The purpose of this test is to evaluate the correct operation of an inductive camshaft sensor based on the output voltage and frequency with the engine at idle speed.
Technicians should whenever possible gain access to the test circuit without damage to seals and insulation. If this is not possible then make sure appropriate repairs are completed.
General connection advice.
PicoScope offer a range of options within the test kits.
Dependent on difficulty of access, choose from,
Testing sensors and actuators
(in order to include the relevant harness and connectors).
One complete sinewave is produced each time a tooth on the camshaft trigger wheel passes across the permanent magnet inside the sensor. In this example you will see x2 sine waves, however this is the same trigger passing the sensor twice, 720° camshaft rotation.
The induced AC voltage is quite low at just over 1 V, which is normal at idle speed.
This sensor can also be referred to as the Cylinder Identification (CID) sensor. It is essentially a magnetic pick up sensor. The function of which is to provide the ECM with a signal to identify the rotational position of the engine.
The data is used for a number of engine functions.
It is unlikely that a faulty sensor will prevent engine start but it may cause starting difficulties such as extended cranking. It will register a Diagnostic Trouble Code (DTC), with the possibility of the engine indicator lamp coming on.
List of Camshaft Sensor related generic DTC's.
P0010 A camshaft position actuator circuit (bank 1)
P0011 A camshaft position - timing over advanced or system performance (Bank 1)
P0012 A camshaft position - timing over retarded (Bank 1)
P0013 B camshaft position - actuator circuit (Bank 1)
P0014 B camshaft position - timing over advanced or system performance (Bank 1)
P0015 B camshaft position - timing over retarded (Bank 1)
P0016 - Crankshaft position Camshaft Position Correlation Bank 1 Sensor A
P0020 A camshaft position actuator circuit (Bank 2)
P0021 A camshaft position - timing over-advanced or system performance (Bank 2)
P0022 A camshaft position - timing over retarded (Bank 2)
P0023 B camshaft position - actuator circuit (Bank 2)
P0024 B camshaft position - timing over advanced or system performance (Bank 2)
P0025 B camshaft position - timing over retarded (Bank 2)
A faulty camshaft position sensor can also cause the engine to go into emergency mode.
The causes of failure can be mechanical as well as any physical circuit damage. Being a permanent magnet, the sensor will pick up any metal debris, although this is more likely at the crankshaft sensor due to its location.
The signal generated is quite weak and some sensors use cable shielding to prevent electrical noise interference. The air gap between sensor and signal wheel is also critical for good operation.
This help topic is subject to changes without notification. The information within is carefully checked and considered to be correct. This information is an example of our investigations and findings and is not a definitive procedure. Pico Technology accepts no responsibility for inaccuracies. Each vehicle may be different and require unique test settings.
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