Checking Wiring

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

-- Using a multimeter, check the Engine Coolant Temperature (ECT) Sensor -G62 or 83- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T60 terminals for an open circuit or a short to voltage, refer to the chart below.

Engine Coolant Temperature (ECT) Sensor - G62- electrical harness connector terminals:	Engine Control Module (ECM) -J623- electrical connector T60 terminals:
1	57
2	14

Engine Coolant Temperature (ECT) Sensor - G83- electrical harness connector terminals:	Engine Control Module (ECM) -J623- electrical connector T94 terminals :
1	36
2	12

Specified values: 1.5 Ω Max. and 0 volts with key on and ECM disconnected.

If the specified value was Not obtained:

-- Check the wiring for an open or short circuit to Battery (+).

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

-- If necessary, repair the faulty wiring connection.

If the specified value was obtained:

-- Using a multimeter, check terminal 2 of the ECT sensor to engine ground.

Specified value: 1.5 Ω Max

If the specified value was Not obtained:

-- Check the wiring for an open circuit or high resistance.

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

-- If necessary, repair the faulty wiring connection.

If the specified value was obtained:

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

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

-- Disconnect the ECT harness connector at the sensor.

-- Using a multimeter, check the signal circuit of the Engine Coolant Temperature (ECT) Sensor -G62 or 83- electrical harness connector terminal 1 to engine ground.

Specified value: OL or no continuity.

If the specified value was Not obtained:

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

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

-- If necessary, repair the faulty wiring connection.

If the specified value was obtained:

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

-- 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 the Engine Control Module (ECM) -J623- electrical harness connector T60 terminal 42 for an open circuit or a short to voltage, refer to the appropriate System Wiring Diagram Information.

Fig 1: Identifying 2-Pin Electrical Connector & Terminals

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

Specified values: Circuit continuity; 1.5 Ω max; Circuit voltage = 0 volts when disconnected from ECM (with ignition on).

If the specified value was Not obtained:

-- Check the wiring for an open, high resistance or short circuit to Battery (+)

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

-- If necessary, repair the faulty wiring connection.

If the specified value was obtained:

-- Using a multimeter, check terminal 2 of the IAT sensor to engine ground.

Specified value: 1.5 Ω Max

If the specified value was Not obtained:

-- Check the wiring between terminal 2 of the IAT and T60/14 of the ECM connector for an open circuit or high resistance.

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

-- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the ground circuit:

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