Archive for January 2012
10212.01D – Emerging Issues
January 12, 2012
To view Emerging Issues seminars:
Log in to www.gmtraining.com, 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.
On 2009-2012 Express and Savana Cutaway Vans, there may be some confusion regarding the proper operation of the stop and/or turn signals. This could lead to difficultly diagnosing a stop and/or turn signal condition. There are two different ways the Body Control Module (BCM) can be calibrated for stop and turn signal operation:
1. Without RPO V4D – The stop and turn signals are one lamp (same bulb). Traditionally, there will be one red stop/turn signal lamp per side. There are circuits for the left stop/turn signal and the right stop/turn signal.
2. With RPO V4D – The stop and turn signals are separate lamps (two different bulbs). Traditionally, there will be one red stop lamp and one amber turn signal lamp per side. There are circuits for the left turn signal only, right turn signal only, and the stop lamps only.
RPO V4D is included with the Ambulance Package (RPO YF2), School Bus Package (RPO B3D) or Shuttle Bus Package (RPO ANC).
If the vehicle is upfitted and the body does not support the way the BCM is calibrated for the stop/turn signal setup, contact the Techline Customer Support Center for a new BCM calibration to either remove or add the RPO V4D option.
- Thanks to Jim Will
On the 2012 Sonic, the HVAC system can produce additional background noise that may affect the performance of the in-vehicle microphone for speech recognition, OnStar, and Bluetooth phone calls. The HVAC system does not automatically decrease in intensity when an OnStar or Bluetooth call is made. This will create a louder cabin environment and may affect the ability of the in-vehicle microphone to receive a clear signal. In addition, when the center panel vents (in the center stack above the radio) are directed upwards, the airflow can directly interfere with the microphone.
If customers are experiencing issues with speech recognition or with their voice quality on phone calls, instruct them to redirect the center panel vents downward or change the airflow setting away from Vent or Bi-Level to reduce the background noise. (Fig. 15)
- Thanks to Bryan Brunner
During the installation of the GM Accessory illuminated sill plates on the 2011-2012 Cruze, the hole drilled in the trim panel needs to be elongated to relieve stress on the wiring harness.
The current hole location puts too much stress on the electrical connector joint on the sill plate. Elongate the hole on the harness side of the sill plate slightly to relieve the stress on the harness.
- Thanks to Chris Hightower
While performing mechanical engine repairs on some 2009-2011 Aveo; 2011-2012 Cruze; 2012 Sonic; 2009-2010 Wave/G3; and 2008-2009 Astra models equipped with the 1.6L 4-cylinder engine (RPO LXV) or 1.8L 4-cylinder engine (RPOs LUW, 2H0), a melted plastic piece may be observed in the engine block deck. If an engine is severely overheated, the high temperature plastic oil feed restrictor orifice in the block deck (Fig. 13) may become damaged, restricting oil flow through the block, orifice and cylinder head passages. (Fig. 14) The orifice is toward the exhaust side of the block, between cylinders 2 and 3. It may be difficult to locate this item in the parts catalog.
If it becomes necessary to replace the oil feed restrictor orifice, search the following terms in the parts catalog:
• Aveo and G3/Wave: Search the term plug
• Astra: Search the term restrictor
• Cruze and Sonic: Search the term valve
These searches will pull up the necessary part and the latest part number.
- Thanks to John Kopec
If the low side suction line between the condenser and compressor or the condenser on a 2010-2011 Aveo requires replacement, keep in mind that the first design low side A/C suction line and condenser have been discontinued. When replacing the parts, the suction line will not mate with the condenser if different design parts are used.
If the vehicle has the first design parts (Fig. 11) on it, the second design parts (Fig. 12) are needed. If the vehicle has the first design condenser or AC line, order the following parts:
• A/C condenser, P/N 95227758
• A/C low side suction line, P/N 96802198
- Thanks to Ernest Haller
On a 2011-2012 Regal with a tire inflator kit (RPO WTR), a rattle or buzz may be noticed at the rear of vehicle.
The source of the noise may be the tire inflator pump hold-down nut, which may be loose or cross-threaded. (Fig. 10)
Inspect the hold-down nut for the tire inflator pump in the trunk. If the nut is loose, make sure it was not cross-threaded when installed. Repair the threads using a tap and die as needed or replace.
- Thanks to Chris Crumb
It’s a well-known principle that following Service Information (SI) procedures is a good way to avoid unintended problems. That is certainly true when using Room Temperature Vulcanizing (RTV) Sealer.
RTV provides an excellent seal when used according to instructions, but problems can arise if too much is used.
SI says to use a bead size as specified in the procedure. It’s easy to see that too little RTV may not provide the intended proper seal. But if too much RTV is used, the excess may be squeezed from between the sealing surfaces, where it cures. From there, pieces of it may loosen and make their way into unintended places. For instance, too much RTV used to seal a lower crankcase could end up in the engine oil supply, causing restriction or complete blockage of a critical oil passage.
Excess RTV that has oozed into a blind threaded hole may cause damage when the bolt is tightened, or it may interfere with the proper torque of the bolt threads.
Also be careful when removing old RTV before resealing mating parts. Be sure all the loose pieces of old RTV have been completely removed so they don’t fall into unintended places.
- Thanks to Dave Peacy
On vehicles with BTM (Battery Thermal Module), there are several conditions that may cause a Remote Keyless Entry transmitter (key fob) not to program.
A failure of the immobilizer coil to communicate with the key fob will prevent the programming process from being successful.
The immobilizer can be communicating with the BCM, but communication may not be established with the key fob. There are at least two possible causes for this condition that are NOT related to a faulty key fob:
• A key fob that is not positioned properly within the fob programming pocket.
• An immobilizer coil that is not mounted in the correct position. Check to see if the immobilizer coil is mounted/snapped into the correct position.
For more information, refer to #PI0052B in the Service Information, which contains diagnostic tips for programming. These include keeping at least one door open during programming, not opening the trunk, avoiding low frequency interference, and making sure that additional keys on the key ring are not preventing the fob from properly seating in the pocket, among others.
Refer to the March 2011 TechLink article on Remote Transmitter Pocket Locations for descriptions and photographs of the locations of the remote transmitter pocket on several vehicles.
- Thanks to Vivian Williams
On a 2003-2007 Saturn ION, the brake warning light may be illuminated and DTC C0129 (Low Brake Fluid Circuit High) may be set. This condition generally occurs after the fluid switch or brake fluid reservoir was replaced.
Measure the resistance of the fluid level switch. The value for the closed position (low fluid) is 2.7 ohms and the open position (normal state) is 2K ohms. If the switch is out of range, replace the switch.
If the switch is in the normal range, follow published diagnostics in the appropriate Service Information.
- Thanks to Ernest Haller
On 2012 and prior GM passenger cars and light-duty trucks equipped with a USB port, an MP3 player or iPod® may be inoperative when the vehicle is first started, or the radio may switch to the USB source after a few minutes of driving.
If the vehicle is turned off with the USB device (iPod or equivalent audio device) still connected, the device will continue to play until its battery goes dead.
TIP: The device will not charge if left plugged in when the vehicle is turned off.
When the vehicle is started, the device will start charging. The device may need to charge for a few minutes before it will have enough power to turn on. Once it turns on, the radio recognizes that a device is plugged in and automatically switches to the USB source.
Explain to the customer that this is normal operation.
- Thanks to Ryan Dorland
On some 2011-2012 Regals, a rubbing or squeaking noise may be heard coming from the base of the steering column when turning the steering wheel on a cold morning.
The intermediate shaft dust seal may be out of position and not seated properly in the sheet metal on the engine compartment side. This may cause the rearward lip of the seal to fold into the opening where the intermediate shaft exits the passenger compartment.
The best way to check for this condition is to lift the inner seal (in the passenger compartment) to see if the outer seal is contacting the intermediate shaft. (Fig. 8) The noise that the seal makes when contacting the shaft is louder when it is cold.
The seal can be repaired by tucking it back into place (Fig. 9), or if necessary, drop the cradle and reseat the seal. Correctly positioning the intermediate shaft dust seal will eliminate the noise.
- Thanks to Christopher Crumb
On some 2006-2012 LaCrosse (Allure), Lucerne; 2011-2012 Regal; 2010-2012 Camaro; 2005-2012 Corvette; 2006-2012 Impala; 2006-2007 Monte Carlo; 2004-2012 Malibu; 2012 Sonic; 2005-2012 CTS, SRX; 2006-2011 DTS; 2005-2011 STS; and 2005-2009 XLR models, a difference in audio levels may be noticed when switching between favorites/presets and/or audio bands. It may be noticed that the condition is happening when going between AM/FM, CD, and/or XM bands.
Verify that the equalizer settings are all set to the same levels for each band when comparing audio differences. When storing the stations, it may also store the EQ settings. The increased or decreased bass and treble settings will enhance the level of noticed change.
In addition, try multiple CDs. This may be normal due to variations in the CD/MP3 burning process with commercially or consumer produced discs.
If the condition changes with either the equalizer settings or multiple CDs, this is normal and no parts should be replaced.
- Thanks to Ernest Haller
Dexron VI fluid was introduced in the power steering systems on the Acadia, Enclave and Traverse in production during the 2012 MY.
There may be some questions about the use of Dexron VI fluid in the power steering system when performing a repair on these vehicles from a past model year: 2007-2012 Acadia, 2008-2012 Enclave, 2009-2012 Traverse, and 2007-2010 OUTLOOK.
Refer to #PI0620 for information on using Dexron VI in the power steering system. The information includes:
• The procedure for converting the system to Dexron VI
• How to procure an identification tag for the power steering reservoir to identify that the system has been converted
• Conditions under which this conversion should be performed
To prevent a pinion seal squeak in the future, it is recommended to convert to Dexron VI only when a steering gear is replaced. It is not recommended to convert to Dexron VI for any other service to the power steering system because the pinion seal has already been exposed to the old fluid, which is the cause of the squeak condition. Converting to Dexron VI without changing the pinion seal would not prevent a pinion seal squeak in the future.
Furthermore, if a squeak should develop from the steering gear pinion seal, it is imperative to convert the system to Dexron VI before replacing the pinion housing and inlet hose as outlined in #PI0029F. The new housing recommended as part of this service procedure contains a fresh seal that must not be exposed to, or contaminated by, the old fluid or it may develop a squeak in the future. The new inlet hose also has a larger diameter orifice to allow for less system back pressure.
- Thanks to Gary McAdam
The 2012 Chevrolet Camaro ZL1′s supercharged 6.2L V8 engine is SAE-rated at 580 horsepower and 556 lb.-ft. of torque, making it the most powerful production Camaro ever.
The 2012 Camaro ZL1 surpasses the advertised power of the legendary 1969 Camaro ZL1 427 cubic-inch big block by more than 150 horsepower — while meeting modern emissions requirements.
The ZL1′s outstanding power is complemented by advanced powertrain and chassis technologies, including exclusive Performance Traction Management and a third-generation Magnetic Ride Control system. Track-capable standard equipment includes a high-performance fuel system as well as engine, transmission and differential coolers.
The ZL1 is equipped with a 6.2-liter supercharged V8 engine (RPO LSA) (Fig. 2) that is rated at 580 horsepower and 556 lb.-ft of torque and is available with the standard six-speed manual (RPO MG9) or optional Hydra-Matic® 6L90 automatic (RPO MYD) transmission. This engine features an intercooled supercharger system and premium heat-resistant aluminum-alloy cylinder heads. It also features hypereutectic pistons with forged connecting rods, piston cooling oil squirters, standard oil cooler and deep sump oil pan.
Its 1.9L Roots-style blower uses an efficient four-lobe rotor set and compact higher-efficiency intercooler to deliver boosted air into the high-flow cylinder heads.
An engine-oil cooler is identical to the system on the Corvette ZR1. The integral liquid-to-liquid system is so effective that vehicles with either the manual or automatic transmission are deemed to be fully track-capable with the standard factory-installed cooling package.
TIP: ZL1 performance parts have a break-in period. For the first 1,500 miles (2,414 km), avoid full-throttle starts and abrupt stops, do not exceed 4,000 engine rpm, avoid driving at any one constant speed, and do not drive above 80 mph (129 km/h). Following these break-in period guidelines will result in better performance in the long run.
The standard transmission for the ZL1 is the latest TREMEC (TR6060) 6-speed manual, which offers 30 percent more torque capacity than in the Camaro SS. The higher torque capacity results from a strengthened output shaft, high-strength rear housing, and additional roller bearing.
Similarly, the Hydra-Matic 6L90 6-speed automatic has been strengthened to handle the torque and horsepower produced by the 6.2L supercharged small block. The 6L90 features a strengthened input gearset with two additional pinion gears, additional clutch plate, and a strengthened output shaft and gearset.
The 6L90 transmission features three distinct drive modes calibrated for optimal fuel economy (Drive), more aggressive driving (Sport) and true manual control (Manual) with no automatic upshifts.
The dual-mode exhaust of the ZL1 provides refined tuning (optimal noise and vibration characteristics) at low engine speeds and a low-restriction exhaust (enabling peak horsepower performance) at high engine speeds in one exhaust system. It utilizes a vacuum system similar to Corvette, coupled with twin valves located at the exhaust tailpipes.
Although both Corvette and Camaro use vacuum actuated exhaust valves, there are differences. In the Camaro, the control software resides in the chassis control module that contains other software, to reduce the number of modules in the vehicle.
The Corvette is calibrated to open the exhaust valves only during aggressive driving, when engine rpm and throttle position exceed certain values. The Camaro is also calibrated to be open during aggressive driving. In addition, it is calibrated to open the valves at engine idle and up to 1,000 rpm.
High-Performance Fuel System
The fuel pump and tank have been modified to maximize the amount of fuel available during high performance maneuvers. The system features additional fuel pickups on the primary side, and the secondary fuel pickup is moved outboard for continuous fuel access during high-G cornering under low fuel conditions.
TIP: Premium fuel is required.
Magnetic Ride Control™
The ZL1 suspension (Fig. 3) features the third-generation of Magnetic Ride Control (MRC). MRC employs valveless damping and magneto-rheological (MR) fluid technology. For the third-generation, MRC uses new twin-wire/dual-coil dampers at all four corners. The smaller dual-coil system — with one coil at either end of the damper — replaces the larger single-core design of the previous generation. The new dual-coil design enables faster response, with damping levels now adjusted up to 1,000 times per second – about one adjustment per inch of vehicle travel at 60 mph – making the system exceptionally responsive to changing driving and road conditions.
There are three settings for MRC in the ZL1: Tour, Sport, and Track.
For a look at the tuning of the MRC system, click here.
Electrically Assisted Steering
Electrically Assisted Steering (EAS) is an innovative power-assist system connection between the ZL1 steering system and the engine. The assist power is applied directly to the rack with a belt drive and a ball nut mechanism. This design allows for lower inertia, lower friction and more direct steering feel, as well as superior response.
Performance Track Management
Exclusive to GM and first introduced on the Corvette ZR1, Performance Track Management (PTM) is a feature that tailors the performance of the ZL1 to match the driver’s skills and driving conditions. This advanced system integrates Magnetic Ride Control, launch control, Traction Control and stability control. Five PTM performance levels or modes are available through the Driver Information Center.
To watch the development of the ZL1 launch control system, click here.
The ZL1 is equipped with a large, extremely robust, Brembo brake system (Fig. 4) with 6-piston front and 4-piston rear calipers and ventilated two-piece front and one-piece rear rotors.
TIP: Due to the floating design of the brake rotor, the front brake rotor cannot be refinished. If the front brake rotor is found to be at or below the minimum specification, it must be replaced.
Click here for details on ZL1 endurance testing of the performance components.
Wheels and Tires
The ZL1 offers two 20-inch wheel options. Both designs are 20×10-inch front and 20×11-inch rear sizes.
Both wheels have larger tires mounted to them that contain a special rim protector. The rim protector, built into each tire, puts rubber over the aluminum of the outer rim for protection when parking. (Fig. 5)
The Goodyear Eagle® F1 Supercar® Generation 2 (G:2) tires have been developed and optimized specifically for the ZL1 to yield outstanding handling while maintaining requisite street-tire performance for wet handling, tread wear, noise, mass and rolling resistance.
It is not recommended to use the high-performance summer tires when temperatures drop to approximately 40 degrees F (5 degrees C) or below. It is recommended these tires be stored indoors at temperatures above 20 degrees F (-7 degrees C) when not in use.
The ZL1 tires should not be rotated. They are corner specific by design. These tires are unique in their wear patterns. The outside shoulder may appear worn as compared to other tires.
Underbody Belly Pan
The ZL1 underbody incorporates a belly pan that helps reduce front lift. The shape was enhanced to draw air upward into the underbody area. This highly energized air provides extra cooling for underbody components affected by the additional exhaust thermal energy of the high-powered LSA engine.
The underbody belly pan will need to be removed before performing service work, including oil and filter changes.
The front view of the ZL1 is highlighted by an aluminum hood with functional carbon fiber “mohawk” extractors. Carbon fiber provides strength, durability and low mass. The extractor is available in either black paint or exposed weave.
TIP: The black painted carbon fiber “mohawk” requires unique care when cleaning. Do NOT apply wax or polish to the flat black portion of the hood or extractors. Applying wax or polish to this portion of the hood will result in a cloudy haze to the finish. The optional exposed carbon fiber weave version can be waxed like the rest of the surface of the car.
The front fascia has a large lower splitter to reduce front lift and force air through the larger lower grille. (Fig. 6) The larger openings, splitter and hood extractor all combine for a significant increase in cooling capacity for the powertrain.
The ground clearance of ZL1 is similar to a Corvette ZR1. This requires care when lifting, driving on inclines and approaching curbs.
Learn more about the aerodynamics of the ZL1 here.
Pre-Delivery Inspection (PDI)
During PDI, remove the spring spacers (Fig. 7) from the front suspension and place them in the glove box for the customer. If the car is to be on a trailer for any reason, the spacers need to be placed back in the front springs to obtain ground clearance.
TIP: Initially, the Camaro front spring spacers will be black. In April, they will be made yellow for easier visibility.
Before delivery, hand wash the car. Due to the larger width wheels, most car wash tracks will not accommodate the wider wheels
Due to the low ground clearance, it’s necessary to be extra careful when driving the vehicle onto a ramp (such as an alignment rack) or when using a hydraulic lift.
Lifts are not all alike. Heights, adjustability, dimensions, and floor contour can vary, so specific instructions are not possible. Compare the vehicle’s dimensions with your lift or alignment rack to determine what accommodations are needed to lift the vehicle without damage.
To experience how everything on the ZL1 comes together, click here.
- Thanks to Brad Thacher and Jack Pantaleo