B131 and/or B132 Engine Oil Pressure Circuit Problem

Code B131 And/Or B132 - Engine Oil Pressure Circuit Problem:

Wiring Diagram for Code B131 And/Or B132 - Engine Oil Pressure Circuit Problem:

CODE B131 AND/OR B132 - ENGINE OIL PRESSURE CIRCUIT PROBLEM

Circuit Description:

The oil pressure gage uses a variable resistor to control the signal voltage to the BCM. The BCM supplies a voltage on CKT 313 to the sensor. When the engine is not running (low oil pressure) the sensor's resistance is low and the signal voltage is pulled Lo through sensor ground, CKT 736. When the engine is running (increased oil pressure) the sensors resistance becomes greater and the signal voltage increases, therefore the BCM will see a Hi signal voltage (open CKT). This signal voltage will vary between 5V (open CKT) and OV (shorted CKT).

Code B131 will set with key "ON" engine not running if the signal voltage indicates greater than 8 psi (open CKT). Code B132 will set if the engine is running and the signal voltage indicates greater than 80 psi (open CKT).


Test Description:

1. If only Code B131 is set the sensor is off and needs replacement.

2. BCM data value BD71 displays oil pressure. The normal range is from 0 to 80 PSI.

3. Checks to see if the open circuit reading is due to the circuit or sensor. If the open circuit reading changes to a shorted circuit reading after jumpering the sensor terminals, the BCM and wiring are OK.

4. By applying a ground to various points in the circuits, an open can be isolated by observingw hether the parameter display can be changed from the open reading to the shorted reading.


Note on Intermittents:

If an intermittent code B131 and/or B132 is being set, manipulate the related wiring while observing BCM data parameter BD71. If the failure is induced the reading will jump from 0 to some oil pressure with the engine off.