Diagnosis & Repair (Using Toyota Hand-Held Tester)
WARNING: This page is about a different car, the 2002 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.
- Check valve timing. See appropriate article in ENGINES. If problem exists, repair as necessary. If problem does not exist, go to next step.
- Start engine and warm to normal operating temperature. Connect hand-held tester to Data Link Connector (DLC) No. 3. See Figure. Using hand-held tester, select ACTIVE TEST mode. Select VVT. Note idle speed when VVT OCV is activated by hand-held tester. Idle speed should be normal with VVT OCV off, and engine should idle rough or stalls when VVT OCV is on. If idle speed does not function as specified, go to next step. If idle speed functions as specified, 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.
- Turn ignition off. Access ECM behind glove box. See Figure. Using oscilloscope, backprobe ECM harness connector and connect oscilloscope between terminals No. 19 (Green/White wire) and No. 29 (Yellow/Red wire) at ECM harness connector E9. See Figure. Start engine and let idle. Ensure oscilloscope pattern is as shown in illustration. 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.
- Turn ignition off. Check VVT controller assembly for proper operation. See appropriate article in ENGINES. If problem does not exist, go to next step. If problem exists, replace VVT controller assembly and go to next step.
- Disconnect VVT OCV harness connector. Measure resistance between VVT OCV terminals (component side). Resistance should be 6.9-7.9 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace VVT OCV.
- Remove VVT OCV. Connect a fused jumper wire between positive battery terminal and terminal No. 1 at VVT OCV. See Fig 2. Connect another jumper wire between negative battery terminal and terminal No. 2 at VVT OCV and note VVT OCV plunger operation. With battery voltage applied, plunger on end of VVT OCV should extend. Disconnect a jumper wire. Without battery voltage applied, plunger should retract. If VVT OCV does not operate as specified, replace VVT OCV and go to next step. If VVT OCV operates as specified, go to next step.
- Check blockage in VVT OCV. Check oil check valve and oil pipe located under VVT OCV. If problem does not exist, go to next step. If problem exists, repair as necessary.
- Install all remove components and connect all disconnected harness connectors. Using hand-held tester, clear DTCs. Start engine and allow it to idle. Turn ignition off. Turn ignition on and check for DTCs. If DTC P1349 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 is present, replace ECM.