818644 2 Mercury CLAMP

Note: Use this procedure only if the engine shut down completely and it was necessary to restart the engine.Probable Causes
Active diagnostic codes or engine events
Incorrect parameters for engine rating
Poor electrical connections to the Electronic Control Module (ECM)
Poor electrical connections to the unit injector connectors
Faulty remote shutdown switch
Tripped circuit breakers
Fuel supply
Faulty overspeed verify switch (if applicable)Note: If the problem only occurs under certain conditions such as high engine speed, full load or engine operating temperature, then perform the test under those operating conditions.Recommended Actions
Active Diagnostic Codes or Engine Events
Certain diagnostic codes and/or event codes may cause the engine to shutdown. Connect the Caterpillar Electronic Technician (ET) and check for active codes and/or for logged codes. Troubleshoot any codes that are present before continuing with this procedure.Incorrect Parameters for Engine Rating
The engine may be shut down due to low pressure levels or other factors. Connect Cat ET and check for active shutdowns or diagnostic codes.If a shutdown is active, "Injection Disabled" will appear on Cat ET.An engine shutdown event will appear on a CAN J1939 device if the device is capable of displaying diagnostic codes.Poor Electrical Connections to the ECM
Check the associated wiring for the following conditions: damage, abrasion, corrosion and incorrect attachment .
J1/P1 and J2/P2 ECM connectors
J61/P61 Customer connector
J401/P401 and J402/P402 Engine Speed/Timing Sensor connectorsRefer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Check Cat ET for an active 168-02 "System Voltage intermittent/erratic".Check the battery connection at the J61 customer connector and the ECM connector. Perform a pull test on the pin locations at the ECM that are associated with the +Battery and the −Battery connections. Refer to the diagnostic functional test Troubleshooting, " Electrical Connectors - Inspect".Note: Aftermarket engine protection devices usually interrupt power to the ECM. Check for correct installation and for operation of aftermarket engine protection devices. It may be necessary to bypass aftermarket devices in order to continue testing.Poor Electrical Connections to the Unit Injector Connectors
Check the J300/P300 valve cover connectors and associated wiring for the following conditions: damage, abrasion, corrosion and incorrect attachment. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".Faulty Remote Shutdown Switch
Access a status screen in Cat ET that displays the remote shutdown switch status. The remote shutdown switch status on Cat ET is called "User Shutdown".
Table 1
"User Shutdown Status"     Switch Status     Measured Voltage at P61-27    
ON     Negative battery     <0.9 VDC    
OFF     Open circuit     >10 VDC    If the voltage is not in the proper range, refer to the diagnostic functional test Troubleshooting, "Switch Circuits - Test".Tripped Circuit Breakers
Check the circuit breakers. The circuit breakers may exceed the trip point due to overheating. Reset the circuit breakers if the circuit breakers are tripped.Fuel Supply
Check for a problem with the fuel supply and verify the fuel pressure. Verify that the fuel pressure sensor is installed. Refer to Systems Operation/Testing and Adjusting for additional information.Faulty Overspeed Verify Switch
If an overspeed condition has occurred, the air shutoff solenoid(s) must be reset manually. Remove wire for the overspeed verify switch from the ECM connector and test again. If the problem goes away, there is a problem in the circuit for the overspeed verify switch. Refer to the diagnostic functional test Troubleshooting, "Switch Circuits - Test".