For 1990-2009 cars

# SMU - SECTION 6E - ENGINE CONTROLS - REVISED

REVISON: 01/24/97

#### THIS BULLETIN IS BEING REVISED TO INCLUDE THE TOYOTA CAVALIER.

#### SUBJECT: SERVICE MANUAL UPDATE-SECTION 6E-ENGINE CONTROLS- REVISED DTC P1601-SERIAL COMMUNICATION MALFUNCTION

#### MODELS: 1996-97 BUICK SKYLARK 1996-97 CHEVROLET CAVALIER 1996-97 OLDSMOBILE ACHIEVA 1996-97 PONTIAC GRAND AM, SUNFIRE 1996-97 TOYOTA CAVALIER WITH 2.2L AND 2.4L ENGINE (VINS 4, T - RPOS LN2, LD9)

THIS BULLETIN IS BEING ISSUED TO REVISE THE DTC P1601 TABLE FOR THE FOLLOWING SERVICE MANUALS:

* 1996 GMP/96-J-2 * 1996 GMP/96-N-2 * 1997 GMP/97-J-2 * 1997 GMP/97-N-2

IN STEP 2, THE TEST DESCRIPTION SHOULD READ: WHEN THE PCM CONTROLLED COOLANT LEVEL TELLTALE STAYS ILLUMINATED, SERIAL DATA IS LOST TO THE IPC.

IF THE ENGINE STARTS AND CONTINUES TO RUN, AN OPTIONAL TEST IS TO OBSERVE THE FOLLOWING TELLTALES AND GAUGES FOR PROPER OPERATION. IF ALL OF THESE TELLTALES ILLUMINATE OR THE GAUGES ARE NOT OPERATING PROPERLY, SERIAL DATA IS LOST TO THE IPC:

* OIL PRESSURE TELLTALE * VOLTAGE TELLTALE * TACHOMETER (IF EQUIPPED) * TEMPERATURE GAUGE (IF EQUIPPED)

IN STEP 2 OF THE ACTION COLUMN, THE STATEMENT SHOULD READ AS FOLLOWS:

1. TURN THE IGNITION SWITCH ON WITH THE ENGINE OFF. 2. OBSERVE THE IPC AND CHECK THE COOLANT LEVEL TELLTALE FOR ILLUMINATION. IS THE TELLTALE ON?

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.

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