precision Shift, which is a shift-by-wire system that enables the transmission range to be selected by electronic control rather than by mechanical means. There is not a physical link, cable or linkage, between the shifter and transmission.


Shifting out of Park


The shift lever has a Shift Interlock button (Fig. 6) on the side of the lever that is designed to prevent inadvertent shifting out of Park. To shift out of Park, the ignition must be on, the brake pedal applied, and the Shift Interlock button pressed. This shift lock control is always functional except in the case of a battery with a low charge (below 9 volts) or no charge.


If the vehicle has a dead battery or a battery with low voltage, charge or jump-start the battery in order to shift out of Park.



Fig. 6


Default to Park


Under specified conditions, including when there is a loss of electrical power or the rear parking brake actuator fails, the Backup Park Lock function, also known as Default to Park, forces the transmission manual shaft to the Park position.


The electronic park brake will not disengage until the condition is corrected. The parking brake can be released manually by removing the rear parking brake actuator and inserting an appropriate hex tool past the splines of the parking brake actuator piston apply spindle in the brake caliper. Rotate the piston apply spindle clockwise to release the parking brake. After repairs, the park brake must be calibrated.


– Thanks to Salvatore Canale

Updated Battery Testing Guidelines

When testing or charging a battery in a vehicle that is in for service or is part of the dealership’s inventory, the EL-50313 Midtronics GR8 Battery Tester/Charger (Fig. 7) should be used in order to provide an accurate diagnosis about the battery’s state of health. Updated guidelines have been released recently in Bulletin #03-06-03-004 outlining the testing process and warranty claims.



Fig. 7

Battery Testing


The EL-50313 Battery Tester/Charger must be used in diagnosing battery replacements and maintaining batteries on new vehicles in dealership inventory. The tool generates a warranty code on a printed slip that captures critical information about the battery’s condition. Warranty codes are only generated when the battery test is set up for Diagnostic Mode and Out of Vehicle. (Fig. 8, #1)


The 15-digit code (Fig. 8, #2) is required for all warranty claims for battery replacement to help in analyzing battery failures and improve product quality. The Warranty Support Center validates all warranty codes entered in the Battery Tester Code field for batteries replaced under warranty. Warranty claims for battery replacements with invalid test codes, incorrect test set-up, or the wrong battery type will not be authorized.



Fig. 8


In addition, the EL-50313 Battery Tester/Charger must be using current software in order to generate a valid warranty code.


On vehicles with two batteries, including Stop/Start vehicles with auxiliary batteries, each battery must be electrically isolated and charged individually, which will result in two printouts.


When testing batteries:

1. Disconnect the battery from the vehicle. 2. Connect the EL-50313 tool cable clamps directly to the battery terminal posts. There is no need to remove the battery from the vehicle. 3. Select “Out of Vehicle” when setting up the test. 4. Select the proper battery type; Flooded, AGM, AUX12. 5. Enter the Cold Cranking Amps (CCA) as shown on the battery label. Refer to Bulletin #15-06-03-002D for 2015–2017 model year battery information.


Tool Software Updates


The EL-50313 Battery Tester/Charger requires periodic software updates. The latest software release is available through GlobalConnect by selecting “Essential Tools – Software Updates” on the Service page.


PDI Mode


When a new vehicle is received at the dealership, the battery must be checked as part of the Pre-Delivery Inspection (PDI). The EL-50313 Battery Tester/Charger has a charge algorithm identified on the tool as PDI Mode. In this mode, the battery condition is checked and then a fast charge is applied to the battery. This mode is designed to apply as much charge as safely possible in 20 minutes.


PDI Mode, which replaces the previous requirement of battery voltage check and charge, generates a printed slip that must be kept with the vehicle file as proof of maintenance. Checking the battery using PDI Mode also must be done at subsequent 30 day intervals while in dealer inventory and at the point of sale.


TIP: Vehicles with Stop/Start auxiliary batteries must be charged separately from the main battery while in dealership inventory storage. The Auxiliary battery is not connected in a manner that will allow both batteries to be charged at the same time, so it must be charged individually, which will result in two printed slips.


Battery Charging


When a battery requires charging, be sure that the ignition is off before connecting or disconnecting the battery cables, the battery charger or the jumper cables. Failure to do so may damage the ECM/PCM or other electronic components.


When charging batteries:

1. Turn off the charger. 2. Ensure the battery terminal connections are clean and tight. 3. Connect the charger positive lead to the battery positive terminal on the battery or the remote jumper stud underhood. 4. Connect the negative charger lead to a solid engine ground or to a ground stud in the engine compartment that is connected directly to the battery negative terminal, but away from the battery. If the negative battery cable is disconnected and a terminal adapter is being used, connect directly to the adapter. Do not connect the negative charger lead to the housing of other vehicle electrical accessories or equipment. The action of the battery charger may damage this equipment. 5. Select ”Charging,” “PDI” and “In Vehicle” when using the EL-50313 Battery Tester/Charger. 6. Select the proper battery type. 7. Enter the CCA as shown on the battery label. Refer to Bulletin #15-06-03-002D for 2015–2017 model year battery information.


– Thanks to Gary McCraw

New Camaro Convertible One-bow Garnish Serviceability Changes

A change has been made in production recently to the 2017 Camaro Convertible one-bow garnish molding. (Fig. 9) This change was phased into Camaro Convertible production in October.



Fig. 9


The original one-bow garnish design (Fig. 10) featured a clip (Fig. 11) on each side to retain the garnish to the top frame.



Fig. 10



Fig. 11


Convertible models now will use a M6 screw (Fig. 12) instead of the clip for better retention on each side of the one-bow garnish.



Fig. 12


The seal retainer will have an access hole to allow for the new screw to pass through.


When servicing the convertible top, determine which design you’re working with. Pull back the weatherstrip around the one-bow garnish to see if it is attached by a clip or the new screw before attempting to remove the one-bow.


Service parts will transition to a one-bow design with a hole milled to allow for the screw. These parts also are compatible with vehicles attached with a clip design and the clip will still be retained in the same location.


– Thanks to Ann Briedis

Sunroof Comfort Stop Position Eliminates Wind Buffeting

The 2017 CT6, XT5 and LaCrosse offer a double-sized power glass sunroof (Fig. 13) with a glass panel over the front row that opens and slides.



Fig. 13


To help eliminate wind buffeting with the sunroof open at moderate speeds, approximately 37–52 mph (60-84 km/h), the sunroof express-opens to a comfort stop position when the Sunroof Slide switch, located on the overhead console, is pressed. The comfort stop position stops the glass panel about 3 inches (76 mm) short of full travel.


To open the sunroof fully, press the Sunroof Slide switch a second time. Wind buffeting will be more noticeable with the sunroof in fully open position.


If customers bring in their vehicle for a wind buffeting concern with the sunroof, be sure to verify the sunroof is in the comfort stop position before performing any additional diagnosis.


– Thanks to Tom Burlingame

New 2017 Corvette Aero Packages

2017 Corvettes equipped with a Performance Package (RPO CFV, CFZ, Z07) have several different aerodynamic components, or ground effects. These packages may include splitters, end caps, rockers, and spoilers that are to be installed on the Corvette during the Pre-Delivery Inspection (PDI) process.


TIP: Aero package components are shipped to dealerships separately. They are no longer shipped inside the vehicle. Refer to Bulletin #16-NA-201 for more information about the special shipping process.


New for 2017, the base Grand Sport and Z06 models (without RPO CFV or CFZ) now include short rocker moldings in addition to a small splitter and short wicker spoiler.


Review the following photos and tables to ensure the correct aero components were shipped to the dealership and are installed on the vehicle during the PDI process.






Small Splitter (Fig. 1)



Fig. 1


Large splitter (Fig. 2)



Fig. 2


End Caps


Short end cap (Fig. 3)



Fig. 3

Tall end cap (Fig. 4)



Fig. 4




Short rocker (Fig. 5)



Fig. 5


Long rocker (Fig. 6)



Fig. 6


Wicker Spoilers


Short wicker spoiler (Fig. 7)



Fig. 7


Tall wicker spoiler (Fig. 8)



Fig. 8



Clear bridge (Fig. 9)



Fig. 9




RPO CFV – Performance Package – Carbon Fiber, Visible

RPO CFZ – Performance Package – Carbon Fiber

RPO Z07 – Performance Package – Z06


Stingray Package (Fig. 10)



Fig. 10


Z51 Package (Fig. 11)



Fig. 11


Grand Sport Package (Fig. 12)


Fig. 12


Z06 Package (Fig. 13)



Fig. 13


For additional information on the Corvette aero packages, refer to Bulletin #16-NA-330.


– Thanks to Jeff Strausser


Properly Remove/Replace Door Handle Key Cylinder Cover to Avoid Damage

Many GM models now feature a driver’s door handle with a cover over the door key cylinder. The cover may become loose, damaged or broken if it is not removed or installed correctly. A loose cover may be hard to detect based on its appearance. (Fig. 14)



Fig. 14


There are four door handle styles that feature covered key cylinders, so the removal and installation procedures are slightly different depending on the door handle.


It may be necessary to remove the door key cylinder cover and use the door key to unlock the door if the vehicle is in Transport Mode, which may deactivate the Remote Keyless Entry (RKE) system on some models, or if the vehicle or RKE transmitter (key fob) has a dead battery.


Before removing the driver’s door key cylinder cover, try to unlock the vehicle using the Passive Entry system (door handle button) or Unlock button on the RKE transmitter. If the door handle button or transmitter button does not unlock the vehicle after several attempts, remove the driver’s door key cylinder cover and use the door key from the RKE transmitter to unlock the vehicle.


TIP: When removing the door key cover, do not use a sharp object, such as a flat-blade screwdriver, that could damage the cover surface. (Fig. 15)



Fig. 15




There are two different door handle styles used on 2014-2017 ATS, CTS; 2016-2017 CT6, XT5, XTS (Fig. 16); 2014-2017 Impala (VIN 1); 2016-2017 Camaro, Malibu (VIN Z); and 2017 Volt and Acadia (VIN N) models. (Fig. 17) These handles use the same key cylinder cover removal and installation procedure.



Fig. 16



Fig. 17


Removing the Cover

1. Pull the driver’s door handle to the open position. (Fig. 18, #1) 2. Insert the door key (Fig. 18, #4) into the slot (Fig. 18, #3) on the bottom of the cover and lift up the key. 3. Move the cover (Fig. 18, #2) rearward and remove it.



Fig. 18


Installing the Cover


While installing the cover, do not push it straight onto the key cylinder base or the retaining tabs could be damaged. (Fig. 19)



Fig. 19


1. Pull the driver’s door handle to the open position. 2. With the cover at an angle, insert the two retaining tabs at the back of the cover between the seal (Fig. 20, #4) and metal base. (Fig. 20, #5)



Fig. 20


3. Slide the cover (Fig. 21, #6) forward to secure the rear tabs (Fig. 21, #7) and press the front of the cover (Fig. 21, #8) to secure it in place. 4. Release the door handle and check that the cover is secured.



Fig. 21


If the cover is loose, the two retaining tabs on the back of the cover may not be seated properly under the metal base. (Fig. 22, correct (left) and incorrect (right) seating) Remove the cover using the door key and install it again, making sure the rear retaining tabs are seated before sliding the cover forward and securing the front retaining tab.



Fig. 22




2015-2017 Escalade models are the only full-size trucks/SUVs that feature a driver’s door handle with a key cylinder cover. (Fig. 23) These models also are shipped from the assembly plant in Transport Mode. However, the RKE system is not affected.



Fig. 23


Removing the Cover


1. Pull the driver’s door handle to the open position. 2. Slide the cover forward and remove it. (Fig. 24)



Fig. 24


Installing the Cover

1. Pull the driver’s door handle to the open position. 2. Position the cover over the key cylinder and slide it rearward. 3. Release the door handle and check that the cover is secured.




The 2016-2017 Envision, Cruze; 2017 LaCrosse and Bolt EV also feature a driver’s door handle with a key cylinder cover. (Fig. 25)



Fig. 25


Removing the Cover

1. Insert the door key into the slot on the bottom of the cover. (Fig. 26) 2. Lift the key upward to remove the cover.



Fig. 26


Installing the Cover 1. Snap the cover onto the retaining tabs. 2. Check that the cover is secured.


– Thanks to Donna Mills

Vehicle Time Out for Parasitic Draw Testing

Many control modules in a vehicle stay awake for different amounts of time after the ignition is turned off. To help with diagnosis of parasitic drains, a Vehicle Time Out chart has been developed for 2015 ATS, ATS-V; 2017 LaCrosse, CT6, CTS, XT5, Corvette, Acadia (VIN N); and 2016 Camaro models listing the times after a specific event that certain modules stay awake. Components most likely to cause a parasitic draw on a vehicle’s battery are switches, relays, and control modules.


The charts lists the amount of time the modules controlling the HVAC, Flashers, Infotainment/DIC, Drive Mode Switch, Park Assist, Headlamps, and Engine Start/Stop features are awake after each of three specific events — door open/close, key fob unlock, and passive unlock.


Refer to Bulletin #16-NA-272 for the chart. It is not a complete listing of all modules that may be active after the ignition is turned off (for example, the interior lights), but includes the most common. Of the modules or switches that are listed, the backlighting or status LED will be on for the time listed.


Powering Down


After the ignition is turned off, the control modules will begin to go to sleep. However, all control modules do not go to sleep at the same time; some may take up to 30 minutes or longer after turning the ignition off before going to sleep. Other modules may periodically wake up and then go back to sleep. It can take up to two hours before all systems power down allowing the parasitic draw test to pass. An occasional increase in the parasitic draw is normal as long as it returns within one second. These are all normal conditions.


There are many things that can prevent a vehicle from completely going to sleep and passing the parasitic draw test. Make sure all the following conditions are met before performing the parasitic current draw test using the EL 38758 parasitic draw test switch. (Fig. 27)

• Ignition off • Key out of the ignition switch – when not equipped with keyless access and start • Retained Accessory Power off – open and close the driver’s door after turning off the ignition • Scan tool not communicating with a vehicle control module – in some cases it may need to be disconnected from the DLC • All access doors closed • Headlamps off – Auto headlamps disabled • Any delay lighting off • Disable any underhood lamp, if equipped • HVAC afterblow off • Any accessory that can work with ignition off is inactive or off • Wait up to two minutes or longer, after all other listed conditions are met



Fig. 27


Some parasitic drains can be difficult to diagnose, especially if other components are causing a module to remain awake. For example, Bulletin #16-NA-126 covers an intermittent dead battery condition on 2016 Cascada models. In this case, if the battery drops below 65% state of charge, the tail lamps send a diagnostic request to the BCM, which causes everything on the BUS to wake up and remain awake until the battery drains. A new tail lamp part number has been released to address this condition.


For additional information on parasitic drains and related conditions, always review the latest bulletins as well as the parasitic drain diagnostics in the appropriate Service Information.


– Thanks to Rob Ritz

Power Brake Booster Replacement

Some 2016 Malibu Limited (VIN 1) models equipped with a 2.5L 4-cylinder engine (RPO LCV) may have an illuminated Check Engine lamp and DTC P050F (Brake Booster Weak Vacuum) may be set.


The vacuum in the brake booster assembly is measured by the brake booster vacuum sensor. The Engine Control Module (ECM) supplies a 5 V reference and a low reference circuit to the brake booster vacuum sensor. The vacuum sensor supplies a voltage signal in relation to the pressure in the brake booster to the ECM.


To address this condition, install a new power vacuum brake booster. (Fig. 28) Do not replace the ECM or power brake booster vacuum sensor.



Fig. 28


– Thanks to Aaron Huston

Loose Spark Plug Wires

Some 2014-2015 Silverado 1500, Suburban, Tahoe, Sierra 1500, Yukon, Corvette; 2015-2017 Escalade; 2016-2017 Camaro and CTS-V models equipped with a 4.3L, 5.3L or 6.2L engine (RPO L83, L86, LT1, LV3) may have an illuminated Check Engine lamp and DTCs P0300 – P0308 (Engine Misfire) may be set. DTCs P0301 – P0308 correspond to cylinders 1 – 8. If these conditions are found, inspect for a loose spark plug wire at the ignition coil.


On the loose spark plug wire, check for a “C” clip on the wire end (Fig. 29, #1) that connects to the ignition coil. Replace the spark plug wire if the “C” clip is missing (Fig. 29, #2) or damaged.



Fig. 29


– Thanks to Richard Renshaw

Active or History DTCs Set in the TCM

There may be several active or history DTCs set in the Transmission Control Module (TCM) on some 2017 ATS, CT6, CTS, Escalade, Camaro, Corvette, Silverado, Suburban, Tahoe, Sierra and Yukon models equipped with the 8L45 transmission (RPO M5T, M5N)) or 8L90 transmission (RPO M5U, M5X). (Fig. 30) The DTCs may include: P0747 (Transmission Control Solenoid Valve 1 Stuck On), P0777 (Transmission Control Solenoid Valve 2 Stuck On), P0797 (Transmission Control Solenoid Valve 3 Stuck On), P2715 (Transmission Control Solenoid Valve 4 Stuck On), and/or P2724 (Transmission Control Solenoid Valve 5 Stuck On).


The Hydra-Matic 8L90 will transfer the power of the high-output

Fig. 30


The transmission control solenoid valves regulate and direct pressurized oil to each of the regulator valves. Each regulator valve then directs pressurized oil to the appropriate clutch assembly to apply the clutch.


If any of the DTCs are set, clear them and drive the vehicle in an effort to have the DTCs set again. If the DTCs do not reset, return the vehicle to the customer. GM Engineering is investigating the setting of these DTCs, which usually set due to a transmission hydraulic or mechanical condition. If the DTCs do reset, follow the appropriate Service Information to diagnose the DTCs.


– Thanks to Terry Neuendorf

Engineering Information Bulletins and Part Restrictions


Service Know-How

10216.10V – Emerging Issues

October 13, 2016


The latest service topics from Brand Quality and Engineering are reviewed, including operation of the hands-free liftgate (Fig. 30) available on several GM models and an overview of the new Electronic Transmission Range Selector.


Fig. 30


To view Emerging Issues seminars:

• Log in to • Select Resources > Video on Demand > GM STC > Search Videos; or • Select Catalog to search for the course number, and then select View > Take or Continue Course

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