Use this procedure in order to troubleshoot high fuel temperature. Use this procedure if one of the following event codes is active. Refer to Troubleshooting, “Diagnostic Trouble Codes” for information about event codes and the default trip points for these codes. You must access the monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these codes.
| Event Code | ||
|---|---|---|
| Code and Description | Conditions which Generate this Code | System Response |
| 174-0 Fuel Temperature Sensor : High | The fuel temperature is above the trip point for the specified delay time. | The code is logged. |
Probable Causes
- Fuel pressure regulating valve
- Fuel level
- Fuel lines
- Overheated engine
- Fuel temperature sensor
Recommended Actions
Fuel Pressure Regulating Valve
An improperly operating fuel pressure regulating valve may cause high fuel temperature. If a problem is suspected, inspect the return fuel pressure regulating valve. Clean any contamination or debris that may keep the regulating valve from operating properly. If debris is present, find the source of the contamination. Replace the return fuel pressure regulating valve if the valve is worn or damaged.
Fuel Level
Ensure that the fuel tank contains enough fuel. As the fuel tank level decreases, the fuel temperature generally increases.
Fuel Lines
Restricted fuel return lines may produce very high fuel temperatures. Ensure that the fuel return flow to the fuel tank is not obstructed.
Overheated Engine
The fuel is supplied to the injectors through a passage in the cylinder head. Abnormally high ambient air temperature could cause the fuel temperature to reach the trip level. An overheated engine could cause the fuel temperature to reach the trip level.
Fuel Temperature Sensor
Verify that the fuel temperature sensor has been installed correctly. If an electrical problem is suspected with the sensor, refer to Troubleshooting, “Sensor Signal (Analog, Active) – Test”.