Charge Air Pressure Sensor G31 , checking

WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Use only gold-plated terminals when servicing terminals in harness connector of Charge Air Pressure Sensor G31.

Special tools, testers and auxiliary items required

Multimeter.
Wiring diagram.

Test requirements

Fig 1: Identifying Main Fuse Panel

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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.
On vehicles with automatic transmission, selector lever in position "P" or "N".

A/C switched off.
Ground (GND) connections between engine/transmission/chassis OK.
Ignition switched off.

Procedure

Fig 2: Removing Engine Cover

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Remove the engine cover with air filter → 24 MULTIPORT FUEL INJECTION (MFI) .

Test sequence

Fig 3: Disconnecting Connector On Charge Air Pressure Sensor Electrical Harness Connector

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Disconnect the Charge Air Pressure Sensor G31 electrical harness connector - arrow -.
Start engine and let it run at idle.

Fig 4: Identifying 4-Pin Electrical Harness Connector & Terminals

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Using a multimeter , check the Charge Air Pressure Sensor G31 electrical harness connector terminals 1 to 3 for voltage.

Specified value: min. 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 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) J220. Refer to → Motronic Engine Control Module (ECM) J220 , replacing .

Fig 5: Identifying 4-Pin Electrical Harness Connector & Terminals

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Using a multimeter , check the Charge Air Pressure Sensor G31 electrical harness connector terminals to the Motronic Engine Control Module (ECM) J220 electrical harness connector terminals for an open circuit according to wiring diagram.

Charge Air Pressure Sensor G31 electrical harness connector terminals	Motronic Engine Control Module (ECM) J220 electrical connector test box sockets
1	108
3	98
4	101

Specified value: 1.5 Ω max.

If the specification was not obtained:

Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).
If necessary, repair the faulty wiring connection.
Check the electrical harness connector for damage, corrosion, lose or broken terminals.

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

Replace the Charge Air Pressure Sensor G31 → 24 MULTIPORT FUEL INJECTION (MFI) .

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

Replace the Motronic Engine Control Module (ECM) J220. Refer to → Motronic Engine Control Module (ECM) J220 , replacing .
Install the engine cover with air filter → 24 MULTIPORT FUEL INJECTION (MFI) .

Final procedures

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 .

End of diagnosis.