Camshaft Position Sensors, Checking
This procedure is used to check Camshaft Position (CMP) Sensors -G40, G300, G163, G301-.
Use only gold-plated terminals when servicing terminals in the electrical harness connectors of the Camshaft Position (CMP) Sensor -G40-.
Special tools and workshop equipment 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 customer's 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.
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 Component Locations Overview .
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 Component Locations Overview .
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)J623Wiring 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)J623Wiring 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)J623Wiring 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)J623Wiring 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. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .