P0018

DTC P0018 CRANKSHAFT POSITION - CAMSHAFT POSITION CORRELATION (BANK 2 SENSOR A)

CIRCUIT DESCRIPTION

DTC Detection Condition:

The crankshaft position sensor system consists of a crankshaft position sensor plate and a pick up coil. The sensor plate has 34 teeth and is installed on the crankshaft. The pick up coil is made of an iron core and magnet. The sensor plate rotates and as each tooth passes through the pick up coil, a pulse signal is created. The pick up coil generates 34 signals for each engine revolution. Based on these signals, the ECM calculates the crankshaft position and engine RPM. Using these calculations, the fuel injection time and ignition timing are controlled.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

The ECM optimizes the valve timing using the Variable Valve Timing (VVT) system to control the intake valve camshaft. The VVT system includes the ECM, the Oil Control Valve (OCV) and the VVT controller. The ECM sends a target "duty-cycle" control signal to the OCV. This control signal, applied to the OCV, regulates the oil pressure supplied to the VVT controller. The VVT controller can advance or retard the intake valve camshaft. The ECM calibrates the valve timing of the VVT system by setting the camshaft to the maximum retard angle when the engine speed is idling. The ECM closes the OCV to retard the cam. The ECM stores this valve as "VVT learned value" (When the difference between the target valve timing and the actual valve timing is 5 degrees or less, the ECM stores this in its memory).

If the learned value meets both of the following conditions ("a" and "b"), the ECM interprets this as a defect in the VVT system and sets a DTC.
a. "VVT learning" value is less than 21-CA (Camshaft Angle) or more than 40 °CA.
b. Above condition continues for more than 18 seconds.

Wiring Diagram:

Step 1:

INSPECTION PROCEDURE

HINT: Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.