Camshaft Position Sensor: Testing and Inspection
The camshaft position sensor is located on the left rear of the cylinder head, refer to "Component Locations - I "Locations
Checking voltage supply
- Disconnect camshaft position sensor harness connector.
- Switch Fluke 83 multimeter to 20 volt range and connect between terminal 1 (B+) and terminal 3 (GND).
- Switch ignition on.
Specified value: min. 9 volts
If the specified value is not obtained:
- Check wiring for continuity or short between camshaft position sensor and ECM using wiring diagram.
- Connect VAG 1598/19 test box to ECM harness connector.
- Check camshaft position sensor Ground (GND) wire for continuity between connector terminal 3 and engine Ground.
Specified value: 1 ohm
- Check camshaft position sensor B+ wire for continuity between connector terminal 1 and test box socket A2.
- Specified value: max. 1 ohm
- Check both wires for possible short to each other.
If the specified values are not obtained:
- Check for open or short circuit in wiring between the camshaft position sensor connector and ECM connector -A- or engine Ground (GND), eliminate as necessary.
Camshaft position sensor ECM connector A terminal number
connector terminal number or engine ground (GND)
1 (B+) A2
3 (Ground) Engine Ground (GND)
If there is neither an open nor short circuit:
- Replace ECM.
Function, checking
NOTE: For functional check of camshaft position sensor, disconnect the 4-pin connector from the ignition coil power output stage and check DTC memory.
- Camshaft position sensor voltage supply OK. See "Checking voltage supply".
- Push back rubber boot on camshaft position sensor connector (sensor remains connected).
- Connect VAG 1527B voltage tester between terminal 1 (B+) and 2 (signal).
- Operate starter for several seconds.
- Voltage tester must flash briefly every second engine rotation
If voltage tester does not flash:
- Switch ignition off and disconnect 3-pin harness connector from camshaft position sensor.
- Connect VAG 1598/19 test box to ECM harness connector.
- Check signal wire for continuity between harness connector terminal 2 and test box socket B2.
Specified value: max. 1 ohm
If the specified value is not obtained:
- Eliminate short or open circuit in wiring between camshaft position sensor harness connector...
...and ECM harness connector -B-.
Camshaft position sensor ECM connector A terminal number
connector terminal number or engine ground (GND)
2 (signal) 8
If wiring is OK:
- Connect Fluke 83 multimeter between test box socket B2 and vehicle Ground (GND).
- Switch ignition on.
Specified value: min. 4.0 volts
If the specified value is not obtained:
- Replace ECM.
If the specified value is obtained:
- Replace Camshaft Position (CMP) sensor.