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" 01. Connecting VAS 5051/VAG1551 Scan Tool
Ignition must remain switched on for this.

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.

Indicated on display:


Read measuring value block
Enter 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 value block 4 ->
1 2 3 4


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

NOTE: With cold engine, Intake Air Temperature (in display field 4) must approximately match the coolant temperature (in display field 3).

Display Group 004:

Checking wire connections
- Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM. Wiring and Component Testing Using VAG1598/31 Test Box






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

Harness connector VAG1598/31 test box
Terminal Socket
1 85
2 108

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

If no malfunctions are found in wires:

Checking sensor






- Connect multimeter at sensor for resistance measurement.

Specified values

Temperature (degree C) Resistance (k ohms)
-20 approx.13.8
0 approx.5.5
20 approx. 2.4
40 approx. 1.1
60 approx. 0.6

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

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