WHEEL (IMPELLER) 1T0270 - Caterpillar

Table 1 lists the diagnostic codes that relate to the combustion air system.Note: Some of the following codes may not be applicable for certain applications.Clear all "Active" codes using Cat ET before proceeding with the following procedure. Refer to Troubleshooting, "Diagnostic Capabilities - Clearing Active Codes for On Board Diagnostics (OBD)" for more information on clearing "Active" codes.
Table 1
Diagnostic Trouble Codes    
CDL Code    J1939 Code    Description
(code descriptions may vary)    Comments    
2489-5     3487-5     ARD Air Pressure Control Actuator : Current Below Normal     There is low current flow in the wiring between the combustion air valve and the combustion air valve controller. Regenerations are disabled. The code is logged. Engine power is derated.    
2489-6     3487-6     ARD Air Pressure Control Actuator : Current Above Normal     There is excessive current flow in the wiring between the combustion air valve and the combustion air valve controller. Regenerations are disabled. The code is logged. Engine power is derated.    
2489-7     3487-7     ARD Air Pressure Control Actuator : Not Responding Properly     The combustion air valve is not responding properly to commands from the combustion air valve controller. The code is logged. Engine power is derated.    
2489-8     3487-8     ARD Air Pressure Control Actuator : Abnormal Frequency, Pulse Width, or Period     The combustion air valve is not responding properly to commands from the combustion air valve controller. The code is logged. Engine power is derated.    
2490-3     3488-3     ARD Air Pressure Control Actuator Position Sensor : Voltage Above Normal     There is excessive voltage on the signal wire between the combustion air valve and the combustion air valve controller. The code is logged. Engine power is derated.    
2490-4     3488-4     ARD Air Pressure Control Actuator Position Sensor : Voltage Below Normal     There is low voltage on the signal wire between the combustion air valve and the combustion air valve controller. The code is logged. Engine power is derated.    
3471-5     5591-5     ARD Air Pressure Control Module : Current Below Normal     There is low current flow in the wiring between the engine ECM and the combustion air valve controller. The code is logged.    
3471-6     5591-6     ARD Air Pressure Control Module : Current Above Normal     There is excessive current flow in the wiring between the engine ECM and the combustion air valve controller. The code is logged.    
3472-3     5591-3     ARD Air Pressure Control System : Voltage Above Normal     There is excessive voltage on the voltage supply wire to the combustion air valve controller. The code is logged. Engine power is derated.    
3472-4     5591-4     ARD Air Pressure Control System : Voltage Below Normal     There is low voltage on the voltage supply wire to the combustion air valve controller. The code is logged. Engine power is derated.    
3472-9     5591-9     ARD Air Pressure Control System : Abnormal Update Rate