Camshaft Position Sensors, Checking
This procedure is used to check Camshaft Position (CMP) Sensors G40, G300, G163, G301.
NOTE:
- Use only gold-plated terminals when servicing terminals in the electrical harness connectors of the Camshaft Position (CMP) Sensor G40.
Special tools, testers and auxiliary items required
- Multimeter.
- Diode test lamp.
- Wiring diagram.
Test requirements
- The Engine Control Module (ECM) J623 fuses OK.
- Engine Control Module (ECM) Power Supply Relay J363 OK.
- Battery voltage at least 12.5 V.
- All electrical consumers such as, lights and rear window defroster, switched off.
- Vehicles with automatic transmission, shift selector lever into position "P" or "N".
- A/C switched off.
- Ground (GND) connections between engine/transmission/chassis OK.
- Ignition switched off.
Test procedure
- Perform a preliminary check to verify the customers complaint. Refer to → Preliminary Check .
- Remove the front engine cover - arrows -.
- Remove the rear engine cover - arrows -.
Checking activation
- Using the Diode test lamp , check for voltage between terminal 2 (CMP sensor signal) and terminal 1 (B+) with the electrical harness connector connected to the Camshaft Position (CMP) Sensor.
- Operate the starter for a few Sec.
The 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 the LED blinks:
Replace the relevant Camshaft Position (CMP) Sensor. Refer to 24 - FUEL INJECTION SYSTEM .
If the LED does not blink:
Checking voltage supply
- Disconnect the relevant Camshaft Position (CMP) Sensor electrical harness connector.
- Switch the ignition on.
- Using a Multimeter , check the Camshaft Position (CMP) Sensor electrical harness connector terminal 1 to engine ground for voltage.
| Camshaft Position (CMP) Sensor Electrical Harness Connector Terminal | Measure to |
|---|---|
| 1 | Engine Ground (GND) |
Specified value: about 5 V.
- Switch the ignition off.
Checking signal wire
- Using a Multimeter , Check the Camshaft Position (CMP) Sensor electrical harness connector terminal 2 to engine ground for voltage.
| Camshaft Position (CMP) Sensor Electrical Harness Connector Terminal | Measure to |
|---|---|
| 2 | Engine Ground (GND) |
- Switch the ignition on.
Specified value: Battery voltage.
- Switch the ignition off.
Checking Ground (GND)
- Using a Multimeter , Check the Camshaft Position (CMP) Sensor electrical harness connector terminal 3 to engine ground for voltage.
| Camshaft Position (CMP) Sensor Electrical Harness Connector Terminal | Measure to |
|---|---|
| 3 | Battery positive (+) |
Specified value: about 10 V.
- Switch the ignition off.
If the specification was not obtained:
Checking wiring
If the manufacturers test box is being used, perform the following step.
- Install the test box VAG1598/42. Refer to 24 - FUEL INJECTION SYSTEM .
If the manufacturers test box is not being used, perform the following step.
- Remove the Engine Control Module (ECM) J623. Refer to → Engine Control Module, Replacing .
- Using a Multimeter , Check the Camshaft Position (CMP) Sensor electrical harness connector to the Engine Control Module (ECM) J623 electrical harness connector for resistance.
- Camshaft Position (CMP) Sensor G40 (bank 1).
| Camshaft Position (CMP) Sensor Electrical Harness Connector Terminal | Engine Control Module (ECM) J623 Wiring Harness Connector Terminal or Test box Socket |
|---|---|
| 1 Battery positive (+) | 11 |
| 2 (signal) | 25 |
| 3 Ground (GND) | 40 |
- Camshaft Position (CMP) Sensor 2 G163 (bank 2).
| Camshaft Position (CMP) Sensor Electrical Harness Connector Terminal | Engine Control Module (ECM) J623 Wiring Harness Connector Terminal or Test box Socket |
|---|---|
| 1 Battery positive (+) | 11 |
| 2 (signal) | 9 |
| 3 Ground (GND) | 40 |
- Camshaft Position (CMP) Sensor 3 G300 (bank 1).
| Camshaft Position (CMP) Sensor Electrical Harness Connector Terminal | Engine Control Module (ECM) J623 Wiring Harness Connector Terminal or Test box Socket |
|---|---|
| 1 Battery positive (+) | 11 |
| 2 (signal) | 54 |
| 3 Ground (GND) | 40 |
- Camshaft Position (CMP) Sensor 4 G301 (bank 2).
| Camshaft Position (CMP) Sensor Electrical Harness Connector Terminal | Engine Control Module (ECM) J623 Wiring Harness Connector Terminal or Test box Socket |
|---|---|
| 1 Battery positive (+) | 11 |
| 2 (signal) | 24 |
| 3 Ground (GND) | 40 |
If the specification is not obtained:
- Check the wiring for a short circuit to Battery positive (+) or an open circuit.
- If necessary, repair the wiring connection.
If no malfunction can be found:
- Replace the Engine Control Module (ECM) J623. Refer to → Engine Control Module, Replacing
Assembly is performed in the reverse order of removal.
After the repair work, the following work steps must be performed in the following sequence:
- Check the DTC memory.
- If necessary, erase the DTC memory. Refer to Diagnostic Mode 04 - Reset/Delete Diagnostic Data .
- If the DTC memory was erased, generate readiness code. Refer to Readiness Code .