Archive for February 2014

ELR Smart Wiper System

2014 Cadillac ELR

Fig 1


The 2014 Cadillac ELR features a smart wiper system that includes left and right wiper motor modules instead of the usual single motor and linkage. This is the first GM vehicle with independent wiper motors.


The wiper motor modules are supplied 12 volts B+ at all times through separate fuses in the underhood fuse block. The wiper switch is an input to the Body Control Module (BCM), which commands the wiper motor modules via Local Interconnect Network (LIN) serial data communications instead of wiper motor relay drive outputs. It communicates directly with the left motor module, and that data is passed on to the right module.


Unlike previous wiper systems, each wiper arm operates independently from the other. (Fig. 2) With the ignition off, either arm can be moved to any position on the glass. The left wiper arm also can be raised off the glass and it will hold that position. The right arm can be raised, but will not stay up.


F02 wiper arm

Fig 2


Smart System


The wiper system uses smart motors. The motor module circuitry monitors motor position and reverses power and ground to the motor to reverse wiper direction. It does not use a bell crank.


If the system is allowed to run on dry glass the motors detect the increased friction and the wiper speed will slow to a low pulse rate. As soon as moisture is applied to the glass, the motors will detect the change in resistance and will switch back to the set speed.


If one arm is stuck, such as on ice, the other arm may continue to function. If the system determines that the wipers may contact each other because one blade is stuck, the other wiper also may stop.




Wiper arm alignment is critical for the wipers to operate properly. If an arm is incorrectly aligned or timed, the wipers may collide on the glass, wipe off the glass and over the A pillar, strike the air inlet grill, or not completely wipe the windshield.


There are small transparent alignment circles in the lower center blackout area of the windshield glass that are used for proper alignment. The alignment circle for the right blade (passenger’s side)  is near the center point of the blade and, for the left blade (driver’s side), the alignment circle is near the tip of the blade when the wipers are in the park position. (Fig. 3)


F03 wiper dots

Fig 3


To retime a wiper arm, with the wiper switch and ignition off, begin by removing the wiper arm cap. Use a small flat-blade tool to gently pry up at the small indentation on the rear of the cap to remove it. This provides access to the nut that retains the arm on the motor. While holding the wiper arm, remove the nut.


Use a battery terminal puller to grasp the wiper arm flange and pull the wiper arm from the pivot shaft. (Fig. 4) Do not rock the wiper arm to remove it from the pivot shaft or the motor mounting bracket may be damaged. Clean the pivot shaft with a soft wire brush to remove any debris.


F04 wiper puller

Fig 4


Prior to installing the arm, turn the ignition on and turn the wiper switch to the Low setting. Check that the wiper motor shaft is rotating back and forth, and then turn the wiper switch off. Keep the ignition on. This will command the motor to the park position.


Place the blade on the glass at the alignment circle and then install the arm on the wiper motor shaft by pressing down at the wiper arm knuckle joint. (Fig. 5) Install the nut onto the motor shaft by hand. Recheck blade alignment with the mark on the lower windshield before tightening the nut to specification.


F05 wiper arm install

Fig 5


Test the system to ensure that it is operating correctly in all modes and that the blades properly sweep the windshield. Be sure to reinstall the wiper arm cap.


Wiper Motors


TIP: Before removal or replacement of either wiper motor, the High Voltage Disabling procedure must be performed. High voltage wiring is located next to the wiper motors.


To remove either wiper motor, first remove the wiper arms and then remove the air inlet grill. Each wiper motor is secured with two mounting bracket bolts. (Fig. 6) With the bolts removed, gently pull the motor forward to avoid damaging the windshield or any painted surface. Release the lock tab and disconnect the electrical connector to remove the motor.


F06 wiper bracket bolts

Fig 6


The left and right wiper motors have different internal circuitry and are not interchangeable. Swapping left and right motors will cause both wipers to be inoperative. Each motor and motor bracket has a different part number. All are available as separate parts.


Mounting Brackets


Each wiper motor bracket is part of the Pedestrian Protection package on the ELR.

As part of the safety system, there are two breakaway points on each bracket. (Fig. 7)


F07 wiper bracket break points

Fig 7


TIP: To prevent bracket damage, the wiper arm must be removed with a battery terminal puller and not wiggled off or struck with a hammer. This type of force can cause stress fractures at the breakaway points that may cause the bracket to fail at any time. If the bracket is dropped during service it must be replaced to ensure proper operation.


Before installing the wiper motor, insert the alignment locator on the back of the bracket (Fig. 8) into the retainer on the vehicle. Reattach the electrical connector before carefully sliding the motor into position.


F08 wiper bracket locator

Fig 8


For more information about the ELR wiper system, check out the February 2014 Emerging Issues seminar, 10214.02D (U.S.). In Canada, see the March 2014 TAC Talk program.


– Thanks to Chuck Wieseckel


 Updated Feb. 25, 2014


New Door Latch Design

The door latch design on the 2014 Silverado 1500, Sierra 1500, Impala, CTS Sedan; and 2013-2014 XTS and ATS has changed to a new design that operates slightly differently from the previous common GM design.


On the previous generation door latch (Fig. 9), the closed fork bolt would open when the outside door handle lever was pulled.


F09 latch gen 1

Fig 9


On the new generation door latch (Fig. 10), the closed fork bolt does not open freely when the outside door handle lever is pulled. Force must be applied to release the bolt. This new design provides enhanced sound quality when opening and closing.


F10 latch gen 2

Fig 10


Technicians that close the latch when working on a vehicle stop the door chime from sounding willl need to open the latch manually before closing the door. Do not replace a door latch because the bolt does not spring open.


– Thanks to Keith Borowy



Rear Differential Control Module Reprogramming

The All-Wheel-Drive (AWD) indicator may be illuminated or an AWD Disabled message may be displayed in the Driver Information Center (DIC) on some 2013-2014 Encore and Trax (Canada only) models equipped with AWD.


Code 173 may be set. Code 173 is not a DTC, but an action taken by the Rear Differential Control Module. If any DTCs are set, follow the diagnostics in the appropriate Service Information.


This condition may be caused by the software in the Rear Differential Control Module (RDCM). Updated Rear Differential Control Module software is being developed to address this condition. If Code 173 is observed, It’s necessary to reprogram the Rear Differential Control Module. The updated calibration will be available in TIS2Web soon.


– Thanks to Bob Kerzka


Updated March 24, 2014


Brake Noise on Initial Brake Apply

An intermittent brake squeal or squeak noise on the initial brake apply may be heard on some 2013-2014 Regal GS, ATS (equipped with RPO J55), XTS (equipped with RPO J64); 2014 CTS Sedan (equipped with RPO J55 or J56), Corvette, and SS models.


The squeal or squeak noise from the front brakes or rear brakes (Corvette only) usually only occurs on initial brake applications after the vehicle has sat for an extended time. The condition occurs under light braking in speeds under 10 mph (16 km/h). After 1-6 brake applies, or after braking at higher speeds, the noise no longer occurs. In addition, this condition may occur more often in high humidity conditions.


TIP: Do not apply lubricant to the back of the backing plate.


Apply a light coat of lubricant, part number 19303310 (In Canada, part number 19303311) to completely cover the front or rear disc brake pad backing plate abutments on each end. (Fig. 11) The lubricant should not extend onto the friction material.


F11 pad

Fig 11


– Thanks to Mark Gordon

No Fob Detected Message

A No Fob Detected message may be displayed on the Driver Information Center of some 2004-2009 XLR and 2005-2013 Corvette models when attempting to start the vehicle. The engine may not crank/start and the vehicle’s doors may not open through passive entry. However, the vehicle will always start when the Remote Keyless Entry transmitter (key fob) is placed in the instrument panel compartment pocket. This condition may be caused by an internal transistor of the Remote Control Door Lock Receiver (RCDLR) module not operating properly.


To diagnose this condition, be sure the vehicle battery is adequately charged to start vehicle.


Next, remove the battery from the key fob. Using a DVOM, measure the voltage.  Be sure the key fob battery voltage is between 2 to 3 volts. If not, replace the battery. Test operation of the vehicle again. If the vehicle no longer exhibits the condition, the vehicle is repaired.


If the vehicle has a known good key fob (not placed in the instrument panel compartment pocket), press the Engine Start Button and listen for a click noise or a series of click noises from the RCDLR. If there is only one click (instead of a series of clicks), the transistor internal to the RCDLR is not operating properly. For this condition, replace the RCDLR module.


The RCDLR module on the Corvette is located above the radio behind the instrument panel trim on the right side. (Fig. 12) On the XLR, the RCDLR module is located on the top right of the instrument panel under the upper instrument panel pad. (Fig. 13)



Fig 12


Fig 13


– Thanks to Matt Bierlein


Extended Cold Crank with Direct Injected Engines

The 4.3L, 5.3L, and 6.2L (RPOs LV3, L83, L86 and LT1) direct injected (DI) engines (Fig. 14) available on some 2014-2015 Corvette, Silverado 1500, Suburban, Tahoe, Sierra 1500 and Yukon models may have an extended or long crank time during cold ambient air temperatures.


2014 "LT-1" 6.2L V-8 VVT DI (LT1)

Fig 14


Direct Injection engines may have slightly longer cold crank times than that of port fuel injected engines. Direct Injection systems run at higher pressures and the mechanical pump on the engine must build up the required pressure before the first injection event occurs.


Following are typical DI engine crank times using gasoline:


Screen Shot 2014-02-20 at 11.22.51 AM


If the temperature is below -22°F (-30°C), the recommendation is to perform an assisted start (such as with the use of a block heater).


For ethanol fuel, see #PIP5174: Extended Engine Crank Times When Using E85


– Thanks to Richard Renshaw

Additional Information on Bleeding the Brakes

Several additional steps are needed to perform a successful brake bleed on the 2011-2014 Volt and 2014 ELR.


The braking system on these models is unlike most traditional hydraulic brake systems. It is very important to follow the brake bleeding procedure exactly. Air trapped in the brake system will cause performance problems and DTCs without the symptoms of a spongy or low brake pedal.


If a step is missed in the brake bleed procedure, the procedure must be started over at step 1 without exception.


Follow these guidelines when bleeding the brake:


• Install a battery charger on the vehicle to maintain battery voltage.


• Use a pressure bleeder, such as tool J-29532-B (Fig. 15), that is capable of delivering 30 psi for the entire bleed procedure. Failure to provide a constant 30 psi will cause air to be trapped in the brake system and may cause brake performance problems or DTCs to occur. Vacuum bleeding and other brake bleeding tools are NOT acceptable for this procedure.


TIP: The dealership must use a J-29532-B pressure bleeder or a diaphragm type (ball bleeder) pressure bleeder along with the J-35589-A Brake Pressure Bleeder Adapter in order to perform the hybrid brake system bleed procedure.

A replacement J-29532-B can be ordered from 1-800-GM-TOOLS (1-800-468-6657). Select option #3 for tool ordering.


• Do not attempt to use the manual bleed procedure as this will not properly bleed all the air from the system.


F15 J29532-A

Fig 15


– Thanks to Paul Radzwilowicz


Updated February 27, 2014

No Start Due to Improperly Installed Accessories

On some 2008-2014 Enclave, 2009-2014 Traverse, 2007-2014 Acadia, and 2007-2010 Saturn Outlook models, the Service Engine Soon (SES) light may illuminate or the battery may drain overnight. During diagnosis, a 4.1 amp draw on the electrical system may be found. The draw may be steady or may drop down to a low milliamp reading for 1-2 seconds and then rise back up near 4.1 amps.


This condition may be caused by non-GM Accessories aftermarket products or an improperly installed GM Accessories product that is wired into circuit 1732 for the courtesy lamps. If an aftermarket accessory is installed into the courtesy lamps circuit, the inadvertent power timer in the Body Control Module (BCM) may continuously reset. If this occurs, the BCM may remain awake and cause excessive battery drain.


When servicing a vehicle with this condition, back out pin 1 of connector 2 at the BCM (Fig. 16) and check if the draw goes away. If the draw goes away, check for an aftermarket accessory (such as a security system, non-factory DVD system, alarm, etc.) that is improperly wired into circuit 1732.


F16 pin 1

Fig 16


– Thanks to James Miller

Schematics RPO Code List

Beginning with the 2013 model year, the schematics in the Service Information changed from a TIF graphic format to a CGM graphic format. The new format offers additional information through the use of hotspots, links and larger illustrations. The CGM graphics are available when viewing many schematics, component views, harness routing views and other information in the Power and Signal Distribution electrical sections.


Each type of schematic has some level of related information, including:

• Connector End Views

• Component Locator Views

• Harness Routing Views

• Electrical Center Identification Views

• Master Electrical Component List

• Master Electrical Schematic Icons

• Schematics Regular Production Option (RPO) Code List

• Circuit Number/Wire Colors

• Wire Lines

• Connector Cavities


New RPO List


With the change to a CGM graphic format, the Schematics RPO Code List was introduced. (Fig. 1) This table lists all RPOs referenced in the schematics and provides a description of the RPO and country usage. The table is designed to clearly identify the different drawing schematics for multiple markets within a given Service Information publication since some of the RPOs in the schematics information will not being available in all markets.


F01 RPO schematics list

Fig 1


The main RPO Code List (Fig. 2) found under General Information in the Service Information is not the same as the Schematics RPO code list. The mechanical RPO list covers all options available on the vehicle, but does not identify RPOs used in other regions as does the Schematic RPO list.


F02 RPO gen info list copy

Fig 2




To view the description of an RPO listed on a schematic, mouse-over the RPO and the description will display.


The schematic also has hotspot links to additional information. Here’s an example.


On the 2014 Malibu, mouse-over the E4RR turn signal lamp in the G405 Ground Distribution Schematic to view links (Fig. 3) to the following information:

• The LED Tail Lamps (RPO 1LZ) component description

• Rear of Vehicle Components (Fig. 4)

• E4RR Turn Signal Lamp connector part information and terminal part information


F03 RPO link

Fig 3


F04 RPO component desc

Fig 4


In addition, other links in the upper right corner on the schematic provide the Master Electrical Component list (Fig. 5, A), the Control Module References list (Fig. 5, B), and the Description and Operation, if applicable.


F05 RPO other links

Fig 5


– Thanks to Lou Winters


New Pinion Nut on 9.5/9.76 Inch Rear Axle

The 2014-2015 Silverado and Sierra equipped with the 9.5/9.76 inch rear axle uses a different pinion nut than the axle on previous models. The pinion nut does not have a washer between the prevailing torque nut and the pinion flange like the previous style. (Fig. 6) Instead of a prevailing torque nut, the new style nut (Fig. 7) is staked in place after installation into a staking groove in the pinion. Do not add a washer under the nut on these applications.


F07 nut old styleFig 6


F06 nut new styleFig 7


TIP: Prior to disassembly, observe and mark the positions of all the driveline components, relative to the propeller shaft and the axles, including the propeller shafts, drive axles, pinion flanges, output shafts, etc. Reassemble all the components in the exact places in which the parts were removed. Follow any specifications, torque values, and any measurements made prior to disassembly.


When removing the new 9.5/9.76 inch rear axle pinion nut, it may require increased effort to break the nut staking loose before the nut can be easily removed. Use the J-8614–01 holder and remover to remove and discard the pinion nut. Do not reuse the pinion nut. Replace it with a new nut.


When installing the new pinion nut on the 9.5/9.76 inch rear axle, use a hammer and punch to stake two sides of the drive pinion nut lip to the corresponding grooves in the drive pinion gear. Take care to not split the nut lip, which could affect nut torque retention. If the nut lip is split, use a new nut.


During rear axle diagnosis, check for wear on all components. Ring and pinion gears are matched sets. When replacement of one or the other is necessary, both the ring and pinion gear must be replaced.


• Check the pinion and ring gear teeth for cracking, chipping, scoring, or excessive wear.

• Check the pinion gear splines for wear.

• Check the pinion flange/yoke splines for wear.

• Check the fit of the pinion gear splines on the pinion flange/yoke.

• Check the sealing surface of the pinion flange/yoke for nicks, burrs or rough tool marks that could damage the seal and cause an oil leak.

• Check for worn or broken parts and replace as necessary.



– Thanks to David MacGillis


Tire Cold Weather Cracking

Cold weather, and there has been a lot of it across the country recently, can affect a vehicle’s performance in many ways. A recent TechLink article [add link to] covered how the different compounds of various winter, summer and all-season tires can result in varying degrees of tire noise.


In addition, the special tread and compounds used on high performance summer-only tires can cause a decrease in performance and reduced traction in cold climates with temperatures below approximately 40°F (5°C). GM recommends installing winter tires if driving below these temperatures.


Cold temperatures also may cause actual tire damage on some high performance summer-only tires if temperatures drop below 20°F (−7°C). GM recommends avoiding operating affected vehicles when equipped with high performance summer-only tires at these temperatures.


The following vehicles are all equipped with 3-season performance tires commonly referred to as summer tires.


Screen Shot 2014-03-05 at 2.03.45 PM


At colder temperatures, the rubber used in these tires loses flexibility and may develop surface cracks in the tire tread/shoulder area. (Fig. 8) Surface cracks are cosmetic and will not result in a loss of air. However, the cracking is damaging to the tire. Tires that have been used in cold climates and exhibit tread cracks should be discarded.


F08 crack r

Fig 8

Tire Storage


Summer tires should be stored indoors at temperatures above 20°F (-7°C) when not in use. If the tires have been subjected to 20°F (-7°C) or less, let them warm up in a heated space to at least 40°F (5°C) for 24 hours or more before being installed or driving a vehicle on which they have been installed. Inflate the tires only after they have been warmed above 40°F (5°C).


Do not place tires near heaters or heating devices used to warm the room where the tires are stored. Do not apply heat or blow heated air directly on the tires. Always inspect tires before use after being stored.


Refer to the latest version of Bulletin #04-03-10-013 for information on available winter tires for cold climate operation or call the GM Tire Program at 1-877-728-4737 (U.S. only) for help with late season tire availability or substitutions.


– Thanks to David MacGillis


Updated March 5, 2014


Passive Door Locking Does Not Function

On some 2013 Malibu models equipped with the Passive Entry System (RPO ATH) that were built prior to January 1, 2013, the passive door locking feature may not function when the vehicle is exited even though the system has been enabled by the owner.


A new calibration has been released for the Body Control Module (BCM) to enable the feature. Using SPS, reprogram the BCM with the latest calibration available in TIS2Web.


After programming, verify the Passive Lock feature is activated by performing the following procedure (also covered in the Vehicle Personalization section of the appropriate Service Information):


1. Press CONFIG, and then select Vehicle Settings to access the personalization menu.

2. Select the Remote Lock, Unlock, Start menu item. (Fig. 9)

3. Turn the Tune/Menu knob to highlight Passive Door Lock.

4. Press the Tune/Menu knob to select Passive Door Locking.

5. Turn the Tune/Menu knob to highlight Off, On, or On with Active Horn Chirp.

6. Press the Tune/Menu knob to select the setting and return to the last menu.


F09 setting

Fig 9


Confirm the feature is functioning by turning the vehicle off, removing the key fob from the vehicle, and closing all doors.


The vehicle doors should lock eight seconds after moving the key fob away from the vehicle.


– Thanks to Christopher Crumb


Do Not Swap Control Modules

On GM models with the Global A electrical architecture, a no start condition or another concern may appear after swapping an Engine Control Module (ECM) or other modules from one vehicle to another.


Current models using the Global A electrical architecture include:



• 2010-2015 LaCrosse

• 2011-2015 Regal

• 2012-2015 Verano

• 2013-2015 Encore



• 2010-2015 SRX

• 2013-2015 ATS, XTS

• 2014-2015 CTS Sedan, ELR

• 2015 Cadillac Escalade Models



• 2010-2015 Camaro, Equinox

• 2011-2015 Cruze

• 2012-2015 Sonic, Volt

• 2013-2015 Spark, Trax (Canada only), Malibu

• 2014 Silverado 1500, Spark BEV

• 2014-2015 Caprice PPV, Corvette, Impala, SS

• 2015 Colorado, Silverado, Suburban, Tahoe



• 2010-2015 Terrain

• 2014 Sierra 1500

• 2015 Canyon, Sierra, Yukon Models



The Global A electrical architecture associated with these vehicles does not allow controller swaps between vehicles. Swapping ECMs or other modules, including Radio, Body Control Module (BCM), Electronic Brake Control Module (EBCM), Sensing Diagnostic Module (SDM), Transmission Control Module (TCM), Electronic Climate Control (ECC) (HVAC), Electronic Power Steering (EPS), Hybrid Powertrain Control Module (HPCM), and the Instrument Panel Cluster (IPC), between two vehicles with the Global A electrical architecture will result in damaging both controllers.


TIP: A NO START CONDITION WILL OCCUR ON BOTH VEHICLES IF THESE MODULES ARE SWAPPED due to the new vehicle security code protocol (environment) implemented with the 2010 model year Global Diagnostic System (GDS) applications.


– Thanks to Ernest Haller




New DOT 3 Brake Fluid

There is a new DOT 3 brake fluid available for 2015 Escalade Models, Silverado, Suburban, Tahoe, Sierra, and Yukon Models; and 2014 Silverado 1500 and Sierra 1500.


The new fluid has significant improvements in lubricity to eliminate previously known issues with master cylinder squeak/noise.


The new DOT 3 brake fluid — GM P/N 19299818 (U.S.) and GM P/N 19299819 (Canada) — is available for order through the dealership parts department.


Always use the new DOT 3 brake fluid when refilling or servicing the brake system. If another type of DOT 3 brake fluid (including the GM DOT 3 Delco Supreme II) is used to refill the master cylinder, it may cause a master cylinder squeak noise. If the wrong DOT 3 brake fluid is used, remove as much of the old brake fluid from the master cylinder as possible and refill with the new DOT 3 brake fluid. Depress and release the brake pedal five times to allow the new fluid to enter the system.


– Thanks to James Will

Daytime Running Lamps Operation

On 2014 Camaro models equipped with High Intensity Discharge (HID) headlamps, the Daytime Running Lamp (DRL) (Fig. 10) will turn off when the turn signal is turned on. For example, when the left turn signal is turned on, the left DRL will turn off.


2014 Chevrolet Camaro SS convertible

Fig 10


This is normal operation for this lighting system. No repairs should be made. This is a design characteristic due to the close proximity of the Daytime Running Lamps to the turn signals, which may make it harder to see the illumination of the turn signal during bright daylight conditions.


– Thanks to Matt Bierlein

Moving Vehicles to/from U.S. and Canada

Customers who are permanently relocating from the United States to Canada or from Canada to the U.S. may seek to make modifications to their vehicle in order to comply with U.S. or Canadian requirements, including emissions, lighting and other equipment.


General Motors (GM) and General Motors of Canada Ltd. (GMCL) do not support cross border sales. Dealerships are not authorized under their agreements with GM or GMCL to sell new vehicles for export. Customers living in one country but moving to another should contact the GM Customer Assistance Center (CAC) for information on warranty coverage.


While GM make no claims about the accuracy of the information, the following websites may be helpful in providing information regarding the importation of vehicles into Canada and the U.S., including the legal requirements for modifications to such vehicles. The Registrar of Imported Vehicles (RIV) created by Transport Canada (Fig. 11) . The National Highway Traffic Safety Administration


F11 RIV webFig 11


– Thanks to Matt Bierlein

Service Know-How

10214.02D – Emerging Issues

February 13, 2014


To view Emerging Issues seminars:

• Log in to

–   Select Resources, and then Video on Demand; or

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


Car Issues – Fix It Right the First Time

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Truck Issues – Fix It Right the First Time

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