With Generic Scan Tool

Camshaft Position (CMP) Sensor -G40-, Checking

Recommended special tools and equipment







- VAG1526A hand multimeter
- V.A.G 1527 B Voltage Tester
- VAG1594A connector test kit
- VAG1598/31 test box

Test requirement:
- Ignition switched off.

Checking activation
- If installed, slide back rubber grommet from connector for Camshaft Position (CMP) sensor.







- Connect voltage tester e.g. V.A.G 1527 B with measuring probes and connector adapters from V.A.G 1594 A between socket 2 (CMP sensor signal) and socket 1 (B+); the harness connector remains connected.


NOTE: Connector sockets are numbered respectively on the rear side of the connector.


- Operate starter for a few seconds.
- LED must blink.


NOTE: Voltage testers do not go out completely during low current pick-up between activations by the ECM, but rather continue to glow a little and then get significantly brighter during activation.


- Switch ignition off.

If LED does not blink:

Checking voltage supply







- Disconnect harness connector (arrow) from Camshaft Position (CMP) Sensor -G40-.







- Connect multimeter for voltage measurement as follows:

Harness connector Terminal Measure to
1 Engine Ground (GND)

- Switch ignition on.
- Specified value: about 5 V

- Switch ignition off.

Checking signal wire







- Connect multimeter for voltage measurement as follows:

Harness connector Terminal Measure to
2 Engine Ground (GND)

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

- Switch ignition off.

Checking Ground (GND) wire







- Connect multimeter for voltage measurement as follows:

Harness connector Terminal Measure to
3 B+

- Specified value: about 10 V

If all specified values are being reached and the LED does not blink (measured between terminal 1 and 2 with starter and connector connected):
- Replace Camshaft Position (CMP) sensor.

If specified values are not obtained:

Checking wire connections between Camshaft Position (CMP) sensor and Engine Control Module (ECM)
- Connect test box to wiring harness of Engine Control Module (ECM); ECM is not connected. Test Box, Connecting For Wiring Test







- Check the following wire connections for open circuit according to wiring diagram:

Harness connector Terminal Test box Socket
1 (B+) 98
2 (signal) 86
3 (Ground -GND-) 108

- Specified value: Wire resistance max 1.5 Ohm

- Also check wires for short circuit to each other as well as to B+ and Ground (GND).
- Specified value: Infinite Ohm (no continuity)

- If necessary, repair wire connection.

Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1 - Check DTC memory "Mode 3: Check DTC memory". Diagnostic Mode 3: Check DTC Memory
2 - If necessary, erase DTC memory "Mode 4: Reset/erase diagnostic data". Diagnostic Mode 4: Reset/Erase Diagnostic Data
3 - Generate readiness code. Readiness Code, Generating
- End diagnosis and switch ignition off.