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Home >> Audi >> 2000 >> A6 Quattro Sedan (4B4) V8-4.2L (ART) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Air Temperature Sensor ( Ambient / Intake ) >> Testing and Inspection
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Air Temperature Sensor ( Ambient / Intake ): Testing and Inspection




Intake Air Temperature (IAT) sensor -G42, checking

Location of sensor (mass air flow sensor and intake air temperature sensor are combined as one component in air filter housing).

- Connect Vehicle Diagnostic, Testing and Information System VAS5051 or VAG 1551 Scan Tool and select engine electronics control module by entering address word "01". When doing this the ignition must be switched on.

Indicated on display
Rapid data transfer HELP
Select Function XX


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

Indicated on display


Read Measuring Value Block HELP
Input Display Group Number XXX


- Press buttons -0-, -0- and -4- to select Display Group 4 and confirm entry with -Q- button.

Indicated on display: (1 to 4 = display fields)


Read Measuring Value Block 4 ->
1 2 3 4


- Check display value for intake air temperature sensor (display field 4):







Checking wiring
- Switch ignition off.
- Connect VAG 1598/31 test box to wiring harness for engine control module. DO NOT connect to the engine control module itself, Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/Connecting VAG 1598/31 Test Box" Testing and Inspection

- Disconnect harness connector from mass air flow sensor.







- Check for short circuit between wires:

5-pin connector on VAG 1598/31 test
wiring harness, socket box socket
1 27

Specification: infinity ohms (no connection)







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

5-pin connector on VAG 1598/31
wiring harness, socket test box socket
1 85
3 27

Resistance in wiring: max. 1.5 ohms

- Correct any open/short circuit as necessary.

If no wiring malfunction is detected:
- Replace Intake Air Temperature (IAT) sensor -G42. (Mass Air Flow (MAF) sensor and Intake Air Temperature (IAT) sensor are combined as one component in air filter housing).
- Display readiness code. Readiness code must be generated if DTC memory was erased.
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