TURBOCHARGER GP 7W7125 - Caterpillar

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Illustration 1 g00515350
Upper Display With AL Fault Code "AL3" An alarm fault informs the operator of a condition that could cause a dedicated fault shutdown. An alarm fault precedes certain dedicated shutdown faults. Alarm faults are activated automatically by the GSC and the faults depend on certain setpoints. The GSC does not record alarm faults in the fault log.When an alarm fault occurs, the GSC FLASHES the fault alarm indicator. The corresponding alarm code is shown on the upper display after the alarm codes key is pressed. When the alarm fault is no longer active, the alarm fault code is no longer shown on the upper display.
Table 1
AL Fault Code Troubleshooting    
AL Fault Code    Description    Troubleshooting    
AL1     High Water Temperature Alarm
Coolant temperature increases to within
6°C (11°F)of setpoint P15     See Testing And Adjusting, "Troubleshooting Dedicated Shutdown Indicators".    
AL2     Alarm for Low Engine Coolant Temperature
Coolant temperature decreases to setpoint P16.     See Testing And Adjusting, "Troubleshooting Dedicated Shutdown Indicators".    
AL3     Alarm for Low Engine Oil Pressure.
Oil pressure drops to within
34 kPa (5 psi) of the P13 or P14 setpoint.     See Testing And Adjusting, "Troubleshooting Dedicated Shutdown Indicators".    
AL4     Fault Is Detected By The Engine ECM
Engine ECM detects an alarm or a shutdown fault.     Refer to the appropriate Service Manual, "Engine Troubleshooting".    Troubleshooting Procedure
If the operation of the AL fault codes is suspected to be incorrect, perform this procedure.
Check For A Diagnostic Fault.
Check for an active CID 110 diagnostic code or a CID 269 diagnostic code. See Testing And Adjusting, "Troubleshooting Diagnostic Fault Codes".Expected Result: CID 110 or CID 269 should not be showing.Results:
OK - Proceed to next step.
NOT OK - Correct the active CID 110 or CID 269 prior to proceeding with this procedure. See Testing And Adjusting, "Troubleshooting Diagnostic Fault Codes". STOP.
Identify The AL Fault Code That Is Suspected To Be Incorrect.
If AL fault code AL1 or AL3 is suspected to be incorrect, then see Testing And Adjusting, "Troubleshooting Dedicated Shutdown Indicators".
If AL fault code AL2 is suspected to be incorrect, go to 3.
Check Low Engine Coolant Temperature Function.
Note the setpoint P16 (low water temperature alarm), see Systems Operation, "Setpoint Viewing OP2".
Check and note the actual coolant temperature that is showing on the lower display.
Compare the two temperatures.Expected Results: The actual coolant temperature that is showing on the lower display should be greater than setpoint P16. This actual temperature should not cause an AL2 fault code.Results:
OK - The actual temperature is greater than the setpoint P16 and the alarm fault indicator does not FLASH and AL2 fault code is not showing on the upper display when the alarm code key is pressed. The problem is not present now. The problem may be intermittent. Check the harness and the electrical connections of the circuit for the coolant temperature. See Testing And Adjusting, "Electrical Connector - Test". STOP.
OK - The temperature that is showing on the lower display is greater than setpoint P16. Therefore, the temperatures