With Manufacturer's Scan Tool
Engine Coolant Temperature (ECT) Sensor -G62-, Checking
Special tools and equipment
- VAG 1526 A
- VAG 1594 A
- VAG 1598/31
- VAS 5051 with VAS 5051/1
Test requirements:
- Engine cold.
Test sequence
- Connect testing and information system VAS 5051 and select vehicle system "01 - Engine electronics" in selection. Engine must be running at idling speed. Connecting VAS 5051 Scan Tool
Display on VAS 5051:
- Under -1- select diagnostic function "08 - Read measured value block".
Display on VAS 5051:
1 - Enter display group - Enter "004" for "display group number 004" in zone -2- and confirm entry by pressing -Q- button.
Display on VAS 5051:
- Check indication in display field -3-.
Display Group 004:
If display zone 3 shows an implausible value:
- Disconnect connector -2- at Engine Coolant Temperature (ECT) sensor -G2-/-G62-.
- Connect multimeter between terminals C and D of sensor to measure resistance.
- Range A shows resistance values for temperature range 0 to 50 degree C and range B shows the values for temperature range 50 to 100 degree C.
Sample readings:
- 30 degree C corresponds to a resistance of 1500 to 2000 Ohms.
- 80 degree C corresponds to a resistance of 275 to 375 Ohms
If specified value is not attained:
- Replace engine coolant temperature sensor.
If specified value is attained:
- Connect test box VAG1598/31 to wiring harness for engine control module; do not connect engine control module. Wiring and Component Testing Using VAG1598/31 Test Box
- Check for open circuit and short to positive or ground in following wiring connections:
Connector Test box VAG 1598/31
terminal Some
3 108
4 (signal) 93
- Test for short circuits between two wires.
- Repair any open/short circuit as necessary.
If no wiring malfunction is detected:
- Replace engine control module.