P1621, P1336, P1626, P1631, P1632, MIL, NO START. GMC Truck Sonoma Pickup

REVISION: 07/06/98 DIVS INVL 1 5 7

THIS BULLETIN IS BEING REVISED TO CORRECT CALIBRATION INFORMATION. PLEASE DISCARD CORPORATE BULLETIN NUMBER 87-65-06 (SECTION 6E-- ENGINE FUEL AND EMISSION). ______________________________________________________________________

SUBJECT: P1621, P1336, P1626, P1631, P1632, MIL, NO START CONDITION, THEFT DETERRENT AND CRANKSHAFT POSITION SENSOR RELATED DIAGNOSTIC TROUBLE CODES (REPROGRAM THE PCM)

MODELS: 1998 CHEVROLET AND GMC S MODELS 1998 ISUZU HOMBRE WITH 2.2L ENGINE (VIN 4 - RPO LN2) AND 5 SPEED TRANSMISSION (RPO MW2)

VEHICLES INVOLVED:

INVOLVED ARE CERTAIN 1998 S-TRUCK MODELS EQUIPPED WITH THE 2.2L (RPO LN2) VIN ENGINE CODE 4, WITH RPO MW2 5- SPEED MANUAL TRANSMISSION ONLY. THESE VEHICLES FALL WITHIN THE FOLLOWING VIN BREAKPOINTS:

YEAR DIVISION MODEL PLANT PLANT CODE VIN THROUGH AND INCLUDING 1998 CHEVROLET S-10 LINDEN, NJ K WK146640 1998 GMC SONOMA LINDEN, NJ K WK506307 1998 CHEVROLET S10 SHREVEPORT, LA 8 W8141203 1998 GMC SONOMA SHREVEPORT, LA 8 W8510490 1998 ISUZU HOMBRE SHREVEPORT, LA 8 W8652526

CONDITION:

SOME CUSTOMERS MAY COMMENT ON AN MIL ILLUMINATION AND POSSIBLY A NO-START CONDITION WITH A P1621 AND/OR A P1336 DTC SET, AND VARIOUS DTC'S RELATED TO THE THEFT DETERRENT SYSTEM.

CAUSE:

A CONDITION MAY OCCUR WHERE THE PCM IS INDUCED TO RESET THE CRANKSHAFT POSITION SENSOR LEARN AND THE THEFT DETERRENT SYSTEM.

CORRECTION:

IF THERE ARE NO OBVIOUS MECHANICAL CONCERNS, REPROGRAM THE PCM WITH THE REVISED CALIBRATION THAT TAKES INTO ACCOUNT THE ABOVE CONDITIONS. THESE CALIBRATIONS ARE AVAILABLE ON CDROM #23 AND LATER VERSIONS. IN ADDITION TO THIS, THE CRANKSHAFT POSITION SYSTEM VARIATION LEARNING PROCEDURE MAY NEED TO BE PERFORMED, IF P1336 PERSISTS. PERFORM THE CRANKSHAFT POSITION SENSOR VARIATION LEARNING PROCEDURE USING INFORMATION FROM THE ENGINE CONTROLS SECTION OF THE APPROPRIATE SERVICE MANUAL.

SERVICE PROCEDURE:

1. INSTALL A SCAN TOOL AND VERIFY THAT ONE OF THE PREVIOUSLY NOTED DTC'S IS SET. 2. NOTE THE CALIBRATION ID CURRENTLY IN THE PCM. 3. REPROGRAM THE PCM WITH THE CALIBRATION NUMBER LISTED IN THE TABLE BELOW. 4. OPERATE THE VEHICLE AND CHECK FOR ANY ADDITIONAL DTC'S 5. IF THE VEHICLE EXHIBITS A DTC P1336 AFTER THE PCM HAS BEEN REPROGRAMMED, PERFORM THE CRANKSHAFT POSITION SYSTEM VARIATION LEARNING PROCEDURE AS NOTED IN THE ENGINE CONTROLS SECTION OF THE APPROPRIATE SERVICE MANUAL.

CALIBRATION NUMBERS:

USE THE CORRECT CALIBRATION FROM THE LIST BELOW.

CHEVROLET S10, GMC SONOMA, ISUZU HOMBRE:

ENGINE/TRANS NEW CAL BCC OLD CAL BCC USAGE ------------ ------- --- ------- --- -----

LN2 AND 5- 9356823 CLZR 9353913 CKRD LN2 : MW2 : GT4 SPEED MANUAL Z83/Z85 : NF2 TRANSMISSION FEDERAL TIER 1

LN2 AND 5- 9356833 CLZS 9354143 CKWF LN2 : MW2 : SPEED MANUAL GT4 TRANSMISSION Z83/Z85 : NB6 CALIF. TIER1

LN2 AND 5- 9356843 CLZT 9353923 CKRF LN2 : MW2 : SPEED MANUAL GT4 TRANSMISSION Z83/Z85 : NN8 UNL. EXPORT CHEV GMC

LN2 AND 5- 9356853 CLZU 9353933 CKRH LN2 : MW2 : SPEED MANUAL GT5 TRANSMISSION Z83/Z85 : NATIONWIDE NF2/NB6

LN2 AND 5- 9356863 CLZW 9353943 CKRJ LN2 : MW2 : SPEED MANUAL GT5 TRANSMISSION Z83/Z85 : NN8 UNL. EXPORT CHEV. GMC

LN2 AND 5- 9356873 CLZX 9353973 CKRM LN2 : MW2 : SPEED MANUAL GT4 TRANSMISSION ZQ8 : NF2/NB6 : SPORT SUSP. NATIONWIDE

LN2 AND 5- 9356883 CLZY 9353983 CKRN LN2 : MW2 : SPEED MANUAL GT5 TRANSMISSION ZQ8 : NF2/NB6 : SPORT SUSP. NATIONWIDE

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OPERATION LABOR OPERATION NUMBER DESCRIPTION TIME ---------------- ----------- ---------------

J6355 PROM REPROGRAM - USE PUBLISHED LABOR ON CAR OPERATION TIME

J6352 PROM REPROGRAM - USE PUBLISHED LABOR OFF CAR OPERATION TIME

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.