OIL PRESSURE GAUGE READING CONCERNS. GMC Truck S15 Pickup

REVISION: 12/09/94

THIS BULLETIN IS BEING REVISED TO CHANGE MODEL YEARS FOR OLDSMOBILE BRAVADA. ----------------------------------------------------------------------

SUBJECT: OIL PRESSURE GAUGE READING CONCERNS (REPLACE OIL PRESSURE SENDING UNIT)

MODELS: 1991-94 CHEVROLET AND GMC TRUCK C/K, S/T AND P TRUCKS, M/L AND G VANS 1991-92 OLDSMOBILE BRAVADA WITH 2.2L, 4.3L, 5.0L, 5.7L, 7.4L ENGINES (VINS 4, Z, H, K, N - RPOS LN2, LB4, L03, L05, L19)

CONDITION:

SOME OWNERS MAY COMMENT ON ONE OR ALL OF THE FOLLOWING CONDITIONS:

* HIGH OIL PRESSURE WHEN STARTING ENGINE COLD. * LOW OIL PRESSURE WHEN ENGINE IS AT IDLE HOT. * ERRATIC GAUGE READINGS.

CAUSE:

OIL PRESSURE SENDING UNIT WAS NOT OPTIMALLY CALIBRATED FOR ALL OPERATING CONDITIONS.

CORRECTION:

IF ACTUAL OIL PRESSURES ARE WITHIN TOLERANCES LISTED IN SECTION 6A OF THE SERVICE MANUAL, AND GAUGE CIRCUIT ELECTRICAL DIAGNOSTICS IN SECTION 8C OF THE SERVICE MANUAL DO NOT UNCOVER THE SOURCE OF THE PROBLEM, A NEW OIL PRESSURE SENDING UNIT SHOULD BE INSTALLED.

PART INFORMATION:

DESCRIPTION PART NUMBER ----------- ----------- OIL PRESSURE SENDING UNIT 12553175

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE: LABOR OPERATION: N2220 USE PUBLISHED LABOR OPERATION AND TIME.

FIGURES: 0

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.