The purpose of this test is to evaluate the correct operation an AC excited camshaft sensor based on the AC voltage supply and AC voltage return signal during engine run conditions.
Connection for diagnostic work will of course vary dependent on application.
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 offers a range of options within the test kits.
Dependent on difficulty of access, choose from,
Testing Sensors and Actuators; (to include relevant circuit/connectors).
The sensor has three wires, one carrying the AC voltage input signal, a second the AC voltage output signal and a third earth cable.
This type of sensor is used on some of the GM/Vauxhall/Opel ECOTEC engines. This Cylinder Identification (CID) sensor differs in operation from the other inductive sensors by having an Alternating Current (AC) voltage supply to the CID sensor. The Electronic Control Module (ECM) supplies a high frequency of 100 to 150 kHz (100,000 to 150,000 cycles per second) to an exciter coil that is located close to a rotating disc.
The disc is located at the end of the camshaft and has a section removed that, when aligned with the sensor, allows the frequency to excite the receptor (through mutual inductance) and returns the signal to the ECM, indicating the position of number 1 cylinder.
As the frequency is so fast, the time scale should be set to 20us/division so that the oscilloscope can capture the frequency.
The CID sensor is used as a reference by the ECM to determine the camshaft's position, from which the correct timing for the sequential fuel injection can be determined.
This camshaft sensor differs in operation from the other sensors by having an Alternating Current (AC) voltage supply. The ECM supplies a high frequency of around 100 to 150 kHz to an exciter coil that is located close to a rotating disc.
The disc is located at the end of the camshaft and has a section removed that, when aligned with the sensor, allows the frequency to excite the receptor (through mutual inductance). The signal returns to the ECM, indicating the position of number 1 cylinder.
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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