Camshaft Position (CMP) Sensor G40 , checking

Special tools, testers and auxiliary items required 

• Multimeter.
• Wiring diagram.

Test requirements 

• The Motronic Engine Control Module (ECM) J220 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 → Motronic Engine Control Module (ECM) J220 , replacing 

Start diagnosis 

• Remove the engine cover with air filter.

Fig 1: Identifying Camshaft Position Sensor G40 Electrical Harness Connector

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Disconnect the Camshaft Position (CMP) Sensor G40 electrical harness connector - arrow  -.
• Switch the ignition on.

Fig 2: Checking Camshaft Position Sensor G40 Electrical Harness Connector Terminals 1 To 3 For Voltage

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Using a Multimeter , Check the Camshaft Position (CMP) Sensor G40 electrical harness connector terminals 1 to 3 for voltage.

Specified value: about 4.5 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 Adapter F/VAG1598 (68 Pin) VAG1598/22. 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) J220. Refer to → Motronic Engine Control Module (ECM) J220 , replacing  .

Fig 3: 3-Pin Electrical Harness Connector & Terminals

Courtesy of VOLKSWAGEN UNITED STATES, INC.

• Using a Multimeter , Check the Camshaft Position (CMP) Sensor G40 electrical harness connector to the Motronic Engine Control Module (ECM) electrical harness connector T80 for an open circuit.

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, loose 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 Camshaft Position (CMP) Sensor G40. Refer to 28 - Ignition/Glow plug System  .
• Install the engine cover with air filter.
• Erase the DTC memory. Refer to → Diagnostic Mode 04: Reset/delete diagnostic data 
• Perform a road test to verify repair.

If the DTC does not return:

Repair complete, Generate readiness code. Refer to → Readiness Code  .

• End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:

• Replace the Motronic Engine Control Module (ECM) J220. Refer to → Motronic Engine Control Module (ECM) J220 , replacing  .
• Assembly is performed in the reverse of the removal.

Final procedures 

After the 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.
3. If the DTC memory was erased, generate readiness code.

End of diagnosis