SMU - SECTION 6E - ENGINE CONTROLS - CLEAR DTC'S. Chevrolet Chevy C Pickup

SUBJECT: SERVICE MANUAL UPDATE-SECTION 6E-ENGINE CONTROLS- CLEAR DTCS AFTER PCM OR VCM REPLACEMENT/PROGRAMMING OR EGR VALVE REPLACEMENT

MODELS: 1997 BUICK SKYLARK 1997 CHEVROLET CAVALIER, MALIBU 1997 OLDSMOBILE ACHIEVA, CUTLASS 1997 PONTIAC GRAND AM, SUNFIRE

1995-97 CHEVROLET AND GMC TRUCK S/T, M/L, C/K, G, P3 MODELS 1996-97 OLDSMOBILE BRAVADA WITH 2.2L, 2.4L, 4.3L, 5.0L, 5.7L, 7.4L ENGINE (VINS 4,T,J,M,R,W,X -RPOS LN2, LD9, L29, L30, L31, L35, LF6)

**PCM EQUIPPED VEHICLES** THIS BULLETIN IS BEING ISSUED TO REVISE THE 1997 GMP/97-N-2, 1997 GMP/97-J2 AND 1997 GMT/97-ST-2 SERVICE MANUALS. MAKE THE FOLLOWING REVISIONS TO THE EGR REPLACEMENT P0404, DTC P0405, DTC P1404 AND PCM EEPROM REPROGRAMMING SECTIONS OF THE SERVICE MANUAL DUE TO POSSIBLE SETTING OF EGR DTCS AFTER PERFORMING THESE PROCEDURES.

CLEAR DTCS FROM THE PCM ANYTIME EITHER THE PCM IS REPROGRAMMED OR THE EGR VALVE IS REPLACED, OR ANYTIME THE IGNITION SWITCH IS TURNED ON WITH THE EGR VALVE ELECTRICAL CONNECTOR DISCONNECTED. THIS IS DUE TO THE AUTO ZEROING FUNCTION OF THE PCM ON THE EGR PINTLE.

**VCM EQUIPPED TRUCKS** THIS BULLETIN UPDATES THE FOLLOWING SERVICE MANUALS:

* 1997 GMT/97-ST-2 * 1997 GMT/97-CK-2 * 1997 GMT/97-ML-2 * 1997 GMT/97-G6-2 * 1997 GMT/97-P3-2 * 1997 GMT/96-ST-2 * 1996 GMT/96-CK-2 * 1996 GMT/96-ML-2 * 1996 GMT/96-G6-2 * 1996 GMT/96-P3-2 * 1995 GMT/95-ST-2 * 1995 GMT/95-CK-2 * 1995 GMT/95-ML-2 * 1995 GMT/95-G6-2 * 1995 GMT/95-P3-2

ADD THE FOLLOWING REVISION TO THESE ENGINE CONTROLS SECTIONS: EGR VALVE, VCM REPLACEMENT/PROGRAMMING, EGR SYSTEM DIAGNOSIS, DTC P0401 AND DTC P1406.

CLEAR ANY DTCS FROM THE VCM ANYTIME AFTER DOING VCM REPLACEMENT/ PROGRAMMING, TURNING THE IGNITION ON WHILE THE EGR VALVE IS DISCONNECTED, OR REPLACING THE EGR VALVE.

PLEASE MAKE A NOTE OF THESE REVISIONS IN YOUR SERVICE MANUAL.

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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.