GEAR AS-PUMP 9G1497 - Caterpillar

Use this procedure if one of the following event codes is active. Refer to Troubleshooting, "Event Codes" for information about event codes and the default trip points for these codes. You must access the monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these codes.
Table 1
Event Code    
Description    Conditions which Activate the Code    System Response    
E027(1) High Inlet Air Temperature Warning     The crank terminate relay is set and the engine has been running for at least 30 seconds. The inlet air temperature has exceeded the trip point and the delay time has expired. No other codes for the inlet air temperature are active.     The alarm output is activated. The code is logged.    
E026(3) High Inlet Air Temperature Shutdown     The shutdown output is activated. The code is logged. Probable Causes
High ambient air temperature
High temperature of the coolant for the separate circuit
Lean operation
High inlet air restriction and/or high altitude
Faulty inlet air temperature sensor and/or circuit
Insufficient flow of cooling water through the aftercoolerRecommended Actions
High Ambient Air Temperature
Determine if the ambient air temperature is within the design specifications for the cooling system.Determine the cause of the high air temperature. Make corrections, when possible.Coolant Temperature
Refer to Troubleshooting, "Coolant Temperature Is High".Lean Operation
If the air/fuel mixture is too lean, compression of the higher volume of air through the turbocharger will increase the temperature. Correct the air/fuel ratio.Check for High Inlet Air Restriction and/or High Altitude
When inlet air pressure is low, the turbocharger works harder in order to achieve the desired inlet manifold pressure. This increases inlet air temperature.Measure the inlet air pressure while the engine is operating under load. For specific data, refer to the Technical Marketing Information for the engine.Inlet Air Restriction
Check for plugged air filters. Check for obstructions to the air inlet. Replace the air filters and/or remove the obstruction from the air inlet.High Altitude
Make sure that the settings for the engine are correct for the altitude.Make sure that the load rating is correct for the altitude.Check the Temperature Sensor and/or the Circuit
Allow the sensor to cool and remove the sensor. Check the reading for the inlet air temperature. If the sensor is OK, the reading and the ambient temperature are approximately equal.If the reading is not correct, switch the sensor with a sensor that is known to be good. Verify that the problem is solved.Check for Sufficient Flow of Cooling Water through the Aftercooler
Check the inlet temperature of the coolant for the aftercooler. Compare the reading to the regulated temperature. If the temperature is OK, check the outlet temperature of the coolant. A high temperature differential indicates an insufficient flow rate.Make sure that the performance of the radiator or the heat exchanger is correct.If there is a high differential between the inlet temperature and the outlet temperature of the coolant for the aftercooler, perform the following procedures:
Check the water circuit of the aftercooler for obstructions.
Make sure that the water temperature regulators are operating properly.
Check the water