Code Definition
- DTC P0010: Camshaft Position "A" Actuator Circuit (Bank 1)
- DTC P0020: Camshaft Position "A" Actuator Circuit (Bank 2)
Note. For information on engine immobilizer system, see COMPUTERIZED ENGINE CONTROLS in THEORY & OPERATION article.
| 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. |
Circuit Description
The VVT system controls the intake camshaft to provide the optimal valve timing for every driving condition. This control is performed based on the signals and such conditions as intake air volume, throttle position and engine coolant temperature. The ECM controls the oil control valve (OCV), based on the signals output from the sensors. The VVT controller regulates the intake camshaft angle using oil pressure through the OCV. As a result, the relative position between the camshaft and the crankshaft becomes optimal, and the engine torque improves, fuel economy improves, and exhaust emissions decrease under overall driving conditions. Also, the ECM detects the actual valve timing using the signals from the camshaft position sensor and the crankshaft position sensor, and performs feedback control. This is how target valve timing is achieved by the ECM. DTC is detected when there is an open or short in oil control valve circuit. (Scheme 37)and (Scheme 38). Possible causes are
- Open or short in oil control valve circuit.
- Faulty oil control valve.
- Faulty ECM.
Scheme 37
Scheme 38
Diagnostic Aids
If DTC P0010 is displayed, check the left bank VVT system circuit. If DTC P0020 is displayed, check the right bank VVT system circuit. Read freeze frame data using hand-held tester or OBD-II scan tool, as freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, or air-fuel ratio was lean or rich at the time of the malfunction.