INFO - NEW RPO CODE ZN4. GMC Truck Jimmy

REVISION: 11/03/98 DIVS INVL 1 5 7

THIS BULLETIN IS BEING REVISED TO ADD VIN BREAKPOINT INFORMATION. PLEASE DISCARD CORPORATE BULLETIN NUMBER 86-01-19 (SECTION 0 - GENERAL INFORMATION). ______________________________________________________________________

SUBJECT: INFORMATION - NEW RPO CODE ZN4

MODELS: 1998 CHEVROLET AND GMC S/T PICKUP MODELS 1998 ISUZU HOMBRE

BUILT BETWEEN THE FOLLOWING VIN BREAKPOINTS:

PLANT MAKE VIN BREAKPOINT ----- ---- --------------

LINDEN CHEVROLET WK241078 - WK271052 LINDEN GMC WK521278 - WK526682 SHREVEPORT CHEVROLET W8228338 - W8255243 SHREVEPORT GMC W8545611 - W8546052 SHREVEPORT ISUZU W8670594 - W8670669

BEGINNING SEPTEMBER 9, 1998, VEHICLE PRODUCTION FROM LINDEN AND SHREVEPORT ASSEMBLY CONTAINED THE RPO CODE ZN4. ZN4 EQUIPPED VEHICLE PRODUCTION HAS NOW ENDED. SEE THE VIN BREAKPOINT INFORMATION ABOVE FOR VEHICLES EQUIPPED WITH ZN4.

THE ZN4 OPTION APPLIES TO PICKUP MODELS ONLY. THE UTILITY MODELS; BRAVADA, BLAZER, AND JIMMY DO NOT HAVE RPO ZN4. THIS RPO REPRESENTS SIGNIFICANT ENGINEERING CHANGES TO MANY SYSTEMS AND COMPONENTS.

VEHICLES WITH ZN4 CAN BE IDENTIFIED BY THE FOLLOWING INFORMATION:

1. SERVICE PARTS IDENTIFICATION (SPID) LABEL, WITH RPO ZN4.

2. A SPECIAL UNDERHOOD (UH) LABEL, AFFIXED TO THE RADIATOR FAN SHROUD, THAT CONTAINS THE FOLLOWING INFORMATION:

**ATTENTION SERVICE TECHNICIANS: THIS 1998 VEHICLE IS EQUIPPED WITH RPO ZN4** REFER TO THE 1999 SERVICE MANUAL FOR PROPER SERVICE INFORMATION. FOR PARTS INFORMATION, REFER TO THE 1998 PARTS CATALOG FOR THE SPECIFIC ZN4 OPTION.

WHEN REPAIRING A ZN4 VEHICLE, USE THE APPROPRIATE SERVICE INFORMATION AS SPECIFIED BELOW.

1. USE THE 1999 S/T SERVICE MANUAL, PAPER COPY P/N GMT/99-ST, OR APPROPRIATE 1999 CD FOR ALL SERVICE INFORMATION.

2. USE THE 1999 LABOR TIME GUIDE FOR APPROPRIATE LABOR TIMES.

3. IN THE 1995-98 S/T PARTS CATALOG (54S), UNIQUE 1998 PICKUP TRUCK SERVICE PARTS WILL BE IDENTIFIED WITH RPO ZN4.

4. WHEN USING A TECH 2 TO PERFORM DIAGNOSTICS ON THE VEHICLE, SELECT THE ZN4 OPTION.

FIGURES: 00 ATTACHMENTS: 00

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.