Manifold Absolute Pressure Sensor / Intake Air Temperature Sensor, Checking: Notes

The following procedure is used to diagnose the Manifold Absolute Pressure (MAP) Sensor -G71- and Intake Air Temperature (IAT) Sensor -G42- which is controlled by Engine Control Module -J623-.

NOTE:

The Intake Air Temperature (IAT) Sensor -G42- is part of the Manifold Absolute Pressure (MAP) Sensor -G71- and cannot be replaced separately.

Use only gold-plated terminals when servicing terminals in harness connector of Manifold Absolute Pressure (MAP) Sensor -G71- /Intake Air Temperature (IAT) Sensor -G42-.

Special tools and workshop equipment required

multimeter.
Wiring diagram.

Test requirements

The Engine Control Module -J623- fuse OK.
Battery voltage at least 12.5 volts.
All electrical consumers such as, lights and rear window defroster, switched OFF.
Vehicles with automatic transmission, shift selector lever into position "P" or "N".
A/C switched OFF.
Ground (GND) connections between engine/transmission/chassis OK.
Coolant Temperature at least 80° C.
Ignition switched OFF.

Test procedure

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .

Start diagnosis

-- Connect the scan tool.

-- Using the scan tool, Check the temperature of the Intake Air Temperature (IAT) Sensor -G42- at idle:

-- Remove the engine covers. Refer to the appropriate Service Information.

Fig 1: Engine Cover -1- And -2-

Courtesy of AUDI OF AMERICA, LLC

-- Start engine and let idle.

Diagnostic text		Specified value
Engine running at idle		Approx. ambient temperature

-- Switch the ignition OFF.

If the specified value was obtained:

-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

-- If necessary, repair the faulty wiring connection.

-- Go to Final procedures.

If any of the specified value was Not obtained:

-- Disconnect the Manifold Absolute Pressure (MAP) Sensor -G71- Intake Air Temperature (IAT) Sensor -G42- electrical harness connector -1-.

Fig 2: Identifying Connector -1- & Intake Air Temperature Sensor/Manifold Absolute Pressure Sensor Bolts

Courtesy of AUDI OF AMERICA, LLC

-- Switch the ignition ON.

-- Using a Multimeter, check the Manifold Absolute Pressure (MAP) Sensor -G71- Intake Air Temperature (IAT) Sensor -G42- electrical harness connector terminals 1 to 3 for voltage.

Specified value: near 5.0 V.

-- Switch the ignition OFF.

-- Continue test according to the following table:

Value	Cause	Test
If the specified value was not obtained:	Open or shorted circuit	MANIFOLD ABSOLUTE PRESSURE SENSOR / INTAKE AIR TEMPERATURE SENSOR, CHECKING => Checking wiring
If the specified value was obtained:	Check reference signal / Component	MANIFOLD ABSOLUTE PRESSURE SENSOR / INTAKE AIR TEMPERATURE SENSOR, CHECKING => Component Check