Camshaft position sensor for 1.0L, 37 kW and 1.4L, 50 kW engines
1 – junction block; 2 – sensor
The camshaft position sensor sends a signal to the engine control unit about the ignition timing in the first cylinder. If the sensor fails, the control unit switches to a backup program, in which the ignition timing is slightly reduced and a spark between the spark plug electrodes jumps simultaneously in all four cylinders with each revolution of the crankshaft.
Examination
1. Disconnect connector 1 (see figure Camshaft position sensor for 1.0 l, 37 kW and 1.4 l, 50 kW engines) with wires from camshaft position sensor 2.
2. Turn on the ignition. Connect a voltmeter to pins 1 and ground of the sensor's connector block, then to pins 2 and ground. In both cases, the voltmeter should read approximately 5 V.
3. Then connect the voltmeter to terminals 3 of the connector and the "+" terminal of the battery. The voltmeter should show the battery voltage.
4. Otherwise, check the wires for open circuits and short circuits.
5. If there is no open or short circuit in the wires and the voltmeter shows the voltage indicated above, replace the camshaft position sensor.
6. If there is no open or short circuit in the wires, and the voltmeter shows 0, replace the engine control unit.