Oil Control Valve Operation (GS400, LS400 & SC400)

Each cylinder head has one OCV located in front inside corner of cylinder head. Remove engine cover. Remove intake air connector pipe, if necessary. Remove throttle body. See THROTTLE BODY under FUEL SYSTEM in REMOVAL, OVERHAUL & INSTALLATION article. Remove Oil Control Valve (OCV) to be tested. Connect a fused jumper wire between battery voltage and terminal No. 1 at OCV. See Fig 1.
Connect another jumper wire between negative battery terminal and terminal No. 2 at OCV and note OCV plunger operation. With battery voltage applied, plunger on end of OCV should extend. Disconnect a jumper wire. Without battery voltage applied, plunger should retract. If OCV operation is not as specified, replace OCV.

Fig 1: Testing Camshaft Timing Oil Control Valve