Camshaft Position Sensor: Testing and Inspection

Component locations, refer to "Component Locations, Overview". Locations
The camshaft position sensor transmits the ignition position for cylinder 1.
During failure, the knock sensor is switched off and the ignition angle is retarded, because a cylinder assignment is no longer possible. In addition, the charge pressure of the turbocharger is lowered.

Without a camshaft position sensor, the engine will continue to run and can also be started:
- During malfunction recognition, the engine control module sets off an ignition spark for each cylinder for each crank shaft rotation.
- For the fuel injection, being off by one crankshaft revolution has no noticeable effect. Fuel is injected against the closed intake valve, instead of taking place while the valve is open. The quality of the fuel/air mixture is not significantly affected.

Checking activation
- Where installed, pull back boot from connector for camshaft position sensor, but leave connector connected.





- Connect voltage tester V.A.G. 1527 B between terminal 2 (camshaft position sensor signal) and socket 1 (B+).

NOTE: On the rear side of the connector the connector sockets are numbered accordingly.

- Operate starter several seconds.
- LED must blink

NOTE: Voltage testers with low current pickup do not extinguish completely between activation of the engine control module, but remain dimly lit and become noticeably brighter during activation.

If LED does not blink:

Checking voltage supply
- Disconnect connector from camshaft position sensor.





- Connect multimeter for a resistance test as follows:

Harness connector terminal Measure to
1 Engine Ground

- Turn ignition on.
- Specification: approx. 5 V

Checking signal wire
- Connect multimeter for a resistance test as follows:

Harness connector terminal Measure to
2 Engine Ground

- Turn ignition on.
- Specified value: approx. battery voltage

Checking Ground wire





- Check the following wire connections for open circuit and short circuit to B+:

Harness connector terminal Measure to
3 Engine Ground (GND)

- Repair open circuit or short circuit if necessary.
If all the specified values are reached and the diode does not blink (measured between terminals 1 and 2 with starter with connector connected):
- Replace camshaft position sensor.

If specified values are not obtained:

Checking wire connections between camshaft position sensor and engine control module
- Connect test box V.A.G 1598/31 at wiring harness to engine control module, the engine control module is not to be connected.





- Check the following wire connections for open circuit and short circuit between Ground (GND) and B+:

Harness connector Test box V.A.G 1598/31
terminal socket
1 (B+) 98
2 (Signal) 86
3 (Ground) 108

- Repair open circuit or short circuit if necessary.
- If after erasing DTC memory another malfunction regarding the camshaft position sensor is displayed, even though all tests to this point were OK, the following malfunction is possible:
- Impulse wheel for camshaft position sensor is out of adjustment
- Remove camshaft position sensor and check if the impulse wheel is properly installed (if incorrectly assembled, the locking nose is flattened when the bolt is tightened).
- If the position of the impulse wheel is OK, check alignment of crankshaft to camshaft.