BODY AS-PISTON 3675160 - Caterpillar

Note: Use this procedure only if the engine shuts down completely and the engine must be restarted.Probable Causes
Active engine shutdown
Electrical connectors or power supply
There is a problem with the input for the keyswitch.
Circuit breaker
Engine speed/timing signal
Fuel supply
Fuel quality
Spark plugRecommended Actions
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 or Power Supply
Check the wiring harnesses and the connectors. Inspect the connectors in the terminal box. Inspect the power supply connections and the ground. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Use Cat ET to check for the 168-02 diagnostic code for erratic system voltage. If this diagnostic code is logged, proceed to Troubleshooting, "Electrical Power Supply - Test".
Inspect the wiring from the power supply to the power distribution box. Inspect the wiring from the power distribution box to the electronic control modules. Check the power and ground connections at each electronic control module. Refer to Troubleshooting, "Electrical Power Supply - Test" for more information.Verify that the Keyswitch Input is Working Properly
An engine shutdown or an engine overspeed may occur due to a problem with the input for the keyswitch for one of the following:
Actuator for the throttle
Actuator for the turbocharger compressor bypass valve
Actuator for the fuel metering valve
Master ECMVerify that the input for the keyswitch to the actuators is battery voltage when the mode switch is not in the OFF/RESET position.The master ECM will be shutdown and the master ECM will indicate a status of "OFF" when the keyswitch input is low. Circuit Breakers
Check the 35 amp circuit breaker on the power distribution box. 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 engine speed/timing sensor will cause a shutdown. Use Cat ET to check for logged diagnostic codes. For more information, refer to Troubleshooting, "Speed/Timing - Test".Fuel Supply
Use Cat ET to check that the engine fuel parameters are correct for the fuel that is being used. If necessary, perform fuel analysis in order to confirm the fuel quality.Verify that the fuel pressure is correct. When possible, interview the operator in order to determine if fuel quality is in question. Try to determine if the source of the fuel has been changed.Ensure that fuel is supplied at a sufficient pressure that is stable. Check that the size of the fuel line is sufficient. Inspect the fuel system for leaks.The following conditions can affect engine starting:
Low fuel pressure
High fuel pressure
Poor fuel qualityInspect the following fuel system components:
Fuel filter
Gas pressure regulator
Gas shutoff valve
Fuel metering valveVerify that the system components are operating correctly.Repair suspect components. Replace the fuel filter, if necessary.Fuel Quality
Compare the Low Heat Value (LHV) of the gas supply to the "Fuel Quality" parameter that is programmed by the customer into