Engine Coolant Temperature Sensor
- Ensure engine is cold. Connect Scan Tester (VAG 1551) to Data Link Connectors (DLC) located in center console. Start engine and allow it to idle. With scan tester in READ MEASUREMENT BLOCK function, read coolant temperature value in channel No. 1 of scan tester.
- If temperature value increases uniformly without interruption, sensor and its circuit are okay. Select END OUTPUT function on scan tester. If display value is incorrect, check for an open engine coolant temperature circuit or for a short circuit to ground.
- If necessary, use test leads from Adapter Kit (VAG 1594) to measure ECT sensor resistance. See Fig 1 . See COOLANT TEMPERATURE SENSOR RESISTANCE table below.
COOLANT TEMPERATURE SENSOR RESISTANCE
| Temperature °F (°C) | Ohms |
|---|---|
| 68 (20) | 3000-2000 |
| 86 (30) | 2000-1500 |
| 104 (40) | 1500-1000 |
| 122 (50) | 1000-800 |
| 140 (60) | 700-500 |
| 158 (70) | 500-375 |
| 176 (80) | 375-275 |
| 194 (90) | 275-225 |