DTC 42: Fuel Temperature Sensor
- Check Input Signal
Start engine and warm to operating temperature. Measure voltage between ECM terminal No. 36 and ground. See Figure and Fig 2 . Voltage should be less than 5 volts. If voltage is okay, go to next step. If voltage is not okay, go to step 4). - Check Circuit Continuity
Turn ignition off. Disconnect ECM and fuel temperature sensor wiring harness connector. See Figure and Fig 1 . Check continuity between ECM connector terminal No. 36 (Brown wire) and fuel temperature sensor connector terminal (Brown wire). If continuity is present, go to next step. If continuity is not present, repair harness or connectors as necessary. - Check Component
Check fuel temperature sensor resistance. See FUEL TEMPERATURE SENSOR RESISTANCE SPECIFICATION table. Replace fuel temperature sensor if necessary, and perform FINAL CHECK in this article. If fuel temperature sensor is okay, repair ECM pin terminals and/or wiring harness connector. - Clear Memory
Erase ECM memory and repeat Mode II of self-diagnostics. If DTC 42 does not repeat, testing is complete. If DTC 42 is repeated, repair ECM pin terminals and/or wiring harness connector, and perform FINAL CHECK in this article.
FUEL TEMPERATURE SENSOR RESISTANCE SPECIFICATION
| Temperature °F (°C) | Ohms |
|---|---|
| 68 (20) | 2100-2900 |
| 122 (50) | 680-1000 |
| 176 (80) | 300-330 |