TIP GP-SHORT 8J4954 - Caterpillar

Expected Result:The continuity of the circuits between the terminals is good.The continuity between the terminals and the ground strap is open.Results:
OK - The continuity of the circuits is good. The continuity of the circuit between the master ECM and the ground strap is open.Repair: Perform the following steps:
Switch the 35 amp circuit breaker ON. Set the engine control to the STOP mode.
Observe the "Active Diagnostic Codes" screen of Cat ET.If a "1446-9 Fuel Metering Module : Abnormal Update Rate" diagnostic code is activated, troubleshoot the CAN data link. Refer to the engine's schematic diagram. If a 1446-9 diagnostic code is not activated, proceed to Test Step 7.
Not OK - At least one of the following conditions is found: There is an open circuit between the plug for the master ECM and the plug for the fuel metering valve. There is a short circuit between the plug for the master ECM and a component that is at ground potential.Repair: Perform the necessary repairs to the wiring and/or connectors. Replace parts, if necessary. Ensure that all of the seals are properly installed. Ensure that the connectors are properly engaged. Verify that the repair has eliminated the original problem.STOPTest Step 5. Check the Signal for the Fuel Flow
Set the engine control to the OFF/RESET mode. Switch the 35 amp circuit breaker OFF.
Insert two 7X-1710 Multimeter Probes into the harness side of the P1 connector. Insert the first probe into terminal 58. Insert the second probe into terminal 60. Use a multimeter that is capable of measuring the frequency and the duty cycle. Connect the multimeter to the probes.
Switch the 35 amp circuit breaker ON. Set the engine control to the STOP mode.
Measure the DC voltage, the duty cycle, and the frequency of the signal for the fuel flow.Expected Result:The DC voltage is between 13.7 and 15.7.The duty cycle is between 92 and 98 percent.The frequency is between 175 and 185 hertz.Results:
OK - The voltage, the duty cycle, and the frequency of the signal for the fuel flow is correct at the master ECM P1 connector. There is a problem with the fuel metering valve.Repair: Replace the fuel metering valve. Verify that the repair has eliminated the original problem.STOP
Not OK - The voltage, the duty cycle, and/or the frequency of the signal for the fuel flow is not correct at the master ECM P1 connector. Proceed to Test Step 6.Test Step 6. Check the Continuity of the Circuit for the Fuel Flow
Set the engine control to the OFF/RESET mode. Switch the 35 amp circuit breaker OFF.
Disconnect the J1/P1 connector.
Disconnect the fuel metering valve J24/P24 connector.
Illustration 5 g01534173
Connections for the circuit for the fuel metering valve (P1) Connector for the ECM (P24) Connector for the fuel metering valve (P1-58) Signal for the fuel flow (P1-60) Return for the signal for the fuel flow (P24-S) Signal for the fuel flow (P24-T) Return for the signal for the fuel flow
Use a multimeter to check the continuity of the following circuits:
P1-58 and P24-S
P1-58 and the ground strap