STEERING VALVE GROUP 7J0966 - Caterpillar

Probable Causes
Active engine shutdown
Electrical connectors
Circuit breakers
Engine speed/timing
Fuel supplyRecommended Actions
Active Engine Shutdown
Use ET to check for active engine shutdowns and/or for logged engine shutdowns. Determine the reason for any shutdowns. After the problem is corrected, cycle the keyswitch to the OFF/RESET position for at least 15 seconds before you try to restart the engine.Electrical Connectors
Check for the correct installation of the following connectors: J1/P1 ECM connector, J2/P2 ECM connector, customer connector and engine speed/timing sensor connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Use ET to check for logged diagnostic codes for the circuit for the electrical power supply. If a diagnostic code is logged, proceed to Troubleshooting, "Electrical Power Supply Circuit - Test".
Inspect the battery wires from the ECM back to the battery compartment. Refer to the Electrical System Schematic. Inspect the wires and the power relay. Check the power and ground connections to the ECM. Refer to Troubleshooting, "Electrical Power Supply Circuit - Test" for more information.Circuit Breakers
Check the circuit breakers for the engine. The circuit breakers may exceed the trip point due to overheating. Reset the circuit breakers if the circuit breakers are tripped.Engine Speed/Timing
Use ET to check for Logged Diagnostic Codes for the engine speed/timing sensors. Refer to Troubleshooting, "Engine Speed/Timing Sensor Circuit - Test" for more information.Fuel Supply
Check the fuel lines for the following problems: restrictions, collapsed lines and pinched lines. If problems are found with the fuel lines, repair the lines and/or replace the lines.
Check the fuel tank for foreign objects which may block the fuel supply.
Check for air in the low pressure fuel supply system if any of the following procedures have been performed:
Replacement of the fuel filters
Service on the low pressure fuel supply circuit
Replacement of unit injectorsNote: A sight glass in the low pressure supply line is helpful in diagnosing air in the fuel. Refer to Testing and Adjusting for more information.
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
Purge air from the low pressure fuel supply circuit. Refer to Operation and Maintenance Manual, "Fuel System - Prime" for the correct procedure.
Check fuel quality. In temperatures below 0 °C (32 °F), check for solidified fuel (wax). Refer to Special Instruction, SEBD0717, "Diesel Fuels And Your Engine".
Check the fuel pressure after the fuel filter while the engine is being cranked. Refer to Testing and Adjusting for the correct pressure values. If the fuel pressure is low, replace the fuel filters. If the fuel pressure is still low, check the following items: fuel transfer pump, fuel transfer pump coupling and fuel pressure regulating valve. Refer to Testing and Adjusting for more information.