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Engine Coolant Temperature (ECT) Sensor (on Radiator), Checking



Engine Coolant Temperature (ECT) Sensor (On Radiator), Checking

Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 connector test kit
- Wiring diagram

Test requirements







- Fuses in E-box (in plenum chamber, left) must be OK:
- Ground (GND) connections between engine and chassis must be OK.
- Ignition switched off.

Test sequence







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

Checking 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 degrees C, range B displays resistance values for the temperature range of 50 to 100 degrees C.

Read-out examples:
- 30 degrees C is in range A and corresponds to a resistance of 1.5 to 2.0 k ohms.
- 80 degrees C is in range B and corresponds to a resistance of 275 to 375 ohms.

If specified value is not obtained:
- Replace Engine Coolant Temperature (ECT) Sensor (on Radiator) -G83-.

WARNING:
- The cooling system is under pressure.
- Danger of scalding when opening.


- Erase DTC memory of Engine Control Module (ECM). Diagnostic Mode 04 - Erase DTC Memory
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If specified value is obtained:
- Check wires according to wiring diagram.

Checking wiring
- Connect test box to control module wiring harness. Connecting Test Box For Wiring Test







- Check wires between test box and 2-pin connector for open circuit according to wiring diagram.
Terminal 1+socket 17
Terminal 2+socket 50

Wire resistance: max. 1.5 ohms.

- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+.

Specified value: infinity ohms.

- Erase DTC memory of Engine Control Module (ECM). Diagnostic Mode 04 - Erase DTC Memory
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If no malfunctions are detected in the wires and the resistance values are OK:
- Replace Motronic Engine Control Module (ECM) - J220 -.