ACTUATOR GP-PUMP 5604509 - Caterpillar

Probable Causes
Active engine shutdown
Electrical connectors
Circuit breaker
Engine speed/timing signal
Fuel supply
Spark plugRecommended Repairs
Active Engine Shutdown
Use the Caterpillar Electronic Technician (ET) to check for any active engine shutdowns and/or logged engine shutdowns. Determine the reason for the shutdown. After correcting the problem, set the engine control to the OFF/RESET mode for at least 15 seconds before you try to restart the engine.Electrical Connectors
Check the wiring harnesses and the connectors. Inspect the connectors in the terminal boxes. Inspect the power supply connections and the ground. Refer to Troubleshooting, "Inspecting Electrical Connectors".
Use Cat ET to check for the 168-02 diagnostic code for "System Voltage Intermittent". If this diagnostic code is logged, proceed to Troubleshooting, "Electrical Power Supply".
Inspect the wiring from the power supply to the electronic control modules. Refer to the Electrical System Schematic. Check the power and ground connections to the electronic control modules. Refer to Troubleshooting, "Electrical Power Supply" for more information.Circuit Breakers
Check the 16 amp circuit breaker in the terminal box for the master electronic control module. The circuit breaker may exceed the trip point due to overheating. Reset the circuit breaker if the circuit breaker is tripped.Engine Speed/Timing Signal
Loss of the signal from the speed/timing sensor will cause a shutdown. Use Cat ET to check for logged diagnostic codes. For more information, refer to Troubleshooting, "Engine Speed/Timing Sensor".Fuel Supply
Check the fuel lines for the following problems: restrictions, obstructions, collapsed lines and pinched lines. If problems are found with the fuel lines, repair the lines and/or replace the lines.
Check the restriction of the fuel filter. If the fuel pressure is low, replace the fuel filter.
Check the fuel quality.
Check the fuel pressure. Refer to Systems Operation/Testing and Adjusting, "Fuel System" for the correct pressure values. If the fuel pressure is still low, check the gas regulator and the fuel metering valve.Spark Plug
An engine shutdown that is due to a faulty spark plug is likely to occur when the engine is operating under a load. Refer to Troubleshooting, "Ignition Transformers Secondary Circuit and Spark Plugs".