Intake Air Temperature Sensor 2 (G42) Test Sequence

-- Connect diagnostic tester.

-- Switch ignition on.

-- Under address word 33, select "Diagnostic mode 1: Check measured values."

-- Select the measuring value "PID 15: Intake air temperature".

-- Check specified value of intake air temperature:

PID

Diagnostic text

Specified value:

15:

Intake Air Temperature (IAT)

approx. ambient temperature⁽¹⁾

⁽¹⁾	If a temperature is indicated which is below the ambient temperature of sensor, first check sensor wires for contact resistance. Note that while the vehicle is standing still the sensor might warm up due to radiant heat.

If a substitute value of approx. 134° C is displayed:

-- Check resistance at Intake Air Temperature (IAT) Sensor -G42-, SENSOR, CHECKING RESISTANCE .

If specified value is not obtained:

-- Check Intake Air Temperature (IAT) Sensor -G42-.

Sensor, Checking

-- Remove Intake Air Temperature (IAT) Sensor -G42- with Charge Air Pressure Sensor -G31- (-A-).

Fig 1: Identifying Connector For Intake Air Temperature (IAT) Sensor G42 And Mass Air Flow (MAF) Sensor G70

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Reconnect harness connector to sensor.

-- Remember the intake air temperature value.

-- Spray the sensor with commercially available chilling spray while observing the temperature value. The temperature must decrease.

-- End diagnosis and switch ignition off.

If the intake air temperature does not drop:

-- Replace Intake Air Temperature (IAT) Sensor -G42- with Charge Air Pressure Sensor -G31- INTAKE AIR TEMPERATURE SENSOR, CHECKING .

-- Erase DTC memory of Engine Control Module (ECM) DIAGNOSTIC MODE 04 - ERASE DTC MEMORY

-- Generate readiness code READINESS CODE .