Diagnosis & Repair (Using Lexus Scan Tool)
WARNING: This page is about a different car, the 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
- Check valve timing. See appropriate article in ENGINES. Repair as necessary. If valve timing is okay, go to next step.
- Using scan tool, select ACTIVE TEST mode. Note idle speed when OCV is activated by scan tool. If idle speed is normal with OCV off and engine idles rough or stalls when OCV is on, VVT is functioning properly at this time. DTC may have been set because of a foreign object that was temporarily caught in the engine oil system but after a short time system returned to normal. If idle speed does not function as specified, go to next step.
- With engine idling, check voltage to OCV. If checking OCV for bank No. 1 (right cylinder head), backprobing, connect oscilloscope between ECM E8 connector terminals No. 13 (Blue/White wire) and No. 14 (Blue/Red wire). See Figure. If checking OCV for bank No. 2 (left cylinder head), backprobing, connect oscilloscope between ECM E8 connector terminals No. 15 (Green/Red wire) and No. 16 (Green/Black wire). See Figure. On all applications, ensure oscilloscope pattern is as shown. See Fig 1. As engine speed is increased, waveform frequency ("A") should lengthen. If waveform pattern is as shown, go to next step. If waveform pattern is not as shown, replace ECM.
- Remove timing belt cover and timing belt. See appropriate article in ENGINES. Remove OCV. Place a shop towel under OCV cylinder head opening. Rotate VVT pulley from left to right about 30 degrees 2-3 times. Oil should drain from OCV cylinder head opening. If oil does not drain from opening, replace VVT pulley/gear assembly and go to next step. If oil drains from opening, go to next step.
- With OCV removed, connect a jumper wire between positive battery terminal and terminal No. 1 at OCV. See Fig 2. 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 operates as specified, go to next step. If OCV does not operate as specified, replace OCV and go to next step.
- Check for blockage in OCV. Check oil check valve and oil pipe located under OCV. Repair as necessary. If components are okay, go to next step.
- Clear DTCs. Start engine and allow it to idle. Turn ignition off. Turn ignition on and check for DTCs. If DTC P1349 or P1354 is not present, no problem is indicated at this time. DTC may have been set because of a foreign object that was temporarily caught in the engine oil system but after a short time system returned to normal. If DTC P1349 or P1354 is present, replace ECM and retest.