Testing if display is approx. - 40.0° C:

-- Disconnect the Engine Coolant Temperature (ECT) Sensor (on radiator) -G83- electrical harness connector -1-.

Fig 1: Identifying Engine Coolant Temperature (ECT) Sensor (On Radiator) Electrical Harness Connector

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Using a jumper wire, connect the Engine Coolant Temperature (ECT) Sensor (on radiator) -G83- electrical harness connector terminals 1 to 2.

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

Fig 2: 2-Pin Electrical Connector & Terminals

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

If the value jumps to approx. 140.0° C

-- Switch the ignition off.

-- Replace the Engine Coolant Temperature (ECT) Sensor (on radiator) - G83-. Refer to the Repair information.

If indication remains at approx. -40.0° C: