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ABS Speed Sensor
Air Flow Meter / Sensor
Air Intake Pressure Sensor
Alternator Current and Voltage
Amplifier Earth
Camshaft Sensor
Carbon Canister Solenoid Valve
Crankshaft sensor
Coolant Temperature sensor
Diesel Glow Plugs
Digital ECM to Ignition Amplifier Signal
Distributor Pickup
Dual Trace
Electronic Fuel Pump
Exhaust Gas Recirculation
Idle Speed Control Valve
Injectors
Knock Sensor
Lambda Sensor
MAP Sensor
Primary
Relative Compression
Secondary
Supercharger
Throttle
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Camshaft Sensor - Inductive Diagnostics.
(scroll for Camshaft Sensor - Hall Effect and Camshaft Sensor - BoschCRD)

The camshaft sensor is sometimes referred to as the Cylinder Identification (CID) sensor or a 'phase' sensor and is used as a reference to time the sequential fuel injection by the Electronic Control Module (ECM).

This particular type of sensor generates its own signal and therefore does not require a voltage supply to power it. It is recognisable by its two electrical connections, with the occasional addition of a coaxial shielding wire.
The voltage produced by the camshaft sensor will be determined by several factors, these being the engine's speed, the proximity of the metal rotor to the pick-up and the strength of the magnetic field offered by the sensor. The ECM needs to see the signal when the engine is started for its reference; if absent it can alter the point at which the fuel is injected. The driver of the vehicle may not be aware that the vehicle has a problem if the CID sensor fails, as the drivability may not be affected.

Technical Information.


It is unlikely that a failed camshaft position sensor will cause the engine not to start, as this particular sensor only times the injector pulses. When this sensor is disconnected the point at which the injector fires can be seen to 'shift' giving an incorrect point at which the fuel is delivered behind the inlet valve.

This shows a typical camshaft position sensor.




Camshaft Sensor - Hall Effect Diagnostics


The camshaft sensor is sometimes referred to as the Cylinder Identification (CID) sensor and is used as a reference to time the sequential fuel injection. The signal waveform can be either a permanent magnetic sine wave or in this particular case a digital square wave.

The Electronic Control Module (ECM) needs to see the signal when the engine is started for its reference; if absent, it can put the ECM into 'limp-home'.

The characteristics of a good Hall effect waveform is clean, sharp switching and as with all other Hall units has 3 electrical connections.
Technical Information.

This sensor can also be referred to as the Cylinder Identification (CID) sensor. As the engine rotates the sensor will signal to the Electronic Control Module (ECM) that the engine is approaching number 1 and the timing of the injection pulse can be determined. On an inductive sensor, a resistance value should be seen between its terminals with these terminating back at ECM. The output signal from these units can be in either analogue or digital format (sine wave or square wave) and will depend on the manufacturer concerned. Vauxhall have also used a Alternating Current (AC) excited sensor on their Simtec engine management system, which is described later in this section.


This shows the camshaft position sensor in place.


Camshaft Sensor - BoschCRD Diagnostics.

The camshaft sensor is sometimes referred to as the Cylinder Identification (CID) sensor and is used as a reference to time the sequential fuel injection. The Electronic Control Module (ECM) needs to see the signal when the engine is started for its reference; if absent, it can put the ECM into 'limp-home'.

The characteristics of a good Hall effect sensor is clean, sharp switching and as with all other Hall units has 3 electrical connections.
Technical Information

The crank angle sensor described in the section above will define the position of the piston but its the camshaft sensor that informs the ECM of the cycle that the cylinder is on.

The sensor is mounted on the end of the camshaft.

The voltage is dependant on the position of the rotating disc (or target) mounted onto the camshaft.

The air gap between the sensor and the rotating disc is pre-set during production by a small plastic lug on the end of the sensor. The sensor is installed as far as possible and when the engine starts the lug breaks off, leaving the required air gap of 1.2 mm.