Code Definition
- DTC P0010: Camshaft Position "A" Actuator Circuit (Bank 1)
- DTC P0020: Camshaft Position "A" Actuator Circuit (Bank 2)
| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - LEXUS article in GENERAL INFORMATION. |
Circuit Description
VVT system controls intake camshaft to provide optimal valve timing for every driving condition. This control is performed based on signals of conditions such as intake air volume, throttle position and engine coolant temperature. ECM controls Oil Control Valve (OCV), based on signals output from sensors. VVT controller regulates intake camshaft angle using oil pressure through OCV. As a result, relative positions of camshaft and crankshaft become optimal. Engine torque improves, fuel economy improves and exhaust emissions decrease under overall driving conditions. Also, ECM detects actual valve timing using signals from camshaft position sensor and crankshaft position sensor, and performs feedback control. This is how target valve timing is achieved by ECM. (Scheme 171) If DTC is set, an open or short is present in oil control valve assembly circuit, camshaft timing oil control valve assembly, and/or ECM.
Scheme 171
Diagnostic Aids
If DTC P0010 is displayed, check right bank VVT system circuit. If DTC P0020 is displayed, check left bank VVT system circuit. Read freeze frame data using hand-held tester or OBD-II scan tool, as freeze frame data records engine conditions when a malfunction is detected. When troubleshooting, it is useful to determine whether vehicle was running or stopped, engine was warmed up or not, air-fuel ratio was lean or rich, etc. at time of malfunction.