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 -.