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
- The respective fuses of Motronic Engine Control Module (ECM) -J220- must be OK:
- Fuses -1, 2, 3, 4 and 7- in protective housing (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:
- Cooling system is under pressure.
- Danger of scalding when opening!
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If specified value is obtained:
Checking wiring
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting 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 4: Reset/erase diagnostic data.
- 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-.