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DTC - Diagnostic Trouble Codes information

P0023

Powertrain Codes

P0023 - TOYOTA - Camshaft Position 'B' Actuator Circuit Bank 2

Symptoms

- Engine Light ON (or Service Engine Soon Warning Light) - Lack/Loss of power - Engine rough idle

Possible Causes

- Dirty Oil - Variable Valve Timing (VVT) circuit is open or shorted - Oil Control Valve (OCV) circuit is open or shorted - Faulty variable valve timing (VVT) - Faulty oil control valve (OCV) - Damaged ECM

When Detected

After the ECM sends the target duty cycle signal to the OCV, the ECM monitors the OCV current to establish an actual duty cycle. The ECM determines the existence of a malfunction and sets the DTC when the actual duty cycle ratio varies from the target duty cycle ratio.

Tech Notes

If the engine oil is clean and the VVT and OCV circuits are OK, replaced the VVT to resolve the problem.

Description

The Engine Control Module (ECM) controls the Oil Control Valve (OCV) to regulate the intake camshaft angle. As a result of the angle change, the engine timing is advance or retard. Optimizing engine timing will help the engine improve torque and fuel economy, and the exhaust emissions decrease under overall driving conditions. The Variable Valve Timing (VVT) system includes the Oil Control Valve (OCV) and VVT controller. The ECM detects the actual intake valve timing using signals from the camshaft and crankshaft position sensors, and performs feedback control.