Manufacturer's Scan Tool
Engine Coolant Temperature Sensor, Checking
Special tools, testers and auxiliary items required
• Multimeter (V.A.G 1526 A)
• Connector test kit (V.A.G 1594 A)
• Test box (VAG1598/31)
• Vehicle diagnostic, testing and vehicle information system (VAS 5051) with Adapter (VAS 5051/1 )
Component location => [ (Item 5) ] Locations, => [ (Item 3) 55 Nm ] Locations
Requirements
• Engine cold
Work sequence
- Connect vehicle diagnostic, testing and information system (VAS 5051) => [ VAS5051, Connecting and Selecting Functions ] VAS 5051, Connecting and Selecting Functions and select vehicle system "01 -Engine electronics" in selection. Engine must be run at idle.
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 Engine Coolant Temperature (ECT) sensor ( G62) in display zone - 3 -.
If display zone 3 shows an implausible value:
- Disconnect connector at Engine Coolant Temperature (ECT) sensor (G2) / (G62) (arrow).
- Connect multimeter between terminals C and D of sensor to measure resistance.
Range A shows resistance values for temperature range 0...50 °C and range B shows the values for temperature range 50...100 °C.
Sample readings:
• 30° C corresponds to a resistance of 1500 to 2000 ohms
• 80° C corresponds to a resistance of 275 to 375 ohms
If specified value is not obtained:
- Replace Engine Coolant Temperature (ECT) sensor ( G62).
If specified value is obtained:
- Connect test box (VAG1598/31) to wiring harness for ECM; do not connect directly to ECM => [ Electrical Testing, with Test Box VAG 1598/31 ] Electrical Testing, With Test Box VAG 1598/31.
- Check for open circuit, short to positive, or short to ground in following wiring connections:
- Test for short circuits between two wires.
- Repair any open/short circuit as necessary.
If no wiring problems are found:
- Replace ECM => [ Engine Control Module without Metal Anti-Theft Housing, Replacing ] Engine Control Module Without Metal Anti-Theft Housing, Replacing.