Camshaft Position (CMP) Sensor G40 and Camshaft Position (CMP) Sensor 3 G300 , checking: Notes

The following procedure is used to diagnose Camshaft Position (CMP) Sensor G40 and Camshaft Position (CMP) Sensor 3 G300 which are controlled by Motronic Engine Control Module (ECM) J623.

Special tools, testers and auxiliary items required 

• Multimeter.
• Wiring diagram.

Test requirements 

• The Motronic Engine Control Module (ECM) J623 fuses OK.
• Battery voltage at least 12.5 volts.
• 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 .

Start diagnosis 

• Disconnect the Camshaft Position (CMP) Sensor G40 electrical harness connector - 3  -.

Or 

• Disconnect the Camshaft Position (CMP) Sensor 3 G300 electrical harness connector - 1  -.
• Switch the ignition on.

• Using a Multimeter , Check the Camshaft Position (CMP) Sensor electrical harness connector terminals 1 to 3 for voltage.

Specified value: about 5.0 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. Refer to → 24 - MULTIPORT FUEL INJECTION (MFI) .

If the manufacturers test box is not being used. Perform the following step.

• Remove the Motronic Engine Control Module (ECM) J623. Refer to → Engine Control Module (ECM) J623 , removing and installing .

• Using a Multimeter , Check the Camshaft Position (CMP) Sensor electrical harness connector to the Motronic Engine Control Module (ECM) J623 electrical harness connector T60 for an open circuit.

Camshaft Position (CMP) Sensor G40 electrical harness connector terminals	Motronic Engine Control Module (ECM) J623 electrical harness connector T60 terminals or test box sockets
1	26
2	44
3	52

Camshaft Position (CMP) Sensor G300 electrical harness connector terminals	Motronic Engine Control Module (ECM) J623 electrical harness connector T60 terminals or test box sockets
1	26
2	59
3	52

Specified value: 1.5 Ω Max.

If the specified value was not obtained:

• Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).
• Check the wiring connection for damage, corrosion, lose or broken terminals.
• If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and voltage supply was OK:

• Replace the faulty Camshaft Position (CMP) Sensor G40 or Camshaft Position (CMP) Sensor 3 G300. Refer to → 15 - ENGINE - CYLINDER HEAD, VALVETRAIN .

If no malfunction is found in the wiring and voltage supply was not OK:

• Replace the Motronic Engine Control Module (ECM) J623. Refer to → Engine Control Module (ECM) J623 , removing and installing .

Final procedures 

After repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory.
2. If necessary, erase the DTC memory. Refer to Diagnostic Mode 04: Reset/delete diagnostic data .
3. If the DTC memory was erased, generate readiness code. Refer to Readiness Code Description .

• End of diagnosis.