Engine Coolant Temperature Sensor on Radiator, Checking

Diagnostic Procedures




Engine Coolant Temperature Sensor on Radiator, Checking

Special tools, testers and auxiliary items required

• Hand multimeter (V.A.G 1526) or Multimeter (V.A.G 1715)

• Test adapter kit (V.A.G 1594)

• Wiring diagram

Test conditions

• The Ground (GND) connections between engine and body must be OK.

• Ignition switched off.

• Fuses in right instrument panel fuse holder must be OK:

Right instrument panel fuse holder





Test Sequence

- Remove 2-pin connector from Engine Coolant Temperature (ECT) Sensor (on Radiator) (G83).

Check resistance

- Measure resistance at Engine Coolant Temperature (ECT) Sensor (on Radiator) (G83).





Range A displays resistance values for the temperature range of 0 to 50 °C, range B displays resistance values for the temperature range of 50 to 100 °C.





Example:

• 30°C is in range A and corresponds to a resistance of 1.5 to 2.0 kohms

• 80°C is in range B and corresponds to a resistance of 275 to 375ohms

If specification is not obtained:

- Replace Engine Coolant Temperature (ECT) Sensor (on Radiator) (G83).

CAUTION!
• Cooling system is under pressure.

• Danger of scalding when opening!

- Erase DTC memory of Engine Control Module (=> [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.

If specification is obtained:

- Check wires to control module according to wiring diagram.

Check wires to control module

- Connect test box to Engine Control Module (ECM) (J623) wiring harness on connecting test box for wiring test, refer to Repair Manual,

- Check wires between test box and 2-pin connector to Engine Control Module for open circuit according to wiring diagram. Terminal 1+Socket 17, Terminal 2+Socket 50, wire resistance: max. 1.5 ohms





- Check wires for short circuit to each other, to vehicle Ground (GND) and to B+. Specification: infinite ohms

- Erase DTC memory of Engine Control Module => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.

If no malfunctions are detected in the wires and the resistance values are OK:

If no malfunction is detected in the wiring, replace the engine control module.