LEMON Manuals: Even more car manuals for everyone
Home >> Toyota >> 2001 >> Sienna CE >> Repair and Diagnosis >> External Pages >> Different car >> Section 17 (Engine Control System Self-Diagnostics - 4-Cylinder) >> Diagnostic Tests >> DTC P1656: Oil Control Valve Malfunction >> Diagnosis & Repair (Without Toyota Hand-Held Tester)

Diagnosis & Repair (Without 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.
  1. Start engine and allow it to idle. Disconnect Variable Valve Timing (VVT) Oil Control Valve (OCV) harness connector and note idle speed. OCV is located in cylinder head, at timing chain side of engine. VVT OCV is located on timing chain side of cylinder head. Engine idle speed should not change. Using jumper wires, apply battery voltage and ground to VVT OCV. Engine should idle rough or stall. If VVT OCV operates as specified, go to next step. If VVT OCV does not operate as specified, replace VVT OCV.
  2. Turn ignition off. Connect VVT OCV harness connector. 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 Figure. 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.
  3. Check for an open or short in wiring between VVT OCV and ECM. If problem exists, repair wiring as necessary. If problem does not exist, problem is intermittent. Check component and ECM connections.
scientia non olet · About LEMON Manuals