Camshaft Position (CMP) Sensor
- Baja, Forester, Impreza, Legacy, Outback 2.5L & Outback Sport - The camshaft position sensor is located on the left camshaft support. It detects the combustion cylinder at any given moment. The sensor generates a pulse when one of the bosses on the back of the left camshaft drive sprocket passes in front of the sensor. The ECM determines the camshaft angular position by counting the number of pulses. Internal construction and the basic operating principle of the camshaft position sensor are similar to those of the crankshaft position sensor. Two bosses are provided on the sprocket for Impreza WRX 2.0L and a total of seven bosses are arranged at four equally spaced locations (one each at two locations, two at one location, and three at one location) of the sprocket for Forester, Impreza, Legacy, Outback 2.5L and Outback Sport.
- Outback 3.0L - The camshaft position sensor is located on the right cylinder head. It detects the combustion cylinder at any given moment. The sensor generates a pulse when one of the slots on the back of the right camshaft plate passes in front of the sensor. The ECM detects the camshaft position by measuring the pulse. Three slots are provided on the plate.
Fig 1: Identifying Camshaft Position Sensor, Bosses & Pulses (Baja, Forester, Impreza 2.5L, Legacy, Outback 2.5L & Outback Sport)