Checking signal wire

• Disconnect harness connector at charge air pressure sensor.
• Connect multimeter to socket 101 and socket 108 of test box for voltage measurement.
• Start engine and let it run at idle.
  • Specified value: about 1.90 V
• Bring engine to RPM by depressing pedal suddenly.
  • Specified value: approx. 2.00 ... 3.00 V

If specified values are not obtained:

• Check the following wire connection for open circuit and short circuit to Ground (GND) and B+:
  Fig 1: Identifying Charge Air Pressure Sensor Harness Connector Terminals

  Courtesy of AUDI OF AMERICA, INC.
  CHARGE AIR PRESSURE SENSOR CIRCUIT TEST: SIGNAL WIRE
  
  

  Harness connector Terminal	VAG1598/31 test box Socket
  4	101

• Repair open circuit or short circuit if necessary.

If wire connection is OK:

• Replace the Charge Air Pressure Sensor -G31-.