Engine Coolant Temperature (ECT) Sensor - G62 -, Checking
Engine Coolant Temperature (ECT) Sensor -G62-, Checking
Special Tools and Equipment
- VAG1526A
- VAG1594A
- VAG1598/31
- VAS5051 with VAG5051/1
Test requirement:
- Engine cold
Test sequence
- Connect VAS5051 tester and select vehicle system "01 - Engine electronics". Engine must run at idle for this. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/VAS 5051 Tester, Connecting and Selecting Functions" Testing and Inspection
Display on VAS5051:
- Select diagnostic function "08 - Read Measuring Value Block" in selection -1-.
Display on VAS5051:
1 - Enter display group Max. input value = 255
- Select function "004" in button field -2- for "display group number 004" and press Q button to confirm input.
Display on VAS5051:
- Check coolant temperature sensor in display field -3-.
Display Group 004:
- Press "08 - Read Measuring Value Block" to end function <- button.
If display field 3 does not have a realistic indication:
- Disconnect connector at coolant temperature sensor.
- Connect multimeter between terminal C and D of sensor for resistance measurement.
Range A shows the resistance values for the temperature range from 0-50 °C, and range B shows the values for the temperature range from 50-100 °C.
Read-out examples:
- 30 °C corresponds to a resistance of 1500 to 2000 ohms W
- 80 °C corresponds to a resistance of 275 to 375 ohms
If specified value is not obtained:
- Replace coolant temperature sensor.
If specified value is obtained:
- Connect VAG1598/31 test box at wiring harness to Engine Control Module (ECM), do not connect ECM. Refer to "Scan Tool Testing/Wire and Component Testing Using VAG1598/31 Test Box" Testing and Inspection
- Check the following wire connections for open circuit and short circuit to Ground (GND) and B+:
- Check both wires to each other for short circuit.
- Repair open circuit or short circuit if necessary.
If no malfunctions are found in wires:
- Replace Engine Control Module (ECM).