Intake Air Temperature (IAT) Sensor -G42- Checking

Intake Air Temperature (IAT) Sensor -G42- Checking

Special Tools and Equipment







- VAG1526A
- VAG1594A
- VAG1598/31
- VAS5051 with VAG5051/1
or
- VAG1551 with VAG1551/3B

Test sequence
- Connect VAS5051 tester or VAG1551 scan tool and select the control module for engine electronics using "address word". [1][2]Scan Tool Connecting and Initial Checks
Ignition must remain switched on for this.

When indicated on display:


Rapid data transfer HELP
Select function XX


- Press buttons -0- and -8- to select "Read Measuring Value Block" and press -Q- button to confirm input.

When indicated on display:


Read Measuring value Q
Input display group number XXX


- Press buttons -0-, -0- and -4- to select "display group number 004" and press -Q- button to confirm input.

Indicated on display:


Read Measuring Valve Block 4 ->
1 2 3 4


- Check specified value for Intake Air Temperature (IAT) sensor in display field 4:

Display Group 004:

Checking wire connections
- Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM. Connecting VAG 1598/31 Test Box







- Check the following wire connections for open circuit and short circuit to Ground (GND) and B+:







- Check both wires to each other for short circuit.
- Repair open circuit or short circuit if necessary.

If no malfunctions are found in wire:

Check sensor:
- Disconnect connector from Intake Air Temperature (IAT) sensor.







- Connect multimeter at sensor for resistance measurement.

Specified values







Example:
If air temperature is in a range from 0 °C to 20 °C, the resistance value must be between 5 kOhms and 2.4 kOhms


If specified value is not obtained:
- Replace Intake Air Temperature (IAT) sensor.