Air Temperature Sensor ( Ambient / Intake ): Testing and Inspection

Intake Air Temperature (IAT) Sensor, checking

^ VAG 1551 Scan Tool (ST) connected Connecting VAG 1551 Scan Tool


- Start engine and let idle.
- Operate VAG 1551 Scan Tool (ST) according to information indicated on display:
^ Rapid data transfer operating mode
^ Address word 01 for "Engine Electronics"

- Indicated on display

[Rapid data transfer HELP ]
[Select function XX ]

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

- Indicated on display

[Read measuring value block HELP ]
[Enter display group number XX ]

- Press button -0- twice to enter display group number 00, and press -Q- button to confirm input.

- Indicated on display
(1-10 = display fields)

[Read measuring value block => ]
[1 2 3 4 5 6 7 8 0 10 ]

Note:
^ If something different is indicated on the display refer to VAG 1551 Scan Tool (ST) operating instructions.
^ If "Error in data transfer" is displayed (caused by an input error) disconnect the cable from VAG 1551, reconnect, and begin the test sequence again.

- Remove Intake Air duct,
- Spray Intake Air Temperature Sensor (G42) with chilling spray (commercially available) and observe value displayed in display field 4.
^ Displayed value must increase

- Press buttons -0- and -6- to select "End Output" function.
- Press -Q- button to confirm input.

If the display/temperature value does not change as specified:
- Carry out electrical testing, test step 14. Pinout Values and Diagnostic Parameters
- If necessary, replace housing for Fuel Injector with Intake Air Temperature Sensor (G42).