C7.1 Engines and Generator Sets Caterpillar

Fuel Temperature Is High

Usage:

C7.1 770

If either of the following diagnostic trouble codes are active, perform the procedure that follows:

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Table 1
Diagnostic Trouble Codes for Fuel Temperature Is High
J1939 Code	CDL Code	Code Description (Code descriptions may vary)	Comments
174-15	E363 (1)	Engine Fuel Temperature 1 : High - least severe (1)	The temperature of the low-pressure fuel in the high-pressure fuel pump is high. The ECM has been powered for at least 2 seconds. The engine has been operating for at least 185 seconds. There are no other faults in the electrical system. The warning lamp will come on. The warning lamp will go off when the temperature drops below the trip point.
174-16	E363 (2)	Engine Fuel Temperature 1 : High - moderate severity (2)	The temperature of the low-pressure fuel in the high-pressure fuel pump is high. The ECM has been powered for at least 2 seconds. The engine has been operating for at least 185 seconds. There are no other faults in the electrical system. The warning lamp will come on. The engine may be derated by 20%. The warning lamp will go off when the temperature drops below the trip point for 15 seconds.

Probable causes

Incorrect position of fuel shut-off valves
Fuel level in tank
Return fuel cooler
Return fuel lines
Location of the fuel tank

Note: The procedures have been listed in order of probability. Complete the procedure in the order in which the steps are listed.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Check for Active or Logged Diagnostic Codes A. Establish communication between the electronic service tool and the Electronic Control Module (ECM). Refer to Troubleshooting, "Electronic Service Tools", if necessary. B. Download the Warranty Report and the Product Status Report with Histograms before performing any troubleshooting or clearing any diagnostic codes. Note: The downloaded information will be required by the Dealer Solutions Network (DSN) if troubleshooting assistance is needed. C. Use the electronic service tool to check for active or logged codes.	Diagnostic Active or Logged codes	Result: A diagnostic code is active or logged other than a 174-XX (E363-X) code. Repair: Troubleshoot the active or logged code. Result: A 174-XX (E363-X) diagnostic code is active or logged. Proceed to Test Step 2.
2. Fuel Shut-off Valves A. Check the position of any fuel shut-off valves in the feed lines between the fuel tank and the engine. B. Check the position of any fuel shut-off valves in the return lines between the engine and the fuel tank.	Fuel valves	Result: A fuel shut-off valve is not fully open. Repair: Move all shut-off valves to the fully open position. Result: All shut-off valves are in the fully open position. Proceed to Test Step 3.
3. Fuel Level in Tank Note: If the level in the fuel tank is low, the hot return fuel can raise the temperature in the fuel tank. A. Check the fuel level in the tank.	Fuel level	Result: The fuel level in the tank is low. Repair: Replenish the fuel tank at the earliest opportunity. Result: The fuel level in the tank is OK. Proceed to Test Step 4.
4. Return Fuel Cooler A. Check that the fins on the return fuel cooler are not blocked with dirt or debris. Make sure that the fins are not bent or missing.	Return fuel cooler	Result: The fins on the return fuel cooler are blocked with dirt or debris. Repair: Clean the return fuel cooler. Result: The fins on the return fuel cooler are bent or missing. Repair: Install a replacement return fuel cooler. Result: The return fuel cooler is OK. Proceed to Test Step 5.
5. Return Fuel Lines A. Check the return fuel lines for blockages or restrictions.	Return fuel lines	Result: A return fuel line is blocked or restricted. Repair: Clear the fuel line or replace the line. Result: The return fuel lines are OK. Proceed to Test Step 6.
6. Location of the Fuel Tank A. Make sure that the fuel tank is not close to a heat source.	Fuel tank location	Result: The fuel tank is close to a heat source. Repair: Shield the fuel tank from the heat source. Result: The fuel tank is not close to a heat source. Contact the Dealer Solutions Network (DSN).