Testing if display approx. 140°C:

-- Disconnect the IAT sensor - G42- electrical harness connector.

-- Turn the ignition switch ON

-- Check the value indicated on the scan tool display.

-- Switch ignition OFF.

If indication jumps to approx. - 40°C or - 46°C:

-- Replace the IAT sensor - G42-. Refer to the Repair Information.

If the indication remains at approx. 140° C

-- Remove the Engine Control Module (ECM) -J623-. Refer to the Repair Information.

-- Disconnect the ECM harness.

-- Using a multimeter, check the IAT sensor - G42- electrical harness connector terminal 1 to engine ground.

Fig 1: 2-Pin Electrical Connector & Terminals

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Specified value: OL or no continuity.

If the specified value was Not obtained:

-- Check the wiring for a short circuit to Ground.

-- If necessary, repair the faulty wiring connection.

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

If no malfunction is detected in the wiring and the sensor resistance was OK:

-- Replace the Engine Control Module (ECM) -J623-. Refer to the Repair Information.