Checking wiring

Disconnect connector to Intake Air Temperature (IAT) sensor -G42-.
Connect test box V.A.G 1598/31 to wiring harness for ECM; do not connect ECM. See ELECTRICAL TESTING USING VAG1598/31 TEST BOX .
Check for open circuit, short to positive, or short to ground in following wiring connections:

Fig 1: Identifying Intake Air Temperature Sensor Harness Connector Terminals

Courtesy of AUDI OF AMERICA, INC.

IAT SENSOR CIRCUIT CHECK: TERMINAL 1, 2 & SOCKET 85, 108

Connector terminal	Test box V.A.G 1598/31 Socket
1	85
2	108