OIL PRESSURE INDICATING SYSTEM - DESCRIPTION AND OPERATION

** ON A/C NOT FOR ALL

1. General

A. The engine oil system has the indication and warning systems that follow:

Main oil pressure indicating system
Low oil pressure indicating system
Main oil temperature indicating system
Auxiliary oil pressure indicating system
Oil level indicating system
Oil filter differential pressure system
Oil debris monitoring system.

(1) These systems are used to monitor oil system conditions and signal the flight crew of possible problems.

(2) Components in the indicating systems send a signal to the Electronic Engine Control (EEC), which then sends the signal to the Electronic Centralized Aircraft Monitoring (ECAM) System.

** ON A/C NOT FOR ALL

2. Component Location

FIN	FUNCTIONAL DESIGNATION	ZONE	ATA REF
** ON A/C NOT FOR ALL
4070KS	SENSOR-PRESSURE, AUXILIARY OIL	400	73-11-00
4071KS	SENSOR-PRESSURE, MAIN OIL	400	73-11-00
4077KS	OIL FILTER DIFFERENTIAL PRESSURE SENSOR	400	74-11-51
4080KS	SW-LOW OIL PRESS	400	73-11-00

** ON A/C NOT FOR ALL

3. System Description

Oil Pressure Indicating System (MOP, LOP, Differential Pressure Sensor and AOP) ** ON A/C NOT FOR ALL

A. Auxiliary Oil Pressure (AOP) Sensor

(1) The AOP sensor is located on the Oil Control Module (OCM) at approximately the 9 o'clock position.

(a) The AOP sensor measures the pressure of the supply oil for the journal bearings of the Fan Drive Gearbox (FDG) to detect failures in the Journal Oil Shuttle Valve (JOSV) or the oil auxiliary pump.

(b) The sensor is installed on the oil manifold.

(d) The sensor has one electrical connector that sends a signal to both channels A and B of the EEC. The elements send signals independently over different channels.

(e) The AOP sensor is a line replaceable unit.

B. Main Oil Pressure (MOP) Sensor

(1) The MOP sensor is attached to the front of the OCM to the left of the main gearbox at approximately the 9 o'clock position.

(a) The MOP sensor is used to sense the pressure on the oil supply side of the lubrication system.

(b) The sensor is installed on the OCM.

(c) The sensor has one electrical connector and sends signals to both A and B channels of the EEC. The EEC then sends a signal to the ECAM for a flight deck display of engine oil pressure.

(d) The sensor contains two electrically-isolated sensor elements.

(e) The MOP sensor is a line replaceable unit.

C. Oil Filter Differential Pressure Sensor

(1) The oil filter differential pressure sensor is attached to the front of the oil pump at approximately the 8 o'clock position.

(a) The oil filter differential pressure sensor is installed on the OCM, adjacent to the oil filter.

(b) The sensor contains two electrically-isolated sensor elements.

(c) The sensor reads from two locations, one upstream and one downstream of the main oil filter element where differential oil pressure is monitored.

(d) The differential pressure signal is sent to both channels A and B of the EEC. When the differential pressure across the filter is more than the specified limit, a maintenance signal is sent.

(e) When the differential pressure across the primary oil filter element is too much, the filter bypass valve will open. Pressurized oil will go directly to the secondary filter. An oil filter bypass signal is also sent to the flight deck through the EEC.

(f) The oil differential pressure sensor is a line replaceable unit.

D. Low Oil Pressure (LOP) Switch

(1) The LOP switch is attached to the OCM to the left of the main gearbox at approximately the 8 o'clock position.

(a) The LOP switch is installed on the OCM on the supply side of the oil system, downstream of the MOP sensor.

(b) The switch is a one-channel switch that bypasses the EEC and sends a signal directly to the Engine Interface Unit (EIU) when low oil pressure is detected.

[Rev.10 from 2021] 2026.04.01 03:42:13 UTC