Campaign - 4WD Indicator Lamp Wiring
91chevy04
GMC NUMBER: 91-C-05
GROUP: 8B-CHASSIS ELECTRICAL
DATE: NOVEMBER, 1990
SUBJECT: 4WD INDICATOR LIGHT WIRING
MODELS: 1991 K 15-35 PICKUPS BUILT AT OSHAWA TRUCK ASSEMBLY CENTRE
General Motors has determined that on certain 1991 K 15-35 pickups built at the Oshawa Truck Assembly Centre the front axle indicator light may not work as intended. An electrical feedback condition may allow the light to remain on when the transfer case is shifted from 4wd to 2wd. If the vehicle continues to be operated in 2wd, this feedback condition will fail the front axle engagement switch causing the light to go out. When the vehicle is again placed into 4wd, the light will not go on and the RWAL system will remain enabled (normally disabled in 4wd). If the RWAL is activated while in 4wd, a diagnostic code 5 will be set in the RWAL module. This disables the RWAL function and causes the brake warning light on the instrument panel to illuminate and remain on.
To correct this condition a new wiring harness and front axle engagement switch will be installed.
VEHICLES INVOLVED
Involved are certain 1991 K 15-35 pickups built at the Oshawa Truck Assembly Centre. GMC VIN 's are listed below:
DEALER VIN
48-53507 2GTEK19K9M1514529
48-06450 2GTFK24K3M1514530
48-53531 2GTEK19C6M1514531
48-50323 2GTEK19K6M1514536
48-56149 2GDFK29K2M1514538
48-06507 2GTEK14K3M1514548
48-06333 2GTEK19H0M1514553
48-47122 1GTEK19KXM1514555
48-10291 2GTEK19K3M1514560
48-30201 2GTEK19K6M1514567
48-30606 2GTEK19K9M1514577
48-44622 2GTEK19K2M1514579
48-30017 2GTEK19K1M1514587
48-06519 2GTEK19K4M1514597
48-42048 2GTEK19K6M15l4617
OWNER NOTIFICATION
There will be no owner letter sent out with this campaign as it is anticipated the vehicles should still be in your new vehicle inventory and should be repaired prior to retail sale. If a unit has been retailed, in order to maintain customer satisfaction, contact the owner immediately and arrange to correct this condition on his/her vehicle.
SERVICE PROCEDURE
INSPECTION:
Raise the truck on a hoist and check the white 4-way connector at the front axle for wire colors (Figure 1). If the wire in cavity "A" is brown, the truck has the correct wiring harness. If correct proceed to Step 21 below. If the wire in cavity "A" is blue, the harness and the front axle switch must be changed. Proceed to "Repair Section" below. Lower the truck.
Figure 1:
REPAIR:
1. Prepare the truck; disconnect the negative battery cable.
2. Remove the clamp on the right frame rail that holds the battery cable and the wiring conduit from the front axle switch (Figure 1).
3. For R05 (dual rear wheels) only, disconnect the relay connector from inside the convenience center at the right side of the truck. The relay connector will be the one toward the driver's side (Figure 1).
Figure 2:
4. Disconnect the engine wiring harness connector behind the engine. This is a purple wire behind the engine, located approximately at the edge of the transmission bell housing (Figure 2. View A). This connector is more accessible from under the hood, but is viewed easier from under the truck. Thus you may want to raise the truck before disconnecting this connector.
WARRANTY INFORMATION Dealers should submit a warranty claim on each vehicle completed under this campaign.
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 may be inserted with a typewriter or ballpoint pen.
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.
ADMINISTRATIVE PROCEDURE
Procedures covering this campaign are outlined in Section V of your dealership's "GM Truck Claims Processing Manual" # P8919.