Oil Pressure Gauge - Readings are Incorrect or Erratic

BULLETIN NUMBER:
93-8C-28

SECTION:
8C

NUMBER:
2

CORPORATE
REFERENCE NUMBER:
268304

DATE:
November 1992



SUBJECT:
INCORRECT OR ERRATIC OIL PRESSURE READINGS (INSTALL NEW [1][2]OIL PRESSURE SENSOR)

MODELS:
1990-93 ALL LIGHT DUTY MODELS



Owners of some 1990-93 light duty trucks may comment that the oil pressure dash gauge reads high, has erratic movement or is inoperative.

The internal resistance wire in the [1][2]oil pressure sensor may not be properly supported, resulting in an intermittent open condition.

SERVICE PROCEDURE
Check for normal causes of high oil pressure gage readings (high resistance or open circuit), such as a poor ground path caused by loose sensor mounting, oil cooler adapter loose, or poor electrical connections. If no cause can be found, replace the [1][2]oil pressure sensor following the procedure.



1. Disconnect the negative battery cable.

2. Remove the wiring harness connector from the [1][2]oil pressure sensor.

3. Remove the [1][2]oil pressure sensor.

4. Install the new [1][2]oil pressure sensor.

5. Connect the wiring harness connector to the [1][2]oil pressure sensor.

6. Connect the negative battery cable.

PARTS INFORMATION





New [1][2]Oil Pressure Sensor Part Numbers for the 1990-93 models



Parts are currently available from GMSPO

WARRANTY INFORMATION
For vehicles repaired under warranty use labor operation N2220.