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Home >> Toyota >> 2001 >> Sienna CE >> Repair and Diagnosis >> External Pages >> Different car >> Section 23 (Engine Control System Self-Diagnostics) >> Diagnostic Tests >> DTC P1656: Oil Control Valve Circuit Malfunction (Bank No. 1) Or DTC P1663: Oil Control Valve Circuit Malfunction (Bank No. 2) >> Diagnosis & Repair

Diagnosis & Repair

WARNING: This page is about a different car, the 2002 Toyota Sienna. However, it is still accessible from the selected car via links, so may be relevant.
    NOTE: DTC P1656 is for VVT OCV (bank No. 1) which is on the right bank and DTC P1663 is for VVT OCV (bank No. 2) which is on the left bank. It may be necessary to consult wiring diagram to verify wire colors so test procedures are performed on appropriate VVT OCV. See WIRING DIAGRAMS article. VVT OCVs are located on cylinder head. See Figure.
  1. If Toyota hand-held tester is available, go to next step. If Toyota hand-held tester is not available, go to step  4.
  2. Connect hand-held tester to Data Link Connector (DLC) No. 3 at driver's side of instrument panel. See Figure. Start engine and warm engine to normal operating temperature. Allow engine to idle.
  3. Select ACTIVE TEST mode and then VVT on hand-held tester to operate the appropriate VVT OCV. Note engine idle when VVT OCV is operated by hand-held tester. Engine idle should be normal with VVT OCV off and should become rough or engine may stall when VVT OCV is on. If engine idle does not function as specified, shut engine off. Go to next step. If engine idle is as specified, VVT OCV is functioning properly at this time. DTC may have been set due to intermittent problem in wiring harness or electrical connectors between ECM and appropriate VVT OCV.
  4. Disconnect electrical connector at appropriate VVT OCV. VVT OCVs are located on cylinder head. See Figure. Start engine and allow engine to idle. With engine idling, using jumper wires, apply battery voltage and ground to electrical terminals on appropriate VVT OCV. Engine should idle rough or stall. If VVT OCV operates as specified, shut engine off. Go to next step. If VVT OCV does not operate as specified, shut engine off. Replace VVT OCV. See VARIABLE VALVE TIMING CAMSHAFT TIMING OIL CONTROL VALVE under VARIABLE VALVE TIMING SYSTEM in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
  5. Reinstall electrical connector on appropriate VVT OCV. Remove glove box for access to ECM with electrical connectors still installed on ECM. See Figure. Connect oscilloscope between terminals No. 5 (Blue/Black wire) and No. 6 (Red/Black wire) at ECM electrical connector E12 for VVT OCV on right bank or terminals No. 18 (Black/White wire) and No. 29 (Red wire) at ECM electrical connector E12 for VVT OCV on left bank. SeeFigure. This is the OC1-, OC1+, OC2-, OC2+ terminals on ECM.
  6. Start engine and allow engine to idle. Ensure VVT OCV signal waveform pattern is as shown in illustration. See Figure. As engine speed is increased, waveform pattern frequency "A" should lengthen. If signal waveform pattern is as shown, shut engine off. Go to next step. If signal waveform pattern is not as shown, shut engine off. Replace ECM.
  7. Check for open and short in wiring harness and electrical connectors between appropriate VVT OCV and ECM. See WIRING DIAGRAMS article. If wiring harness and electrical connectors are okay, problem is intermittent. Check for defective connections or intermittent problem in wiring harness and electrical connectors between appropriate VVT OCV and ECM. If wiring harness or electrical connector is defective, repair as necessary.
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