Test M: Low Oil Pressure Warning Indicator Inoperative/Always On

WARNING: This page is about a different car, the 2001 Mazda Tribute. However, it is still accessible from the selected car via links, so may be relevant.

Turn ignition switch to LOCK position. Disconnect oil pressure switch single pin harness connector. On Duratec models, oil pressure switch is located on right front side of engine. On Zetec models, oil pressure switch is located on right rear side of engine. Connect a 10-amp fused jumper wire between ground and oil pressure switch harness connector Dark Green/White wire terminal. Turn ignition switch to RUN position. If low oil pressure indicator illuminates, go to next step. If low oil pressure indicator does not illuminate, go to step 3 .

Disconnect oil pressure switch harness connector and remove oil pressure switch from engine. Connect engine oil pressure gauge and adapter. Run engine until normal operating temperature is reached. Run engine at specified RPM and record reading. See ENGINE OIL PRESSURE SPECIFICATION table. If engine oil pressure is within specification, go to step 5 . If engine oil pressure is not within specification, repair oil pressure concern. See appropriate ENGINES article in ENGINE, CLUTCH & DRIVE AXLE.

ENGINE OIL PRESSURE SPECIFICATION

Engine

RPM

PSI (k/pa)

2.0L Zetec

4000

⁽¹⁾ 54-80 (370-550)

3.0L

448

⁽¹⁾ 45 (310)

⁽¹⁾	Engine must be HOT for proper measurement.

Turn ignition switch to OFF position. Disconnect instrument cluster 18-pin harness connector C220c. See Figure . Measure resistance of Dark Green/White wire between instrument cluster harness connector C220c, terminal No. 17 and oil pressure switch harness connector. See Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Dark Green/White wire. See WIRING DIAGRAMS .
Turn ignition switch to RUN position. Measure voltage between ground and instrument cluster harness connector C220c, terminal No. 17 (Dark Green/White wire). If voltage does not exist, go to step 6 . If voltage exists, repair short to voltage in Dark Green/White wire. See WIRING DIAGRAMS .
Turn ignition switch to LOCK position. Disconnect instrument cluster 18-pin harness connector C220c. See Figure . Measure resistance between ground and instrument cluster harness connector C220c, terminal No. 17 (Dark Green/White wire). See Figure . If resistance is less than 5 ohms, repair short to ground in Dark Green/White wire. See WIRING DIAGRAMS . If resistance is 5 ohms or more, replace oil pressure switch.
Disconnect all instrument cluster harness connectors. Inspect for corrosion or pushed out pins. Connect all instrument cluster harness connectors. Operate system and verify if concern still exists. If concern still exists, replace instrument cluster. See INSTRUMENT CLUSTER under REMOVAL & INSTALLATION. If concern does not exist, system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.