Intake Air Temperature (IAT) Sensor -G42-, Testing

Intake Air Temperature (IAT) Sensor -G42-, Testing







Special tools and equipment
- VAG 1526 A
- VAG1594 A
- VAG 1598/31
- VAG 5051 with VAS 5051/1

Test sequence
- Connect the vehicle diagnostic, testing and information system VAS 5051, Vehicle Diagnostic, Testing and Information System VAS 5051, Connecting and Selecting Functions , and select the vehicle system "01 - Engine electronics" from the menu. When doing this the engine should be idling.







Display on VAS 5051:
- Select the diagnosis function "08 - Read data block" from the menu -1-.







Display on VAS 5051:
1 - Enter display group
(figures up to 255)
- Using the keypad -2-, enter "004" to select Display group 004 and confirm entry with Q button.







Display on VAS 5051:
- Check display value for intake air temperature sender (display zone -4-):







- Press the <- button to exit from the function "08 - Read data block".

Checking wiring connections
- Connect test box VAG 1598/31 to wiring harness for engine control module. Do not connect to the engine control module itself. Scan Tool Testing and Procedures







- Unplug connector -1- at intake air temperature sender -G42 -2-.







- Test for open circuit and short to positive or Ground in the following wiring connections:

Connector Contact Test box VAG 1598/31 Socket
1 85
2 108

- Test for short circuits between the two wires.
- Correct any open/short circuit as necessary.

If no malfunction is detected:
- Test intake air temperature sender.

Testing sender







- Connect multimeter (resistance measurement range) to sender.

Specifications:

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

If the specification is not attained:
- Install a new intake air temperature sender.