HOUSING 9D8772 - Caterpillar

Step 1. CHECK FUEL PRESSURE SWITCH
Remove the signal wire from the EMS fuel pressure switch.
Perform the Output Test. See Output Test.Expected Result:The alarm sounds.Results:
OK - Fuel pressure switch is faulty.Repair: Replace the fuel pressure switch.STOP
NOT OK. - Go to Test Step 2.Test Step 2. CHECK EMS CONTROL AND HARNESS
At the machine harness connection for the switch, measure the voltage (DCV) between the signal circuit and the ground circuit.Note: EMS controls with part numbers 3T-1321 and 3T-3136 should measure 10.0 DCV 0.5 DCV instead of 8.0 DCV 0.5 DCV.Expected Result:Voltage is 8.0 0.5 DCV.Results:
OK - EMS control and harness are correct.
Go to Test Step 3.
NOT OK - The EMS control or harness is faulty. Go to Test Step 4Test Step 3. CHECK ALARM CIRCUIT
Turn the disconnect switch and the key start switch to the OFF position.
Disconnect the machine harness from the EMS control.
At the machine harness connector for the EMS control, place a jumper from connector contact 1 to contact 10.Expected Result:The alarm does not sound.Results:
OK - The harness has an open circuit or the alarm is faulty.Repair: Repair or replace the harness or the alarm.STOP
NOT OK - The EMS control is faulty.Repair: Replace the EMS control. See EMS Control Replacement.STOPTest Step 4. CHECK FUEL PRESSURE SWITCH CIRCUIT
Turn the disconnect switch and the key start switch to the OFF position.
Disconnect the machine harness from the EMS control.
At the machine harness connector for the EMS control, measure the resistance between contact 13 and frame ground.Expected Result:Resistance is less than 5000 ohms.Results:
OK - Harness is faulty.Repair: Repair or replace the harness.STOP
NOT OK - EMS control is faulty.Repair: See EMS Control Replacement.STOP