CAMPAIGN: INCORRECTLY CALIBRATED SPEEDOMETER
SUBJECT: INCORRECTLY CALIBRATED SPEEDOMETER ADAPTER
MODELS: 1994-1995 TOPKICK/KODIAK AND B7 SCHOOL BUS MODELS
General Motors has determined that CERTAIN 1994-1995 B7 School Bus chassis and C7 TopKick/Kodiak model medium duty trucks equipped with certain Goodyear radial rear tire combinations were shipped with incorrectly calibrated speedometer adapters, which causes the speedometer and odometer to register approximately 8.5% high. This would reduce the emission warranty coverage to the owner.
To correct this condition, dealers will install a correctly calibrated speedometer adapter and reset the odometer to the correct mileage.
VEHICLES INVOLVED
Involved are CERTAIN 1994-1995 TopKick/Kodiak Medium Duty Trucks and B7 School Buses built within the following VIN breakpoints:
Year Make Model From Through
1994 GMC Truck B7T042 PJ511169 PJ526579 Chevrolet B7T042 RJ104102 PJ112577 1995 GMC Truck B7T042 SJ501264 SJ518239 Chevrolet B7T042 SJ103002 SJ109883 1995 GMC Truck C7H042 SJ504511 SJ504939 Chevrolet C7H042 SJ104058 SJ104500
The specific vehicles involved in this campaign have been identified by Vehicle Identification Number (VIN) Computer Listings. These listings are furnished to all involved dealers with the campaign bulletin. Dealers should confirm vehicle eligibility through VISS (Vehicle Information Service System) or SERVICENET prior to beginning campaign repairs.
DEALER CAMPAIGN RESPONSIBILITY
All unsold vehicles in dealers' possession and subject to this campaign MUST be held and inspected/repaired per the service procedure of this campaign bulletin BEFORE owners take possession of these vehicles.
Dealers are to service all vehicles subject to this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time forward.
Owners of vehicles recently sold from your vehicle inventory are to be contacted by the dealer and arrangements made to make the required correction according to instructions contained in this bulletin.
In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, please take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle.
If the name and address of the owner of an involved vehicle was unavailable to GMC Truck Division at the time of campaign initiation, the dealer must determine the owner's name and address from the dealership sales records. Please provide this information directly on the second copy of the listing next to the applicable VIN so that our records may be updated and the appropriate notification mailed to the owner. This second copy should then be submitted to the address listed below in the previously supplied yellow campaign envelopes.
GMC Truck Division General Motors Corporation 101 Union Street Plymouth, Michigan 48170
OWNER NOTIFICATION
Owners will be notified of this campaign on their vehicles by GMC Truck Division (see copy of owner letter included with this bulletin). A listing of owner names and addresses has been furnished to the involved dealers to enable dealers to follow up with owners involved in this campaign. This listing may contain owner names and addresses obtained from State Motor Vehicle Registration records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states. Accordingly, you are urged to limit the use of this listing to this campaign.
SERVICE PROCEDURE
NOTICE: Many solid state electrical components can be damaged by Electrostatic Discharge (ESD). Some will display a symbol but many will not. Be sure to follow the ESD Sensitive procedures listed in the 1995 TopKick/Kodiak, P6 Forward Control, and B7 Chassis Service Manual, Section 8C-Handling Electrostatic Discharge Sensitive Parts when performing the following procedure. Failure to do so could result in damage to the instrument cluster components.
TO REPIACE THE SPEED SENSOR MODULE
1. Disconnect the negative battery cable.
2. Locate the speed sensor module. The module case is white plastic.
TopKick/Kodiak Models - The module is located on the LH kick panel above the park brake handle.
B7 School Bus Models - Module location is on the RH side of the vehicle behind the Instrument Panel and below the maxi-fuses.
3. Unplug the I/P harness from the speed sensor module.
TopKick/Kodiak Models - For harness access, carefully remove the floor vent duct by removing one bolt and unsnapping four plastic tabs. Position the duct out of the way. Unplug the I/P harness from the speed sensor module. Squeeze the blue connector on the I/P harness to remove.
B7 School Bus Models - Unplug the I/P harness from the speed sensor module. Squeeze the blue connector on the Instrument Panel harness to remove.
4. Unsnap the module cover, remove the circuit board and discard. The module case has a hinged cover.
TopKick/Kodiak Models - The cover will open on the RH side of the case and swing right to left. This is a blind operation.
B7 School Bus Models - The cover will open on the LH side of the case and swing downward.
REFER TO ESD NOTICE AT BEGINNING OF SERVICE PROCEDURE.
5. Remove the new circuit board from the replacement assembly and discard the case. The new circuit board is serviced as a board and case assembly.
6. Install the new circuit board in the module on the vehicle. Reconnect the I/P harness to the speed sensor module connector plug.
7. TopKick/Kodiak Models - Reinstall the floor vent duct.
TO CORRECT THE VEHICLE'S MILEAGE -------------------------------- 1. Write down the vehicle mileage as read on the vehicle odometer.
2. Identify the vehicle's axle ratio.
TopKick/Kodiak Models - Check the RPO list located behind the passenger seat. It will state the axle RPO Option Code, Ratio Option/Single-Dual Speed Identification Number and the Axle Ratio.
B7 School Bus Models - Check the part number tag on the rear axle differential for the axle ratio. If unavailable, check the vehicle's RPO listing for the vehicle's Axle RPO Option Code and Ratio Option/Single-Dual Speed Identification Number and the Axle Ratio.
Refer to Figure 1 and locate the vehicle's Axle RPO Option, Ratio Option/Single-Dual Speed Identification Number, Axle Ratio and Correction Factor. Write down the correction factor.
3. Multiply the odometer mileage by the correction factor. The result is the vehicles true actual mileage. This is the mileage the vehicle odometer will read when it is returned to the customer.
REFER TO ESD NOTICE AT BEGINNING OF SERVICE PROCEDURE.
SAMPLE CALCULATION:
Odometer Mileage Correction Factor Actual Mileage
8,552.4 miles X 0.914 = 7,816.9
4. Remove the instrument cluster assembly.
TopKick/Kodiak Models - To remove the instrument cluster:
A. Remove the bezel (6 screws).
B. Disconnect the headlight switch connector.
C. Disconnect the dash/dimmer/dome light switch connector.
D. Loosen the air duct on the LH side of the cluster (2 screws).
E. Loosen the heater control assembly (5 screws) and reposition the assembly downward to obtain cluster fastener access.
F. Remove the cluster (four screws).
B7 School Bus Models - To remove the instrument cluster:
A. Disconnect the bezel (four fasteners and two plastic retainers) and position the bezel out of the way..
B. Unplug the I/P harness from the cluster assembly.
C. Remove four retainer screws on the cluster housing and remove the cluster assembly from the vehicle.
5. Remove the lens cover.
NOTICE: A flexible printed circuit located on the outside of the cluster housing connects the bezel to the base of the cluster housing. Care should be taken not to damage the printed circuit.
TopKick/Kodiak Models - Place the cluster assembly on a work bench and remove seven screws around the perimeter of the lens. Carefully lift off the lens and cluster bezel. Carefully flip or roll the cluster bezel back.
B7 School Bus Models - Place the cluster assembly on a work bench and remove five screws around the perimeter of the lens. Lift off the lens and cluster bezel. Carefully flip or roll the cluster bezel back.
6. Remove the screws from both the left and right gauge clusters. Lift the gauge clusters out of the cluster case being careful not to damage a ribbon cable located inside of the housing.
7. Unplug the ribbon cable connector from the printed circuit board located on the left side of the housing base.
8. Remove two (2) screws holding the odometer module in place and remove the odometer.
WARNING: IT IS AGAINST THE LAW AND GM POLICY TO SET A REPLACEMENT OR SERVICED ODOMETER TO ANY MILEAGE OTHER THAN ZERO OR THE ACTUAL VEHICLE MILEAGE (CALCULATED IN STEP 3)!
9. Reset the odometer to the correct mileage using the mileage calculated in Step 3 above and follow Steps 10 through 19 below.
10. Remove the metal retainer clip from the end of the odometer shaft.
11. Note the position and alignment of the projecting ears of the pinion carriers (on the bottom of the odometer wheels). The numerals exactly opposite these ears will appear in the odometer window. Use the tenths wheel numeral opposite these ears as a reference for setting the other wheels.
12. Carefully remove the plastic carrier retainer strip from the projecting ears on the bottom of the wheels. The plastic carrier retainer strip is thin and could crack or tear.
13. Hold the first figure wheel (tenths) between your right thumb and index finger. With the left hand index finger, rotate the first ear (between the ones and tenths wheel) completely around and back into its original position. This will increment the "ones" wheel. The carrier MUST be rotated one (1) full turn for each increase of the number.
14. Continue rotating this carrier until the wheel indicates the desired figure as it would appear in the odometer window. The pinion carrier must end up in its original position (as if the plastic pinion carrier retainer were installed) for the correct number to be displayed.
15. Shift the right hand thumb and index finger to hold and keep in alignment the first figure wheel, the first pinion carrier and the second figure wheel. With the left hand index finger, rotate the second pinion carrier until the third figure wheel indicates the desired figure. Continue working from right to left until each figure wheel is in its desired position.
16. Carefully reinstall the plastic carrier retainer on the odometer.
WARNING: IT IS AGAINST THE LAW AND GM POLICY TO SET A REPLACEMENT OR SERVICED ODOMETER TO ANY MILEAGE OTHER THAN ZERO OR THE ACTUAL VEHICLE MILEAGE (CALCULATED IN STEP 3)!
17. Place the odometer in the module frame. When placing the odometer back into the frame, the pinion carrier ears must line up to fit in the odometer frame groove provided for them.
18. Reinstall the odometer shaft metal retaining clip.
19. Reinstall the odometer module into the cluster case.
20. Replug the ribbon cable connector into the printed circuit board located on the left side of the housing base.
21. Reinstall the left and right gauge clusters.
22. Reinstall the cluster bezel and lens.
23. Reinstall the instrument cluster.
TopKick/Kodiak Models - To reinstall the instrument cluster:
A. Position the cluster assembly in place. Reinstall fasteners.
B. Reconnect the heater control assembly.
C. Reconnect the dash/dimmer/dome light switch connector.
D. Reconnect the headlight switch connector.
E. Reinstall the bezel.
B7 School Bus Models - To reinstall the instrument cluster:
A. Position the instrument cluster in place.
B. Replug the I/P harness into the cluster. Reinstall the cluster fasteners.
C. Reinstall the cluster housing.
D. Carefully reposition the bezel in place and reinstall.
24. Reconnect the negative battery cable.
25. Start the vehicle and check for proper operation of the headlights, directional indicator, I/P illumination and gauges.
26. Install "Campaign Identification Label".
PARTS INFORMATION
Contact Adistra Corporation at 1-800-627-5699 to acquire a replacement adapter. To procure the correct replacement adapter, the rear axle ratio must be supplied to Adistra. Parts will be shipped via "Next Day Delivery".
WARRANTY INFORMATION
Dealers should submit a warranty claim on each vehicle completed under this campaign.
Labor Operation *Time **Parts Cause Number Description Allowance Allowance Code -------------------------------------------------------------------------- V9700 B7 SCHOOL BUS - 0.7 $26.88 96 Replace Speed Sensor Module and Reset Odometer
V9701 TOPKICK/KODIAK - 1.0 $26.88 96 Replace Speed Sensor Module and Reset Odometer
For dealer to receive Administrative Time Allowance associated with this campaign, add 0.1 hour to the Labor Operation Time Allowance.
** The amount identified in the "Parts Allowance" column above represents 40% of dealer net for parts that are furnished in this campaign. This amount is to be placed in the Net Item Amount column of the claim and Type Code "M."
CAMPAIGN IDENTIFICATION LABEL
Each vehicle corrected in accordance with the instructions outlined in this product campaign bulletin will require a "Campaign Identification Label." Each label provides a space to include the campaign number and five (5) digit dealer code of the dealer performing the campaign service. This information must be inserted with a typewriter or ball point pen. This label is to be used in conjunction with the clear protective plastic cover provided with the Campaign Identification Labels.
Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in for periodic servicing by the owner.
Apply "Campaign Identification Label" only on a clean, dry surface.
Additional Campaign Identification Labels and covers are available in sheets of 49 by calling VISPAC, Incorporated at 1-800-269-5100 (Monday through Friday 8:00 AM to 4:30 PM EST).
ADMINISTRATIVE PROCEDURE
Procedures covering this campaign are outlined in Section V of your dealership's "GMC Truck Warranty Claims Processing Manual" #P9119 Rev. 2/94.
Dear GMC Truck Customer:
As a valued customer, your complete satisfaction with your GMC truck is our goal. In keeping with this goal, we want to let you know that we have discovered a problem that could affect your vehicle and we want to take care of it at no charge to you.
On a number of 1994-1995 B7 School Bus chassis and C7 TopKick/Kodiak model medium duty trucks equipped with certain Goodyear radial rear tire combinations were shipped with incorrectly calibrated speedometer adapters, which causes the speedometer and odometer to register approximately 8.5% high. This would reduce the emission warranty coverage to the owner.
To be absolutely sure that your vehicle is to specifications, dealers will install a correctly calibrated speedometer adapter and reset the odometer to the correct mileage
Instructions for performing this service have been sent to your GMC Truck dealer, and parts are available. Please contact your GMC dealer to arrange a service date as soon as possible. This procedure will take about 1 hour to complete, but you should ask how much additional time your dealer will need to schedule and process your vehicle.
The enclosed postage paid owner reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction to your vehicle in the shortest possible time. If you have sold or traded your vehicle, please furnish us the complete name and address of the person you sold or traded your vehicle to and return the card to us.
We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our product.
GMC TRUCK DIVISION General Motors Corporation
General Motors bulletins 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.
