Charge Air Pressure Sensor, Checking: Notes

Observe all safety precautions: SAFETY PRECAUTIONS 

View clean working conditions: CLEAN WORKING CONDITIONS 

Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.

For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.

Special tools and workshop equipment required 

• Multimeter
• Wiring diagram

Test requirements 

• The Motronic Engine Control Module (ECM) - J623- fuses OK.
  Fig 1: Identifying 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 appropriate service 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: near 5.0 V

-- Switch the ignition off.

-- Continue test according to the following table:

Value	Cause	Test
If the specified value was not obtained:	Open or shorted circuit	CHECKING WIRING
If the specified value was obtained:	Check reference signal circuit	CHECKING WIRING