BIT (L.H.) 3G7764 - Caterpillar

Use this procedure in order to troubleshoot high inlet air temperature or use this procedure if one of the following diagnostic codes are active. Refer to Systems Operation, "Engine Monitoring Parameters" for information about engine events. Access the engine monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these codes. For information on the engine monitoring system, refer to Systems Operation, "Engine Monitoring System".
Table 1
Diagnostic Code
Description Conditions which Activate the Code System Response
105-0 Engine Intake Manifold #1 Temperature : High - most severe (3) The inlet air temperature has exceeded the trip point for the programmed delay time. The code is logged.
The red stop lamp is illuminated.
The engine is shut down.
105-15 Engine Intake Manifold #1 Temperature : High - least severe (1) The code is logged.
The amber warning lamp is illuminated. Probable Causes
High ambient air temperature
High coolant temperature
High inlet air restriction and/or high altitude
Faulty intake manifold air temperature sensor and/or circuit
Insufficient flow of cooling water through the aftercooler (if equipped)
Insufficient flow of air through the aftercooler (if equipped)Recommended 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. Modify the inlet air system in order to supply intake air that is within specifications, if necessary.High Coolant Temperature
Check for a high coolant temperature.Refer to Troubleshooting, "Coolant Temperature Is High".High Inlet Air Restriction and/or High Altitude
If the engine is equipped with a turbocharger, an inlet restriction causes the turbocharger to work harder. This increases inlet air temperature.Measure the inlet air pressure while the engine is operating under load. For specific data, refer to the performance data sheet for your 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
Check the Performance Data Sheet for specifications that are related to the operating altitude for this engine.Faulty Intake Manifold Air Temperature Sensor and/or the Circuit
Allow the engine to cool. Remove the sensor from the engine. Use Cat ET to check the status of the "Inlet Air Temperature" parameter. Compare the reading to the ambient air temperature. If the sensor is OK, the readings will be comparable.If the readings are not comparable, troubleshoot the circuit for the intake manifold air temperature sensor. Refer to Troubleshooting, "Sensor Signal (Analog, Passive) - Test".Insufficient Flow of Cooling Water through the Aftercooler (if equipped)
Note: For two-stage aftercoolers, be sure to check both sections.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 for the aftercooler. A high temperature differential indicates an insufficient flow rate.If there is a high differential between the inlet temperature and the outlet temperature of the coolant for the aftercooler, perform the following procedure:
Check the water circuit of the aftercooler for obstructions.
Check the pump for proper operation.Ensure that the system pressure is adequate. If a restriction