Charge Air Pressure Sensor, Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram.

Test requirements 

• The Motronic Engine Control Module (ECM) - J220- fuses OK.
  Fig 1: Fuses On E-Box In Engine Compartment, Left Side

  Courtesy of AUDI OF AMERICA, LLC
• 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.

Test procedure 

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK 

Start diagnosis 

-- Remove the engine cover with air filter. Refer to Repair information.

Test sequence 

-- Disconnect the Charge Air Pressure Sensor -G31- electrical harness connector -arrow-.

-- Start engine and let it run at idle.

-- 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 Repair information.

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

-- Remove the Motronic Engine Control Module (ECM) -J220-. Refer to Repair information.

-- 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 T94 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 T94 terminals or test box sockets
1	53
3	19
4	381

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-. Refer to Repair information.

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 Repair information.

-- Install the engine cover with air filter Refer to Repair information.

Final procedures 

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

1. Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .