For 1990-2009 cars

# SERVICE MANUAL UPDATE-SEC 8A OIL PRESSURE INDICATOR GAUGE

THIS BULLETIN IS AN INFORMATIONAL UPDATE ON A 1992 1/2 ENGINEERING CHANGE, ON THE 1992 U-VAN APV'S OIL PRESSURE INDICATOR GAUGE SENDER.

THE CHANGE AFFECTS THE 1992 1/2 SILHOUETTE, TRANS SPORT, AND LUMINA APV'S. THE OIL PRESSURE GAUGE, FOR THE 3.1L (VIN D) ENGINE, WAS PREVIOUSLY FED BY A VARIABLE RESISTANCE OIL PRESSURE SENDER. THE VARIABLE RESISTANCE SENDER HAS BEEN CHANGED TO A TWO POSITION OIL PRESSURE SWITCH, ON THE 3.1L (VIN D) ENGINE. THE TWO POSITION OIL PRESSURE SWITCH HAS A 68 OHM RESISTOR IN PARALLEL WITH IT.

THIS ENGINEERING CHANGE WILL CREATE A FUNCTIONAL CHANGE IN THE OPERATION OF THE OIL PRESSURE GAUGE. THE OIL PRESSURE GAUGE WILL SHOW A 3/4 SCALE READING DURING NORMAL ENGINE RUN CONDITIONS, ON THE 3.1L (VIN D) ENGINE. IT IS NORMAL FOR THE OIL PRESSURE GAUGE TO STAY AT A 3/4 SCALE READING, WITH THE IGNITION SWITCH IN THE "OFF" POSITION.

THE ENCLOSED PAGES REFLECT THE CHANGES IN THE SCHEMATICS, DIAGNOSTIC CHARTS, AND THE CIRCUIT OPERATION. THIS BULLETIN IS BEING CONVEYED TO KEEP OUR CAR DEALERS AND CUSTOMERS INFORMED.

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 1992 GENERAL MOTORS CORPORATION ALL RIGHTS RESERVED