ALTROZ SERVICE MANUAL

1.2L REVOTRON ENGINE 155 III. Camshaft Position Sensor :  Component Details : A typical Hall Effect Sensor has three wires or terminals: one for ground, one for supply or reference voltage and one for the output signal. To produce an output signal, a Hall Effect Sensor must be supplied with a reference voltage. When a metal/wheel passes through the air gap between the magnetic field (Magnet) and silicon chip (CAM sensor), it blocks the magnetic field and causes the chip’s output voltage to suddenly drop to zero else the chip's output voltage is 4.7 Volts.  Component Location : The cam phase sensor is mounted on cylinder head.  Preliminary Checks : 1. Loose / Damaged connections between sensor and EMS ECU. 2. Check for back out of pins at both sensor connector and ECU connector. 3. Check for damage of pins at both sensor connector and ECU connector. 4. Check the continuity from sensor connector pins to the ECU pins. 5. Physical damage to Cam target wheel. 6. Improper air gap between sensor and cam target wheel.  Connector View :  Connector Details : Connector Description 1 Ground (-) 2 Signal 3 Supply (+)  Component Specification : Cam Shaft sensor measures the speed of the CAM shaft. The cam phase sensor is mounted on cylinder head cover, with a gap of 1.0± 0.5mm between cylinder head cover surface and sensor tip. The sensor provides input signal to ECU to determine the phase, i.e. the sensor provides signal voltage when the target wheel passes through the sensor. The position of target wheel indicates the engine phase. Cam shaft sensor contains a permanent magnet and a Hall IC. Due to the rotation of a ferromagnetic target wheel in front of Sensor, the magnetic field is modulated at the place of the hall probe. With a tooth in front of the sensor, the magnetic field increases, with a slot it decreases. This modulation results in changes of the output signal. The magnetic field is evaluated by the hall probe in the ASIC.  Sensor Stand alone Diagnosis : With ignition key is 'ON' position, use multimeter to measure the supply voltage across pin1 and pin3, which should be 12V DC. Measure the signal voltage across pin1 and pin2.