Test M: Oil Pressure Warning Light Never/Always On

Manually check engine oil pressure. See appropriate article in ENGINES section. If oil pressure is within specifications, go to next step. If oil pressure is not within specifications, repair engine mechanical problem as necessary. See appropriate ENGINES article in the ENGINES section.
NOTE: If oil pressure warning light is always on, go to step 3).
Remove instrument cluster. See INSTRUMENT CLUSTER in REMOVAL & INSTALLATION. Remove oil pressure warning light bulb. Test continuity of bulb. Replace bulb if necessary. Retest system. If bulb is okay, go to next step.
Turn ignition off. Disconnect oil pressure sensor connector. Measure resistance between ground and oil pressure sensor connector. If resistance is less than 5 ohms with engine running and more than 10 k/ohms with engine off, go to next step. If resistance is 5 ohms or more with engine running or 10 k/ohms or less with engine off, replace oil pressure sensor. Retest system.
Disconnect instrument cluster connector C266. Measure resistance of Red wire between oil pressure sensor connector and instrument cluster connector C266 terminal No. 9. See Figure - Figure . Resistance should be less than 5 ohms. Measure resistance between ground and instrument cluster connector C266 terminal No. 9 (Red wire). Resistance should be more than 10 k/ohms. If resistance measurements are as specified, replace instrument cluster printed circuit. See PRINTED CIRCUIT under REMOVAL & INSTALLATION. Retest system. If resistance measurements are not as specified, repair Red wire. Retest system.