GUARD AS 5336152 - Caterpillar

Illustration 1 g02794262
Location of the high-pressure fuel temperature sensor (view of the high-pressure fuel pump)
Use this procedure in order to troubleshoot high fuel temperature. Also, use this procedure if one of the following event codes is active. Refer to Troubleshooting, "Event Codes" for information about event codes. Access the engine monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these codes. For information on the engine monitoring system, refer to Troubleshooting, "Engine Monitoring System".
Table 1
Event Code
CDL Code and Description Conditions which Generate this Code System Response
E770(1) High Fuel Rail Temperature The fuel temperature of the high-pressure system is above the trip point for the programmed delay time. The code is logged.
E770(2) High Fuel Rail Temperature The code is logged.
Engine power will be derated.
E770(3) High Fuel Rail Temperature The code is logged.
The engine is shut down. If high fuel temperature shuts down the engine, cycle the power to the engine Electronic Control Module (ECM) in order to restart.Probable Causes
Diagnostic codes and event codes
Fuel temperature sensorsRecommended Actions
Diagnostic Codes and Event Codes
Connect Cat (ET) to the service tool connector. Check for active diagnostic codes and event codes.Look for active and logged diagnostic codes and events that are related to the high-pressure fuel system and the low-pressure fuel system. Use the appropriate circuit test to troubleshoot any active diagnostic codes before continuing.Use the time stamps for the logged events in order to determine when the events were active. Take the following actions:If the E363 was active while the E770 was active, the low-pressure fuel system is delivering high temperature fuel to the high-pressure pump. High fuel supply temperatures can elevate the high-pressure fuel temperature enough to trip the E770 code. Troubleshoot the low-pressure fuel system for the active E363. When the problem for the low-pressure fuel system is corrected, recheck the engine for the E770 event.If the E770 was active and the E363 was not active, there is a problem with the high-pressure fuel pump. Replace the high-pressure fuel pump and the edge filter.Fuel Temperature Sensors
Use Cat ET to monitor the "Fuel Temperature" and the "Fuel Rail Temperature" parameters. Ensure that the value for each of these status parameters is reasonable.