SMU - SECTION 6E2 - C7 - DRIVEABILITY & EMISSIONS. Geo Metro 1990

For 1990-2009 cars

# SMU - SECTION 6E2 - C7 - DRIVEABILITY & EMISSIONS

#### SUBJECT: SERVICE MANUAL UPDATE - SECTION 6E2-C7 - DRIVEABILITY AND EMISSIONS - EXHAUST GAS RECIRCULATION (EGR) PRESSURE TRANSDUCER (MODULATOR) CHECK

#### MODELS: 1989-1994 GEO METRO WITH 1.0L ENGINE (VIN 6)

THE FOLLOWING PROCEDURE REPLACES THE ONE ORIGINALLY PUBLISHED IN THE SERVICE MANUAL.

EXHAUST GAS RECIRCULATION (EGR) PRESSURE TRANSDUCER (MODULATOR) CHECK

1. REMOVE THREE VACUUM HOSES FROM THE EXHAUST GAS RECIRCULATION (EGR) PRESSURE TRANSDUCER (MODULATOR).

2. PLACE FINGER OVER EGR PRESSURE TRANSDUCER TUBE AND BLOW INTO OPPOSITE TUBE, SEE FIGURE 1 (PICTURE IN SERVICE MANUAL DID NOT CHANGE). AIR SHOULD PASS THROUGH FILTER PART OF PRESSURE TRANSDUCER.

3. CONNECT VACUUM PUMP TO TUBE "P" AND PLUG TUBE "Q" WITH YOUR FINGER, SEE FIGURE 2 (PICTURE IN SERVICE MANUAL DID NOT CHANGE).

4. BLOW AIR INTO TUBE "A" WHILE APPLYING VACUUM TO TUBE "P" AT THE SAME TIME. YOU SHOULD BE ABLE TO OBTAIN VACUUM ON THE VACUUM PUMP GAGE.

5. STOP BLOWING AIR INTO TUBE "A" AND VACUUM PUMP GAGE SHOULD INDICATE ZERO.

IF EGR PRESSURE TRANSDUCER FAILS EITHER TEST, REPLACE THE EGR PRESSURE TRANSDUCER.

FIGURES: 02 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. COPYRIGHT 1994 GENERAL MOTORS CORPORATION. ALL RIGHTS RESERVED.