Compression Sense Ignition
Contents
1. Compression Sense Ignition service Information New and Improved Class 2 Corner Corvette Magnetic Selective Ride Control Te ee ee he mereg En ria 1 temi eeb kim Pe H Pee Hri ee Theft Deterrent Application Update j Airbag Zoning Tech Tips Carpet Separates from Sill Molding The first change you need to be aware of is the name Previously it was SI 2000 which reflected the year it was introduced To avoid having to change the name every year or so It will now be known simply as SI or Service Information The types of service materials available are essentially unchanged however A C Liquid Line Rubbing Wheel Speed Sensor Clips Cardan Joint Lubrication Mildew Odor or Wet Carpet Pontiac Vibe Service Tips Third Door Handle Bulletins eM Service and Parts Operations The new SI application has been streamlined You may notice the CD version no longer has a choice between Enhanced and Basic versions There is only one version and it s extremely user friendly continued on page 2 continued from page 1 The website home page is shown here You can make your choices from the thumbtabs at the top of the screen or from the bulleted list below Whether you are accessing the application from the CD or the web you will see the page shown here The top half of the page allows you to build the vehicle for which you want information The major change is that you can now do this on one p2. June 2002 Volume 4 No 6 Compression Sense Ignition An all new 2 2L engine RPO L61 VIN F is used in Pontiac Sunfire and Grand Am Oldsmobile Alero and Chevrolet Cavalier for 2002 This is an aluminum 4 cylinder engine with four valves per cylinder It uses a speed density fuel injection system and a waste Spark electronic ignition system Although waste spark ignition is familiar technology the L61 gives it a new twist L850 Compression Sense Ignition CSI CSI enables the Powertrain Control Module to determine proper engine phasing cam position without the use of a separate camshaft position sensor Components CSl s modular design is similar to the system used on the premium V6 and V 8 engines covered in the January 2000 TechLink Both systems house nearly all the major ignition system components in a single cassette although only the L61 engine uses compression sense Techline News The next time you use your Techline CDs or visit the Service and Parts Operations website http service gm com you will find a new appearance and some very useful new features A new graphic design is used in common between the CD and the web along with some new enhanced features The redesign is in response to user feedback The changes appear on CD version 12 issued in April 2002 and were added to the Internet website during the month of May The materials contained on the CDs and the material fou
3. CSI Components E Ignition EA Control Module A cylinder on its exhaust stroke has less in cylinder pressure than a cylinder on its compression stroke Because of these uneven pressures the spark plug of the cylinder on its exhaust stroke will break down first by a few microseconds and will spark first The order of the spark plug gap breakdown events for the paired cylinders is yet another characteristic that is reflected in the CSI signal The CSI Sensor The L850 utilizes a unique Compression sense Ignition sensor to detect the polarity events and the breakdown events in the secondary ignition circuits of each pair of cylinders This is accomplished by creating virtual capacitors between the secondary coils and the El module s electronics One side of these capacitor plates is connected to the ignition secondary outputs The other side is connected to a resistor network As current flows on the capacitor plates a voltage is created on this resistor The voltage pattern measured across this resistor is what makes up the information in the CSI signal Firing Order 1 4 3 2 4 1 2 3 Cylinder on Cylinder on Exhaust Compression waste spark fires second fires first 4 voltage 1 voltage 2 voltage 3 voltage 1 voltage 4 voltage 3 voltage 2 voltage The resistor network allows only the high frequency edge of the plug gap breakdown voltage to pass through for measurement We know that cy
4. GM TechLink on the Web http service gm com General Motors service tips are intended for use by professional technicians not a do it yourselfer They are written to inform those technicians of conditions that may occur on some vehicles or to provide information that could assist in the proper service of a vehicle Properly trained technicians have the equipment tools safety instructions and know how to do a job properly and safely If a condition is described do not assume that the bulletin applies to your vehicle or that your vehicle will have that condition See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information Inclusion in this publication is not necessarily an endorsement of the individual or the company Copyright 2002 General Motors Corporation All rights reserved Return to page 1 continued from page 1 Ignition Cassette Disassembled to Reveal Components Compression Sense At the moment an ignition coil fires a growing voltage potential is created across the gap of both plugs After about 10 microseconds the voltage reaches each plug s breakdown voltage level Breakdown is the point at which the air gap ionizes and conducts current causing the spark to occur The breakdown voltage level is determined in part by the pressure within the cylinder More voltage is required at a higher cylinder pressure
5. P N 12377985 88901242 in Canada or equivalent The slip yoke should also be Cardan Joint Cross Yoke Grease Fitting and Needle Type Applicator greased at the zerk fitting SI 2000 will be updated to include propshaft lubrication Service Thanks to Dan Oden Mildew Odor or Wet Carpet Owners of some S T pickups and utilities and Bravada may comment on mildew odor or wet carpet in the front passenger area There are three common causes Water Backing Up at Plenum Drain Too much sealer at the plenum drain area can act as a dam allowing water to back up in the plenum It seeps around the air box seal or around the lower right air box mounting screw Reduce the ridge of sealer to a height of 1 4 inch 6 3 mm or less with a utility knife Voids in Plenum Seam Sealer Use a mirror to examine the inside of the plenum for possible voids in the seam sealer Seal any voids following instructions in the service manual HVAC Recirculation Air Box Door Left Open With the HVAC controls set to MAX A C the recirc door opens upward In extreme conditions water can pool on top of this door and spill into the vehicle If the ignition is turned off with the controls set in MAX A C the door remains up Locate an intermittent entry point for the water Inform customers to turn the HVAC to regular A C or OFF before turning the ignition off Thanks to Monica Pruett Return to page 1 The 2003 Pontiac Vibe has se
6. 02 00 89 002A replaces 02 00 89 002 Information for Dealers on How to Submit a Field Product Report 2003 and Prior Passenger Cars and Trucks 02 00 89 003 Priority Access Service system P A S S 2003 Chevrolet and GMC MD Conventional Cab Models 02 00 89 004 Revisions to Courtesy Transportation Program 2002 and Prior Passenger Cars and Trucks 02 00 89 005 Dealer Disclosure Requirements 2003 and Prior Passenger Cars and Trucks 02 00 90 002 Lubrication of Propeller Shaft Double Cardan CV Type U Joint Centering Ball and Seat 1994 2002 Chevrolet and GMC S Extended Cab Pickup with V6 Engine C Extended Cab Pickup with Automatic Transmission RPO M30 HVAC 00 01 38 011A replaces 00 01 38 011 Poor Heat with Cold Outside Temperatures at Low Engine RPM Install Auxiliary Coolant Pump 1997 1999 Chevrolet Venture Oldsmobile Silhouette Pontiac Trans Sport 1999 Pontiac Montana 00 01 38 011B replaces 00 01 38 011A Poor Heat with Cold Outside Temperatures at Low Engine RPM Install Auxiliary Coolant Pump 1997 1999 Chevrolet Venture Oldsmobile Silhouette Pontiac Trans Sport 1999 Pontiac Montana STEERING 01 02 118 001A replaces 01 02 118 001 Parts Restriction Exchange Program for Quadrasteer Components 2002 Chevrolet and GMC Vehicles with Rear Wheel Steer Quadrasteer RPO NYS 02 02 32 005A replaces 02 02 32 005 Excessive Noise from Power Steering System While Turning or Under Light Braking Rep
7. Now airbag systems have grown to include on the 2003 Cadillac CTS for example a steering wheel airbag an IP airbag two side airbags two root rail airbags two seat belt pretensioners up to four sensors including a sensing and diagnostic module and numerous wiring harnesses spread widely throughout the vehicle Because the chances are greater than ever that you will encounter an airbag component when performing a service procedure vehicles are now divided into as many as a dozen different SIR Disabling and Enabling zones By following the proper procedure you can easily disable only those airbag components that are in the area where you re working And when you are finished you can just as easily enable the zone Depending on the complexity of the vehicle this can amount to a considerable time savings TIP The 2003 Cadillac CTS was the first vehicle to reach the market with the zone system all 2003 GM cars and trucks will be included when they arrive in the upcoming months Typical airbag zones TIP Because vehicle platforms are not all You will find separate instructions for each laid out similarly the number of zones will zone included on the vehicle you re servicing vary trom vehicle to vehicle but they all follow the same naming numbering scheme for sake of consistency TIP The service information for all vehicles follows the same organization so the paths are all identical To learn more abou
8. plate retaining clip with the wide portion of the retainer toward the center of the vehicle naapa 9 Mark the retainer s location on the carpet Then use an auto trim stapler to attach the retainer to the carpet Use three 12 mm 1 2 in galvanized staples TIP The bulletin recommends auto trim Staples If you substitute short trim screws or rivets file the excess off the back side to avoid creating noise Hook the retainer over the clip to retain the carpet in place Install the weatherstrip and sill plate to complete the repair Thanks to Wayne Zigler z Return to page 1 Wheel Speed Sensor Clips This affects Buick Century and Regal Oldsmobile Intrigue Pontiac Grand Prix and Montana and Chevrolet Monte Carlo Impala and Venture The wiring from the wheel speed sensor is a pigtail about 4 inches 100 mm long terminated with a connector The connector clips to a bracket on the steering knuckle During the 2001 model year the sensors were changed Connector clipped to bracket Pinch here with pliers to remove Early production used a stainless steel SS clip on the wiring connector which could be removed from the bracket simply by pulling Later production uses a plastic W clip which requires ordinary pliers for removal TIP Do not replace either style of clip with the other They are not interchangeable 12429204 old style with SS clip top left and 12429205 new style with W clip b
9. read by the PCM as a series of 4 data bits a 1 bit if CAM is high and a 0 bit if CAM is low The bits will be in the order of 1001 if cylinder 3 came up on High CAMOUT Signal Generation Compression ae 0 firing Coil Fires voltage k breaks over Voltage moves toward positive Voltage moves toward negative compression first or 0110 if cylinder 2 came up on compression first upon initiation of ignition during cranking The Tech 2 scan tool displays these bits as a parameter Saturn only using the following path Powertrain Data Display Engine Data Display Misfire Data Calculated Compression Output CCO The Tech 2 will actually display 8 bits but only the lower 4 bits are used The first 4 bits always remain as zeros Special Conditions The PCM needs to take into account engine operating conditions during which the in cylinder pressures for the pairs can be nearly equal During deceleration the pressure of the compressing cylinder can be as low as or lower than that of the cylinder on its waste stroke This condition would of course render the CSI signal information invalid For this reason the PCM will consider the CSI signal valid only during certain MAP ranges TIP This brief explanation shows how the Compression Sense Ignition system works as well as the inherent information the CSI signal provides A full length version of the story is available on the internet at www mat1424 com Th
10. age instead of three separate pages In some cases you may also want to click the Optional Vehicle Information button to further describe the vehicle you re working on If you choose to view Bulletins Campaigns and Preliminary Information the release date is now listed TIP Dashes are not required when searching directly for a bulletin or campaign The buttons in the bottom half of the page look and perform exactly as they always have with one exception There is a new button marked A This button allows you to search for bulletins by specitying a year range the vehicle platform and a keyword This is handy if you remember a bulletin but are not sure j heis et Pe Spree Baie a tanger ps Service Informaiion Home Te Wires i Servite Pubitauca Fre belet the Year Moke pod Mode of the Vebicle and click on Beat fae of the exact year it was issued If it falls within the range you specify you ll find it quickly And finally document printouts will now include the year make and model of the vehicle specified New Features Being Added Once the vehicle has been built you will have the opportunity to choose from the available service information For now the first choice is Service Manual and Bulletins As 2003 vehicles are added you will also be able to view the warranty book owner s manual and supplements Although much of this information is taken from owner literature it is reformatted fo
11. gnal will cause the CSTO chip inside the El module to send a CAMOUT high signal When the 1 4 coil fires as cylinder 4 is on compression the event will generate a positive then negative CSI signal This positive to negative CSI signal will cause the CSTO to send a CAMOUT low signal The 2 3 cylinder pair works the same way PCM Logic A variable reluctance crankshaft position CKP sensor is mounted in the engine block near the crankshaft The crankshaft has seven machined notches six of which are evenly spaced The 7th notch is positioned at 50 degrees ATDC of cylinder 1 4 and is used by the PCM as a sync pulse The engine always starts firing the 2 3 coll first during cranking Charging of the 2 3 coil always begins near the 2nd crank notch Charging of the 1 4 coil always begins near the 5th crank notch Once the ignition process has started with the 2 3 coil the PCM will look for the sequence of CAMOUT signals from the El module to determine engine phasing After 2 crankshaft revolutions all four cylinders will have fired and generated the 4 CAM ID bits continued on page 4 Firing Voltage Polarities Coil fires voltage rises in Positive direction Breaks over in a Negative direction Cylinder on compression Firing J voltage risesin Negative direction Breaks over in a Positive direction Return to page 1 continued from page 3 These sequences of high and low CAMOUT signals are
12. ility Symptoms MIL Illuminates Intermittently DTCs Set Engine Will Not Start Repair Wires 1997 2001 Buick Century Regal 2000 2002 Chevrolet Impala Monte Carlo 1999 2001 Pontiac Grand Prix 01 06 04 049A replaces 01 06 04 049 White Exhaust Smoke During Start Up Replace Engine Coolant Sensor ECT specified 2000 02 Chevrolet and GMC MD Trucks 02 06 01 010 Serpentine Belt Identification and Diagnosis 2001 02 Chevrolet and GMC C K HD Pickup Models with 6 6L Duramax Diesel Engine VIN 1 RPO LB7 02 06 01 012 Revised Harmonic Balancer 2002 Chevrolet and GMC S T Utility Oldsmobile Bravada 02 06 01 014 Revised Lower Intake Manifold Installation specified vehicles 1996 2002 with 3 1L or 3 4L Engine VINs J M E RPOs LG8 L82 LA1 02 06 01 015 Low Oil Pressure and New Oil Level Indicator 2001 02 Chevrolet and GMC C K G C6 7 MD B7 MD School Bus Models with 8 1L Engine VINs E G RPO L18 TRANSMISSION TRANSAXLE 01 07 30 023B replaces 01 07 30 023A Harsh 1 2 Upshift SES MIL or CEL Illuminated DTC P1870 Set Replace Valve Body 1996 Buick Roadmaster Cadillac Fleetwood 1996 2000 Chevrolet Camaro Corvette LD Trucks Pontiac Firebird GMC LD Trucks Oldsmobile Bravada 1999 2000 Cadillac Escalade with 4L60 E Automatic Transmission RPO M30 02 07 30 013 Incorrect Transmission Shifts Poor Performance of Engine Transmission Slipping SES Lamp Illuminated DTC P0756 P0757 Clean Transax
13. is site is sponsored by GM Marketing Area Team 1424 in Phoenix AZ In the left menu select Downloads Then select Compression Sense Ignition Part 1 You can then select the article plus the illustrations There are plans to offer Parts 2 and 3 on the website at a later date Thanks to Jim Garrido member of International Automotive Technicians Network and Kevin Schmidt Delphi New Vehicle Preparation Corvette Magnetic Selective Ride Control For 2003 Magnetic Selective Ride Control will be available on the Chevrolet Corvette Briefly when the vehicle is being driven various sensors pick up data which is processed by a control module Using pulse width modulation the control module varies an electromagnetic field in each damper which affects the thickening of the magneto rheological fluid within a millisecond A similar Cadillac system was described in the January 2002 TechLink When the ignition is turned off the dampers offer very little damping So the cars are shipped from the factory with the Suspension snugged down until the jounce bumper contacts a temporary plastic stuffer in each damper TIP The stuffers must be removed during new vehicle prep Failure to do so will result in customer dissatisfaction with the vehicle s ride quality To remove the stuffers lift the vehicle allowing the wheels to hang free This will extend the dampers At the front steer the wheel in the direction away fr
14. lace Power Brake Booster Inlet Hose 1999 2002 Chevrolet and GMC M L Van Models DRIVELINE AXLE 02 04 21 003 Revised DTC B2725 1999 2002 Chevrolet and GMC C K Pickup and Utility Models 1999 2000 Cadillac Escalade 2002 Cadillac Escalade Escalade EXT with NVG 236 246 Transfer Case RPO NP8 02 04 21 004 Service 4WD Indicator Illuminated DTC B2725 Set Replace Transfer Case Shift Control Switch 1999 2002 Chevrolet and GMC C K Pickup and Utility BRAKES 02 05 22 001 Revised Brake Specifications 1997 2002 Chevrolet Malibu Oldsmobile Cutlass and Alero Pontiac Grand Am 02 05 23 001A replaces 02 05 23 001 Uneven Brake Pad Wear Replace Caliper Mounting Plate and Install New Rear Brake Shield specified 1995 2001 Chevrolet and GMC MD Trucks with Four Piston Rear Disc Brakes RPO JNC 02 05 25 001 Yaw Rate Sensor Lateral Accelerometer Replacement 2002 Cadillac Escalade EXT with Stabilitrak RPO JL4 ENGINE PROPULSION SYSTEM 99 06 02 012D replaces 99 06 02 012C Rust in Cooling System Heater Inoperative Blows Cold Air Engine Overheats Flush Cooling System 1996 2000 Chevrolet and GMC S T Oldsmobile Bravada 1998 2000 GMC Envoy with 4 3 L V6 VINs W X RPOs L35 LF6 00 06 01 O006B replaces 00 06 01 006A Engine Tick Noise Purge Air from Valve Lifters 1999 2002 Chevrolet Tracker with 2 0L or 2 5L Engine VINs C 4 RPOs L34 LE8 00 06 05 049A replaces 00 06 05 049 Various Driveab
15. le Valve Body and Case Oil Passages of Debris specified 2001 02 Vehicles with 4T65E Transmission RPOs M15 MN3 MN7 M76 02 07 30 014 Servicing 4165 E Transaxle Spacer Plate and Gaskets specified vehicles 1997 2002 with 4165 E Transaxle RPOs MN3 MN7 M15 M76 02 07 30 015 Revised DTC P0713 2002 Buick Century Regal LeSabre Chevrolet Impala Monte Carlo Venture Oldsmobile Aurora Intrigue Silhouette Pontiac Bonneville Grand Prix Montana with 4165 E Automatic Transaxle 02 07 31 002 Intermittent Engine No Crank Repair Wiring and Install Wiring Protector specified Chevrolet and GMC MD Trucks BODY AND ACCESSORIES 01 08 57 007A replaces 01 08 57 007 General Waterleak Diagnosis Guide 1999 2002 Chevrolet Malibu Oldsmobile Alero Pontiac Grand Am 02 08 42 002 Headlamp Condensation 2002 Chevrolet Avalanche 02 08 42 004 PRNDL Display Reduced Visibility for Approximately One Minute 2002 and Prior Passenger Cars and Trucks with Auto Headlamp Control and Vacuum Fluorescent PRNDL Indicator Instrument Cluster 02 08 46 004 Cellular Error Messages Received When Trying to Connect to OnStar 2000 02 Passenger Cars and LD Trucks with Factory Installed OnStar 02 08 50 002 Driver Seat Movement During Acceleration and Braking Replace Adjuster Assembly 1997 2002 Chevrolet Corvette with Power Seats RPO AG1 or AG2 built prior to breakpoint 02 08 59 002 Rattle Type Noise Coming from Center of Dash Rem
16. linders fire in pairs and from the earlier study on polarity we know that the voltage of one plug moves toward positive while its pair moves toward negative And from the breakdown discussion we know that the plug in the cylinder on the exhaust stroke fires slightly before the one on the compression stroke These relationships can be seen in the accompanying chart The CSI signal will reflect the polarity and timing of each cylinder s spark plug breakdown voltage event Now that we have seen all the various pieces of information contained in the CSI signal as well as the method in which it is acquired let s pull it all together and see how it Is processed The CSTO The El module houses the CSI input Signal logic electronics called the Compression Sense Time Out CSTO chip The CSTO electronics are responsible for interpreting the CSI input signal and creating a 5V square wave output called a CAMOUT signal Here s how the CSTO chip logic works The first EST rise of either cylinder pair alerts the CSTO circuitry and the CSTO chip looks for the CSI input signal The CSTO chip Ignition Control Module recognizes unique characteristics of the CSI input signal then decides whether to send a CAMOUT high or CAMOUT low signal to the PCM As the chart above shows when the 1 4 coil fires as cylinder 1 is on compression the event will generate a negative then positive CSI signal This negative then positive CSI si
17. nd under the Service Information tab on the website are identical in every way The design Is the same and the way they perform is the same Now if you have to switch from one to the other you won t be confused by two different formats The ignition cassette is mounted directly over the spark plugs requiring only a connector spring and insulating boot to transfer the ignition energy to the spark plugs The cassette houses two ignition coils Each coil sends ignition energy to two paired cylinders at the same time one cylinder on its exhaust stroke and the other cylinder on its compression stroke Cylinders 1 and 4 are paired on one coil and cylinders 2 and 3 on the other Spark Polarities One spark plug in each pair always fires from the center electrode to the side electrode The other always Tires from the side electrode to the center electrode One cylinder s firing voltage rises in a negative direction relative to engine ground on the way to its final breakdown voltage It then quickly breaks over in a positive direction back toward ground until the spark line is established The other cylinder s firing voltage rises in a positive direction relative to engine ground then quickly breaks over in a negative direction back toward engine ground until the spark line is established The polarity characteristics of the spark events are one part of the information reflected in the CSI signal continued on page 3
18. om the side you re working on Reach up trom below behind the tire At the rear reach up trom below behind the tire At each wheel compress the rubber dust boot Pull the yellow tab to remove the stuffer then discard TIP After removing the stuffer be sure to pull the dust boot down to cover the upper end of the damper tube to avoid damage TIP The stuffers should not be reinserted for temporary transport such as on a flatbed hauler The stuffer is effective only if the Suspension can be snugged down enough for the jounce bumper to contact the stuffer This is generally not possible on a flatbed hauler Thanks to Brad Thacher and Dave Peacy Theft Deterrent Application Update Please add Camaro models for years 1998 1993 to the Theft Deterrent Application chart on page 4 of your April 2002 TechLink Passlock Po No system available for model Vehicle line is not in use System is undetermined Opel Immobilizer Chevrolet Camaro M Passkey II PK2 or VATS PASS Key Passkey III PK3 Passkey III PK3 Easykey Return to page 1 Airbag Zoning Early airbag systems consisted of a steering wheel airbag a control module several sensors and a wiring harness to tie them together When one of the airbag system components or another vehicle component in the general area needed service It was necessary to disarm the entire airbag system to prevent unwanted deployment
19. ottom right When you replace a wheel speed sensor wheel bearing assembly for bearing noise WSS code etc you must determine which type of sensor is on the vehicle and replace it with the same kind Check the parts book for details At the time the clips were changed the mounting orientation of the sensor was also changed Sensors with the old SS clip were mounted with the wire lead near the 6 00 o clock position New sensors with the W clip are mounted with the wire lead near the 2 00 or 10 00 o clock position depending on which side of the vehicle it s mounted This moves the lead away from the lower ball joint attachment as shown in the accompanying photo Thanks to Wayne Zigler Sensor wire lead location with the new W clip Cardan Joint Lubrication some 1994 2002 trucks such as the Chevrolet S 10 and GMC Sonoma extended cab with L35 V 6 use a propeller shaft that has double cardan type U joints A similar shaft is used as a service replacement on 1999 2002 2 wheel drive automatic extended cab Sierra and Silverado trucks Premature wear of the cardan joint ball and socket can result in noise and vibration at road speeds Premature wear may be caused by inadequate lubrication A grease passage In each cross yoke should be lubricated at normal chassis lubrication intervals You will need a needle type grease gun adapter such as Plews Stant 99 009 or 05 025 available locally Use Chassis Lubricant
20. ove Cowl Insulator Clip and Insulate Mounting Stud 2002 Chevrolet and GMC C K Pickup and Utility Cadillac Escalade with Gas Engine 02 08 61 001 Clicking Creaking Noise from Front of Vehicle Apply Penetrating Threadlocker 2000 02 Chevrolet Impala Monte Carlo 02 08 64 007 Third Door Hard to Open and or Handle Breakage Adjust Lock Rods 1996 2002 Chevrolet and GMC S T Extended Cab Pickup Models 02 08 64 008 Uncommanded Movement of Outside Rearview Mirrors Replace Mirror Actuator 2002 Chevrolet and GMC S T Utility Models Oldsmobile Bravada with Memory Mirrors RPO D25 02 08 66 004 Paint Rub Through on Liftgate Around Edge of License Plate Housing Pocket Install Insulating Seal Gasket 2002 Chevrolet and GMC S T Utility Oldsmobile Bravada 02 08 67 002 Headliner or Roof Rattle Replace Roof Drain Channel with New Design Channel 2002 Cadillac Escalade Chevrolet and GMC C K Utility Models Return to page 1
21. r the web This means you can select just the page s you need and they will load quickly The Labor Time Guide will be integrated into SI by the 4th quarter of 2002 Because the new version will be presented in service manual style there is no longer a need for a separate PDF version And it will include a keyword search capability Update Schedule SI Owners Manuals and Labor Time Guide will be updated on a regular basis as a package Currently SI web is updated once a week SI updates to the GM ACCESS server will occur every second Monday If there are updates to the LTG or the Owners Manual they will be included with SI updates Thanks to Bob Savo and Tom Tippen The Class 2 bus can be wired in one of two ways Star configuration and Loop configuration Both have their advantages and disadvantages The Star configuration connects each controller using a single wire trom each computer The wires are spliced together at a single location using a Splice Pack also called a Star Connector A splice pack Is a connector like component that uses a removable bus bar that connects all of the controllers together The advantage of the Star configuration lies in its relative ease of diagnosis The splice pack provides a convenient location in which to diagnose electrical problems associated with the Class 2 bus The disadvantage is that there is no built in redundancy to the system If an open occurs on one of these wi
22. res the controller will no longer be able to communicate on the bus The Loop configuration uses two wires connected to each controller One of the wires will connect to the next controller on the loop while the second wire connects to the previous one This creates a loop of controllers all holding hands as it were Each wire carries identical information so there is no specific input or output wire The advantage is that with two wires there Is redundancy built into the system If an open occurs on one wire the message can still be sent via the second one The disadvantage is in the relative difficulty of diagnosis Because there is no central location where the bus comes together you must isolate sections of the bus to do electrical checks Thanks to Mark Harris GM TechLink is a monthly magazine for all GM retail technicians and service consultants providing timely information to help increase knowledge about GM products and improve the performance of the service department This magazine is a companion to the GM Edge publication Publisher amp Editor Mark Stesney GM Service Operations lt Mark Stesney GM com Technical Editor Jim Horner lt Ja Jim Horner SandyCorp com 1 248 816 3641 Production Manager Marie Meredith Desktop Publishing Greg Szpaichler MediaWurks lt spake mediawurks com FAX number 1 248 649 5465 Write to gt lt TechLink PO Box 500 Troy MI 48007 0500
23. t airbag zones in SI 2000 follow this path Dealing with Codes Build the vehicle Disabling a zone will cause a Current Restraints diagnostic code to set Enabling the zone will SIR move the code to History Before returning Diagnostic Information and Procedures the vehicle to the customer you should clear SIR Disabling and Enabling Zones all History codes For specific procedures follow this path Build the vehicle Other Information Airbag zoning was discussed In a recent Restraints IDL broadcast For a replay of it look for SIR course number 10260 14D in the broadcast Repair Instructions schedule SIR Disabling and Enabling Zone 1 Thanks to Ken McLaughlin A C Liquid Line Rubbing On some 2002 Buick Century and Regal vehicles the A C liquid line may rub through at the transaxle side cover pan This may not occur until the vehicle has 20 000 miles 82 200 km on tt TIP To avoid this condition check this area during new vehicle predelivery inspection Thanks to Wayne Zigler Carpet Separates from Sill Plate Molding On some 1997 2001 Buick Centurys or Regals the carpet may pull out from under the rear door sill plate molding The repair procedure is explained in depth in bulletin 01 08 110 004 These are the highlights Part number 10414280 includes two plastic retainers one for each side With the sill exposed position a retainer over the sill
24. to Jeff Strausser and Russ Dobson Owners of some 1996 2002 extended cab S 10 and Sonoma pickups may comment on excessive effort or breaking of the third door handle This may be caused by improper placement of the attachment clips and or binding at the top latch Remove the door trim panel and release both lock rod clips Secure the upper rod Upper and lower rod clips clip on the right side of the door handle first Position the upper rod clip 10 5 12 0 mm approximately 11 12 threads showing from the end of the rod and lock it in place Position the lower lock rod clip left where it falls after the upper clip is in place usually 5 0 6 0 mm 5 6 threads showing from the end of the rod Make sure the upper striker is not bound against the latch If it is you must push the door inboard to release the latch To correct a bound latch adjust the striker by loosening two bolts at the top so the striker is centered in the latch Do not bend the striker Thanks to Monica Pruett Latch and striker Return to page 1 This review of service bulletins released through mid May lists the bulletin number superseded bulletin number if applicable Subject and models GENERAL INFORMATION 99 00 84 021C replaces 99 00 84 021B Expediting Parts 2003 and Prior Passenger Cars and Trucks 02 00 89 002 Information for Dealers on How to Submit a Field Product Report 2003 and Prior Passenger Cars and Trucks
25. veral unique service features you should be aware of nsmission Flui Use only ATF T IV transmission fluid not Dexron Ill Using the wrong fluid can cause harsh shifting Use only Dexron III transmission fluid not power steering fluid Failure to use the proper fluid can cause leaks and damage to the power steering system ANT Although the Vibe s coolant is tinted red it is conventional ethylene glycol not Dex Cool The cooling system is filled at the factory with a 50 50 mixture of water and ethylene glycol antifreeze This coolant solution provides freezing protection to 36 C 33 F Add Dex Cool coolant to the coolant reservoir when the coolant level is low Mixing green ethylene glycol to the factory red ethylene glycol results in brown coolant which may be a customer dissatistier When the system Is flushed at the recommended intervals fill the system with green colored ethylene glycol coolant If you use the J 41413 200 Evaporative Emission System Tester EEST December 2001 TechLink to locate a leak you will notice smoke coming from the drain hose This is a normal condition In order to check the system for leaks you must connect the EEST to the EVAP service port Bend the drain hose double while crimping it with locking pliers or equivalent before testing TIP Because the Vibe EVAP system Is similar to the Prizm this EVAP testing information applies to the Prizm as well Thanks
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