Archive for September 2015

2016 CTS-V Builds on its Legacy

The 2016 Cadillac CTS-V (Fig. 1) builds on the V-Series legacy, combining a luxury sedan with performance capabilities that make it the most capable V-Series ever. With its supercharged 6.2L V8 engine, paddle-shift 8-speed automatic transmission featuring launch control and Performance Algorithm Shifting, the CTS-V is capable of 0-60 mph (0-100 km/h) performance in 3.7 seconds and a top speed of 200 mph (322 km/h).


2016 Cadillac CTS-V Sedan

Fig. 1


Designed to Perform


The CTS-V is designed to perform on the track or the open road. Inside the cabin, it features an interior with high-performance seats and ergonomics that put the focus on driving.


Outside, the sleek exterior design features a standard carbon fiber hood and an available carbon fiber package that includes a carbon fiber splitter, hood vent, rear spoiler and rear diffuser for greater aerodynamic performance.


Supercharged Engine


The all-new supercharged 6.2L V8 engine (RPO LT4) has a power output of 640 horsepower and 630 lb.-ft. of torque. (Fig. 2) The lubrication system includes eight underside oil-spray squirters. Each one sprays oil on the underside of a piston and the surrounding cylinder wall to help reduce piston temperature and dampen noise.


2016 "LT4" 6.2L V-8 AFM VVT DI SC (LT4) for Cadillac CTS-V

Fig. 2


The compact 1.7L supercharger increases the air pressure and density in the intake manifold to a maximum pressure boost of 9.7 psi (66.9 kPa). The boost pressure is controlled using a bypass valve. The supercharger’s rotors are smaller in diameter than the previous supercharged engine, allowing higher maximum RPM and quicker “spin up” that enables power-enhancing boost to be generated earlier in the RPM band. The engine uses two intercoolers, one for each cylinder bank, that are integrated into the lower intake manifold.


A capless fuel system is used on the CTS-V. When fueling the vehicle, insert the fuel nozzle slowly and wait for any hiss noise to stop prior to starting to add fuel. The fuel nozzle must be fully inserted and latched. After initial fuel pump shutoff, do not partially remove the nozzle to add more fuel.


TIP: Overfilling the fuel tank by more than three clicks of a standard fuel nozzle may cause vehicle performance issues, including engine stalling and damage to the fuel system as well as fuel spills.


8-Speed Automatic Transmission


The Hydra-Matic™ 8L90 8-speed automatic transmission (RPO M5U) uses five clutches to direct power flow through the transmission. There are no sprags or roller clutches. Each gear range has three clutches applied. During shifts, the Transmission Control Module (TCM) commands one clutch off and applies a different clutch. The clutch control solenoids control the application and release of the clutches.


The paddle shift features a temporary tap mode and a permanent tap mode. The temporary tap mode is used while the transmission is in Drive. Either paddle behind the steering wheel (Fig. 3) can be used to temporarily take control of gear selection. If no shifts are made after 10 seconds, automatic shifting returns. The permanent tap mode is used with the transmission in Manual mode. The paddles are used to upshift or downshift.


2016 Cadillac CTS-V Sedan

Fig. 3


Brakes and Suspension


A Brembo high-performance brake system provides durability, consistency and capability for track-day performance. The system includes Ferritic Nitrocarburizing (FNC) rotors for corrosion resistance. The vented and directional front rotors are 15.35-inch diameter (390 mm) x 1.41- inch (36 mm) with staggered six-piston calipers and the vented rear rotors are 14.37-inch-diameter (365 mm) x 1.10-inch (28 mm) with four-piston calipers.


The CTS-V also features the third-generation Magnetic Ride Control system and Performance Traction Management. Magnetic Ride Control “reads” the road a thousand times per second, sending data to magneto-rheological fluid-filled dampers that can independently control the damping characteristics of all four dampers. There are three driver-selectable Magnetic Ride Control modes: Touring, Sport, and Track.


There are also four Driver Mode Controls available: Tour, Sport, Track, and Snow/Ice. Track mode provides maximum vehicle handling and offers five Performance Traction Management (PTM) Modes. The Mode button and Traction Control button on the center console enables drivers to select the Driver Modes and PTM Modes.




The Performance Data Recorder, controlled through the Cadillac CUE touch screen, allows drivers to record high-definition video, with data overlays, of their driving experiences on and off the track. It has four different displays: No Overlay, Sport, Track, and Performance Timing. (Fig. 4) The HD video is from the frontview camera mounted in front of the inside rearview mirror and is recorded on an SD card located in the glove box. Playback is available only when the vehicle is parked.



Fig. 4


Cadillac CUE enhancements include phone integration capability with Apple CarPlay™ and Android Auto™ capability (late availability).


In addition, the wireless inductive charging system for smartphones, compatible with Powermat and other in-phone wireless charging technologies, allows drives to wirelessly charge their mobile device. To charge a compatible device using the wireless inductive charging system, the device is simply placed face up on the charging pad behind the climate controls panel.


Refer to #PI1529 for additional information. To enroll in the available training courses on the CTS-V systems, go to (U.S) or, in Canada, go to GM GlobalConnect and select Centre of Learning.


To get a sense of the CTS-V’s capabilities on the track, click the video below.


F04A CTSV track


– Thanks to Sherman Dixon and Carrie Harvey

2016 ATS-V is Ready for the Track

The 2016 Cadillac ATS-V (Fig. 5) is a track performer wrapped in a compact luxury package. Available as a coupe or sedan, it has the first-ever twin-turbocharged engine in a V-Series model along with many other features designed to increase its performance metrics. The lightweight carbon fiber hood, for example, features an air-extracting vent that pulls hot air out of the engine compartment while also helping to reduce lift at speed by channeling air pulled through the radiator out and over the top of the car rather than allowing trapped air to exit under the car.


2016 Cadillac ATS-V Sedan

Fig. 5


Twin Turbos


Rated at 464 horsepower and 445 lb.-ft. of torque, the twin turbocharged 3.6L V6 engine (RPO LF4) is the segment’s highest-output six-cylinder. It’s available with a 6-speed manual transmission with Active Rev Match, no-lift shifting and launch control or a paddle-shift 8-speed automatic transmission featuring launch control and Performance Algorithm Shift. A standard electronic limited-slip differential (eLSD) supports optimal traction and enables maximum corner exit acceleration.


Exclusive features for the ATS-V version of the twin turbocharged V6 engine include:

• Cylinder heads with sodium-filled exhaust valves with hardened seats and integrated exhaust manifolds

• An engine-mounted mechanical vacuum pump that ensures sufficient vacuum to control the turbochargers

• Lightweight titanium connecting rods that reduce inertia of the rotating assembly, complementing the quick-spooling turbochargers

• Cast aluminum pistons with a polymer coating

• A high-performance wet sump oil pan lubrication system, designed to maintain optimal oil pressure and ventilation during high-lateral driving maneuvers typically encountered on a track


TIP: The twin turbocharged 3.6L V6 engine has a front and rear Mass Airflow Sensor with Intake Air Temperature Sensor.


The charge air cooling intercooler uses two air-to-liquid coolers. The cooling air intakes are mounted on the lower sides of the front fascia in front of the tires. (Fig. 6) The intercooler combines air flow from both turbochargers and directs it to a single throttle body and reduces temperature by more than 130°F (54°C) at peak power.


F06 ATSV intercooler

Fig. 6


The twin turbochargers have low-inertia titanium-aluminide turbines and vacuum-actuated wastegates for more responsive torque production. Compressors are matched for peak efficiency at peak power levels, for optimal track performance.


8-Speed Automatic Transmission


The Hydra-Matic™ 8L90 8-speed automatic transmission (RPO M5U) uses five clutches to direct power flow through the transmission. Each gear range has three clutches applied. During shifts, the Transmission Control Module (TCM) commands one clutch off and applies a different clutch. The clutch control solenoids control the application and release of the clutches.


The Internal Mode Switch detects the angular position of the shift selector shaft and is used by the TCM to indicate the transmission gear selector lever position. This information is used for engine controls as well as determining the transmission shift patterns. The state of each input can be displayed on the scan tool.


The transmission has a fluid pump mounted to the valve body. With the fluid pump moved off the input shaft, the length of the transmission stays similar to the 6L80 and 6L90 transmissions.


6-Speed Manual Transmission


The Tremec TR6060 6-speed manual transmission (RPO MG9) is a fully synchronized manual transmission with an enhanced synchronizer cone arrangement. An internal fluid pump circulates lubricating fluid to the transmission fluid cooler, which is part of the radiator.


The Active Rev Matching of the manual transmission matches engine speed to road speed for the next gear for precise shifts. It’s controlled using the paddles behind the steering wheel. (Fig. 7) Amber gear numbers on the instrument cluster indicate Active Rev Matching is active. White numbers mean the system is not activated.


2016 Cadillac ATS-V Sedan

Fig. 7


Brakes and Suspension


The Brembo high-performance brake system includes vented Ferritic Nitrocarburizing (FNC) brake rotors, with 14.5-inch-diameter (370 mm) front rotors with staggered six-piston calipers (Fig. 8) and 13.3-inch-diameter (339 mm) rear rotors with four-piston calipers.


TIP: The front disc brake rotors are directional rotors and are not replaceable right side to left side.


2016 Cadillac ATS-V Sedan

Fig. 8


The high performance pads may generate a noticeable amount of brake dust. This is normal wear dust from the pads. The wheels can be cleaned using a soft cloth with mild soap and water. Rinse thoroughly and apply wax on the wheels to reduce the amount of accumulated dust.


The ATS-V also features third-generation Magnetic Ride Control and Performance Traction Management. Magnetic Ride Control “reads” the road a thousand times per second and uses that data to instantly adjust the magneto-rheological fluid-filled dampers. This allows independent control of the damping characteristics of all four dampers.


Performance Traction Management (PTM) is a traction, stability and chassis mode control system accessed through the Track mode of the Driver Mode Control system. Driver Modes are selected by using the Mode button on the center console. Each of the five PTM modes provides progressively less stability control and more aggressive slip targets, allowing the driver more control over vehicle handling and performance.


Performance Data Recorder


The Performance Data Recorder is controlled through the Cadillac CUE touch screen. It records high-definition video from the frontview camera to the SD data card in the glove box. (Fig. 9) Recordings can be reviewed on the touch screen when the vehicle is parked or downloaded to a computer.


F09 ATSV pdr

Fig. 9


Refer to #PI1515 for additional information. To enroll in the available training courses on the ATS-V systems, go to (U.S) or, in Canada, go to GM GlobalConnect and select Centre of Learning.


To see the ATS-V and the Performance Data Recorder in action, ride along on the track in the video below.


F09A ATSV track


– Thanks to Sherman Dixon and Mark Gordon



Taking It to the Limit: Performance Traction Management

The performance of the 2016 ATS-V and CTS-V can be maximized for track events by using the Driver Mode Control and Performance Traction Management systems.


Driver Mode Control


Driver Mode Control changes the software calibrations of the suspension, steering and powertrain systems to adjust how the vehicle performs based on various driving preferences and road conditions. Owners should be made aware of these changes and how they affect vehicle performance.


There are four Driver Modes available: Tour, Sport, Snow/Ice, and Track. Track mode provides maximum vehicle handling performance and feedback. The Mode button on the center console enables drivers to select the different modes. (Fig. 10)


F10 Mode button

Fig. 10

Screen Shot 2015-09-28 at 11.11.50 AM

Performance Traction Management


Performance Traction Management (PTM) integrates the traction, stability and chassis mode control systems, accessed through the Track mode, and modifies the engine power for enhanced performance when cornering.


To select PTM, once in Track mode, press the Traction Control Off button twice. The current mode is displayed on the Driver Information Center. (Fig. 11) Press the MODE button on the center console to select one of the five available PTM modes:

• WET (Active Handling On)

• DRY (Active Handling On)

• SPORT 1 (Active Handling On)

• SPORT 2 (Active Handling Off)

• RACE (Active Handling Off)



Each mode progressively requires more driving skill by reducing the amount of traction control and stability control intervention and maximizing available engine power.


F11 CTSV track mode

Fig. 11


Launch Control


Launch Control is intended for use during closed course track events to help achieve high levels of vehicle acceleration in a straight line. It’s automatically activated when the vehicle is in Track Mode and any of the five PTM Modes are activated, the vehicle is not moving, and the steering wheel is pointing straight.


To use Launch Control, firmly depress the brake pedal or clutch pedal (if equipped), select 1st gear (manual transmission) or Drive, rapidly press the accelerator pedal to wide open throttle, and then release the brake pedal or clutch pedal while maintaining wide open throttle.


The Launch Control feature will initially limit engine speed as the driver rapidly applies the accelerator pedal to wide open throttle.


Track Events


If a vehicle spends a day at the track, there are also several maintenance procedures that should be followed.


Axle Fluid – Axles must have 500 miles (885 km) before being used in track driving. The axle fluid temperatures may be higher after driving in severe conditions. It’s recommended to change the fluid after the first track event, and then after every 24 hours of racing or competitive driving. The vehicle should not be driven as long or as fast the first time on the track.


Engine Oil – The supercharged 6.2L V8 engine (CTS-V) should use 0W-40 or 5W-40 oil that meets the dexos2 specification during track events.


Automatic Transmission Fluid (CTS-V) – Fill the transmission fluid to the track specific level prior to track use. If running a track session, check the transmission fluid level when the transmission fluid temperature is between 55-65°C (131–149°F).


Brake Fluid – For track events, it is recommended to use a high-performance brake fluid that has a dry boiling point greater than 279°C (534°F). After conversion to the high-performance brake fluid, follow the brake fluid service recommendations outlined by the fluid manufacturer. Do not use silicone or DOT-5 brake fluids.


Brake Disc Splash Shield (CTS-V) – Brake cooling can be improved if the front brake disc splash shield (Fig. 12) and front tire deflector are removed. Only remove the front brake disc splash shield and front tire deflector when driving in track events. Removing the shield will require that the suspension bushings visible to the brake disc be protected with insulated thermal wrapping.


F12 CTSV brake shield

Fig. 12


Brake Burnishing – To prepare the V-Series brake systems for track events, complete the appropriate high performance brake burnishing procedure outlined in the Owner Manual. During the burnishing procedure, the brake pads will smoke and produce an odor. The braking force and pedal travel may increase. After the procedure is complete, the brake pads may appear white at the rotor contact. Run this procedure in a safe manner and on dry pavement only.


Wheel Alignment – Wheel alignment specifications for track use are listed in the Owner Manual.


Tire Inflation – Tire pressure should be adjusted for various types of race courses. Refer to the Owner Manual for tire inflation pressure guidelines.


– Thanks to Sherman Dixon, Mark Gordon and Carrie Harvey



What Do You Think? Take the 2015 TechLink Reader Survey

At TechLink, our goal is to provide the latest GM technical news and repair information to help you quickly and accurately repair the vehicles that come into your service department every day.


We cover a wide range of topics, from the latest diagnostic and technical repair information to Techline programming, new model features, special tools and more.


We would like to hear from technicians and other service department professionals about the types of repair information to cover as well as get your thoughts on how we’re doing. Your input will help in determining the coverage of future editions. So which topics are of interest and value to you?


Click the following Survey link or click the Survey link on the right side of the home page to take a short survey about the information you want most in TechLink. The survey will be available until the end of October.


Take the Survey


Your input is very important to us. Thanks for taking the time to complete the survey. We’ll share the results when the survey is complete.


– Thanks to Lisa Scott

New Mini-B USB Test Cable for Trucks Available Soon

Designed for the infotainment systems available on 2014 Silverado 1500 and Sierra 1500 and 2015-2016 Silverado, Tahoe, Suburban, Sierra and Yukon models, a new Male Mini-B to Male Mini-B USB Cable (EL-50334-15) will be released soon that can be used to verify proper LVDS (Low Voltage Differential Signaling) cable operation between components.


The EL-50334-15 cable will be shipped to dealerships in January 2016.


Using the cable during diagnosis will help pinpoint issues with audio/video communication on the cable between any two of the three following components: ICS (Integrated Center Stack), HMI (Human Machine Interface) and Blu Ray player. (Fig. 13) This will help prevent unnecessary replacement of the ICS or HMI when the condition is the result of a faulty cable.


F13 EL-50334-15 cable

Fig. 13


The HMI is responsible for video, Bluetooth, USB, memory card reader, and speech recognition functions. The ICS assembly includes the infotainment display and controls.


The EL-50334-15 USB cable allows data transfer on pins 1,2,4,5, while 3 is shielded. An off-the-shelf USB cable cannot be used because pin 3 would be used to carry data and pin 4 would be the signal shield drain wire.


Other infotainment test cables, such as EL-50334-13 or EL-50334-14, cannot be used because a smaller connector end is needed on these applications.


– Thanks to Chuck Berecz and Troy Henige


Updated November 4, 2015


Unable to Select the Auto Memory Seat Recall Option

The Auto Memory Recall option may not be available in the Vehicle Settings menu on the infotainment system of some 2016 LaCrosse models equipped with Memory Seats (RPO A45) and built before August 6, 2016.


In order for the memory seats to recall the stored memory positions automatically when the ignition is turned on, Auto Memory Recall must be turned on in the Vehicle Settings menu.


The Auto Memory Recall option should be listed in the Comfort and Convenience menu. Go to Settings > Vehicle > Comfort and Convenience > Auto Memory Recall.


If the menu option does not appear in the menu (Fig. 14), update the K40 Seat Memory Control Module using SPS and the latest calibrations available on TIS2Web. Refer to Seat Memory Control Module Programming and Setup in the appropriate Service Information for more details.


F14 seat recall no menu

Fig. 14


After updating the Seat Memory Control Module, Auto Memory Recall will be listed in the Comfort and Convenience menu. (Fig. 15)


F15 seat recall menu

Fig. 15


– Thanks to Christopher Hightower

Sunroof Water or Air Leak

A water leak and/or wind noise from the sunroof or headliner area may be found on some 2015 Silverado, Tahoe, Suburban, Sierra, Yukon models and Escalade models equipped with a sunroof (RPO CF5) that were built prior to June 1, 2015.


The water leak may be difficult to reproduce and may require an extended water leak test. The leak may be coming from the headliner near the sunroof opening or cellular microphone grill and noticed at the left and/or right front floor/carpet if any water runs down the A pillars.


These conditions may be caused by the sunroof glass seal being out of specification, which allows water/air to leak between the sunroof glass and seal. (Fig. 16) Replace the sunroof seal to repair these leak conditions.


F16 sunroof seal

Fig. 16


– Thanks to Jim Will

Inoperative Left Front Audio Speaker

The left front audio speaker (Fig. 17) may be inoperative intermittently, cut in and out, or have poor audio quality on some 2015 Colorado and Canyon models equipped with the Enhanced Speaker System (RPO UQ3).


F17 speaker

Fig. 17


Inspect the left front tweeter wiring for:

• a possible pinched harness between the left side of the instrument panel carrier and mounting bracket

• a spread speaker connector terminal

• an incorrect speaker connector terminal (Fig. 18)

• shorted speaker wiring



F18 speaker connector

Fig. 18


Replacing the speaker will not correct the condition if there is damage to the terminals or wiring. Repair or replace any terminals or damaged wiring as needed.


– Thanks to Ryan Dorland

2016 ATS-V and CTS-V Front Spoiler Parts Ordering

The 2016 ATS-V and CTS-V models have a front spoiler, or splitter, delete option (RPO R6G) available when ordering a vehicle. These V-Series models have a base splitter (RPO C43) (Fig. 1) and an available carbon fiber splitter (RPO CFZ).


F01 CTSV splitter

Fig. 1


The vehicle pricing includes the base splitter, so dealerships that order any vehicles with the splitter delete option will be supplied with a base splitter that can be installed at the dealership. (Fig. 2)


F02 spoiler atsv



The Order Guide and other communications will cover this order concern. Overall, the number of V-Series models built and shipped without a splitter will be limited.

Screen Shot 2015-09-15 at 11.36.59 AM

Power Steering Fuse

Some 2010-2016 Equinox, Terrain; 2011-2015 Cruze, Volt; 2012-2015 Verano; 2013-2016 LaCrosse and Regal (equipped with RPO NJ1 – Non-variable Ratio Electric Power Steering), Malibu; 2014-2015 ELR; and 2014-2016 Impala (VIN 1) (equipped with RPO NJ1 – Non-variable Ratio Electric Power Steering) may have a loss of power steering assist or hard to steer condition and/or a Service Power Steering message displayed on the Driver Information Center. These power steering conditions may be caused by a blown/failed power steering fuse, which may result from improper jump starting.


If these conditions are found, check the power steering fuse and determine if the fuse is open by checking for continuity using a Digital Multimeter (EL–39200) or a continuity tester.


If the fuse element is broken, replace the fuse. When installing the new fuse, tighten the fasteners to 5 N×m (44 lb. in.).


If the continuity of the fuse is good, follow the appropriate Service Information to continue diagnosis.


– Thanks to Doug Daugherty

Radiator Leak and Engine Coolant Thermostat Housing Replacement

An engine coolant smell may be noticed while driving some 2014-2015 Silverado, Sierra; and 2015 Tahoe, Suburban, Yukon models and Escalade models. A coolant leak also may be found under the front of the vehicle.


Inspect the radiator for signs of leaks, especially where the tubes attach to the headers. (Fig. 3)


F03 radiator

Fig. 3


If a leak is found, it may be the result of excessive thermocycles within the cooling system caused by excessive cycling of the thermostat. The excessive thermocycles may cause the tubes to fatigue, crack and leak at the radiator headers. A new thermostat has been designed that eliminates the thermostat’s excessive cycling. Replace the radiator and the engine coolant thermostat housing, which includes the thermostat.


– Thanks to Jim Will

UPDATE: Steering Column Noise Conditions Repair

A grinding or popping noise or a binding feeling in the steering column when turning left or right may be experienced on some 2014 Silverado 1500, Sierra 1500; 2015 Silverado, Tahoe, Suburban, Sierra, Yukon models and Escalade models equipped with a tilt and telescoping steering column (RPOs N38, N37).


These conditions may be caused by the lower column bearing housing assembly being out of position (Fig. 4) or the upper intermediate steering shaft to lower column shaft bolt and nut may be contacting the inhibitor/shifter cable bracket. (Fig. 5)


TIP: Do not replace the steering column for these conditions.


F04 3924680

Fig. 4


F05 3924682

Fig. 5


To correct either condition, repair the steering column assembly by replacing the column lower bearing adapter assembly and retainer. Refer to Steering Shaft Lower Bearing Adapter Replacement in the appropriate Service Information for the complete repair procedure and torque specifications.


Here are some highlights of the procedure.


Remove the steering column as an assembly from the vehicle to remove the steering column lower bearing adapter assembly from the column. (Fig. 6)

F06 4248197

Fig. 6


Depress the retaining tabs using a flat bladed screwdriver to remove the lower bearing assembly from the column.


Install the new steering column lower bearing adapter assembly and a new steering column lower shaft retainer to the column by first measuring 154 mm (6.06 in) from the end of the steering column lower shaft and drawing a line around the shaft. (Fig. 7)


F07 4248198

Fig. 7


When installing the new steering column lower bearing adapter assembly to the steering column, make sure the bearing adapter is fully seated with the retaining tabs secured.


Install the lower steering column retainer to the measurement mark and verify a 3–5 mm (0.12-0.20 in) gap exists between the lower shaft retainer and lower bearing assembly. (Fig. 8)


F08 4248203

Fig. 8


– Thanks to Jim Will

Turbocharger Rattle on a Cold Start

The turbocharger on a 2016 ATS-V or 2014-2016 CTS Vsport may have a rattle sound on a cold start. Verify the sound is coming from the turbocharger.


A revised part is available to address the turbocharger rattle. The new part has a revised spring for the wastegate to limit movement when cold. The new part numbers for the right-hand (bank 1) (Fig. 9) and left-hand (bank 2) turbocharger assembly are now available.


F09 turbo

Fig. 9


Before installing the new turbocharger, clean any debris or excessive oil from the charge air cooler system. Any debris in the charge air cooler system will cause severe turbocharger and engine damage upon startup.


Also, when reconnecting the turbocharger oil feed pipe, install a new fitting. The fitting is not reusable.


– Thanks to David Antal

UPDATE: Loss of Power Steering Conditions

Some 2015 Colorado and Canyon models may have a loss of power steering assist, a hard to steer condition, or display a Service Power Steering message on the Driver Information Center. These conditions may be intermittent.


Check the Power Steering Control Module (PSCM) for DTCs.


If DTC C056D (Electronic Control Unit Hardware) is set, reprogram the PSCM with the latest calibrations available in TIS2WEB.


If DTC C0545 (Steering Wheel Torque Sensor) is set, replace the power steering gear assembly. (Fig. 10)


TIP: Replacement of the power steering gear assembly applies only to 2015 Colorado and Canyon models. If DTC C0545 is set on other models, contact TAC for more information.


F10 steering gear assembly

Fig. 10


– Thanks to Ken Cole

How to Remove Stuck Lifters

If a lifter has collapsed and is stuck in the lifter bore when completing Bulletin #15-06-01-002A (Engine Misfire) on some 2014-2015 Corvette, Silverado 1500, Sierra 1500; 2015 Tahoe, Suburban, Yukon models and Escalade models equipped with the 5.3L or 6.2L V8 (RPOs L83 L86 LT1 LT4 LV3), there are two approved processes for removing the stuck lifter.


The engine misfire condition may be the result of an Active Fuel Management (AFM) lifter that is mechanically collapsed and/or stuck. The lifter may be stuck because of internal locking pin damage due to oil aeration. Inspect the valve operation. If a valve is not moving, replace the valve lifter oil manifold and the affected bank of lifters.


If the lifter is stuck in the bore:


1. Use vice grips with a slide hammer. (Fig. 11)


F11 4250109 lifter 2

Fig. 11


2. Use vice grips with a small pry bar. (Fig. 12)


F12 4250108 lifter 1

Fig. 12


Be sure not to pry on the sealing surface of the block.


One of the approved processes should remove the lifter that is stuck in the bore. If not, the engine will need to be replaced.


With the lifter removed, inspect the bore for any damage. In most cases, the lifter bores will show no signs of damage.


– Thanks to Richard Renshaw

Rough Idle in Drive

Some 2015 Silverado 1500, Suburban, Tahoe, Sierra 1500, Yukon models, Escalade models; 2014 Silverado 1500 and Sierra 1500 models equipped with 4.3L, 5.3L, or 6.2L engines (RPOs L83, L86, LV1, LV3) may have a rough idle and/or vibration at idle in Drive. This condition may be most noticeable following extended driving, while idling at a stop in Drive. It will not be present in Park, Reverse, or Neutral.


There will not be any DTCs with this condition. Use the CH-51450-A (Pico Oscilloscope) for diagnosis. With the tool’s accelerometer positioned on forward end of the seat track, the condition will show in the lateral/cross-car direction as E1.5 (1.5 engine order) in the range of 2–7 mg.


This rough idle condition may be improved by performing a motor mount adjustment procedure. The mount adjustment procedure addresses the normal idle characteristics of the Gen-5 V6 and V8 engines transmitted through ground-out in the motor mounts due to frame bracket positioning tolerances.


TIP: Perform the following procedure on both left and right engine mounts at the same time so there is no binding/twisting in the mounts.


Begin by removing the front wheels and wheelhouse liners. Loosen the engine mount bolts at three frame attachment points for both the left and right mounts. (Fig. 13) Also loosen the transmission mount to keep from putting it into a bind. Lift the engine so both mounts are off the frame approximately 10-20mm.


F13 4236652

Fig. 13


Install 3mm-thick spacers between the bottom surface of the mount and frame bracket, on the inboard side of mount. Do not use tapered shims. Use a small amount of adhesive to hold the spacers in place on the frame.


Installing spacers between the mount and frame bracket at the lower inboard location, (Fig. 14, #1) alleviates the ground-out in the mount at the upper outboard area. (Fig. 14, #2)


F14 4236648

Fig. 14


Here is the washer location relative to the frame bracket. (Fig. 15)


F15 4224167

Fig. 15



Here is the washer location relative to the mount bottom surface. (Fig. 16)


F16 4224169

Fig. 16


Lower the engine so the spacers are trapped between the mount and the frame and tighten the bolts. Tighten the center/upper bolt first; then the front and rear bolt. Torque the mounts to 50 Nm (37 lb.-ft.).


For additional information, refer to #PIP5211.


– Thanks to Richard Renshaw

Service Know-How

10215.09D – Emerging Issues

September 10, 2015


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

Bulletin Review – August 2015

Screen Shot 2015-09-15 at 9.33.32 AM

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