Engine Coolant Temperature (ECT) Sensor -G62-, Checking
Engine Coolant Temperature (ECT) Sensor -G62-, Checking
Special tools and equipment
- VAG1526A or Fluke 83 Multimeter
- VAG1594A Connector test kit
- VAG1598/31 Test box
- VAS5051 Vehicle diagnosis, testing and information system with VAS5051/1 Adapter
Requirement
- Engine cold
Work sequence
- Connect VAS5051 tester, Vehicle Diagnostic, Testing and Information System VAS 5051, Connecting and Selecting Functions and select vehicle system "01 - Engine electronics". Engine must run at idle.
Display on VAS5051:
- Select diagnostic function "08 - read measured 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.
- Press <- button to end function "08 - Read measuring value block".
If display field 3 does not have a realistic indication:
- Disconnect connector at coolant temperature sensor.
- Connect multimeter between terminals -C- and -D- of sensor for resistance measurement.
Range A displays resistance values for the temperature range of 0...50 degrees C, range B displays resistance values for the temperature range of 50... 100 degrees C.
Read examples:
- 30 degrees C corresponds to a resistance of 1500 to 2000 Ohms
- 80 degrees C corresponds to a resistance of 275 to 375 Ohms
If specified value is not obtained:
- Replace ECT sensor.
If specified value is obtained:
- Connect VAG1598/31 test box at wiring harness to Engine Control Module (ECM) but do not connect ECM.
- Check following wiring connections for open circuit and short circuit to Ground (GND) and B+:
Harness connector Terminal VAG1598/31 test box Socket
3 (signal) 93
4 108
- Check both wires to each other for short circuit.
- Repair open circuit in wiring or short circuit if necessary.
If no malfunctions are found in wires:
- Replace Engine Control Module (ECM).