DOWEL 3F1953 - Caterpillar

System Operation Description:Table 1 lists the diagnostic codes that relate to the Aftertreatment Regeneration Devices absolute air pressure.Note: Some of the following codes may not be applicable for certain applications.
Table 1
Diagnostic Trouble Codes    
CDL Code    J1939 Code    Description    Comments    
E1170 (1)     3837-17     Low Aftertreatment #1 Secondary Air Pressure     Air pressure to the combustion air valve is low.    
E1170 (2)     3837-18     Low Aftertreatment #1 Secondary Air Pressure     Air pressure to the combustion air valve is low.    
Follow the troubleshooting procedure in order to identify the root cause of the problem.    System OperationNote: The technician must perform a combustion air test in order to verify that the problem is corrected. If the problem has been resolved, perform a service regeneration before the unit is returned to service.The combustion air system consists of the following components:
Combustion air valve controller
Combustion air valve
Absolute pressure sensorThe combustion air valve controller receives operating voltage from the applications control system. The controller receives commands from the engine Electronic Control Module (ECM) via a CAN data link. The controller converts the commands from the ECM into a command signal for the combustion air valve. The controller also provides 5 VDC to the valve position sensor.The combustion air valve positions an actuator according to the commands from the controller. The position sensor sends a signal to the controller. The signal indicates the position of the actuator.The combustion air valve controller sends the position of the actuator to the engine ECM via the CAN data link. The position of the actuator can be viewed on Caterpillar Electronic Technician (ET). The controller also sends diagnostic information to the ECM.The absolute pressure sensor converts the absolute pressure of the combustion air into an electrical signal. The ECM uses the signal to determine the volume of combustion air that is being provided to the ARD. The ECM changes the command to the combustion air controller until the volume of combustion air is correct.
Illustration 1 g03777701
CEM (typical) (1) Piping for the combustion air (2) Combustion air valve (3) Pressure sensor for the inlet of the combustion air (4) DPF differential pressure sensor (5) Cable for CEM connector to the ECM (6) Actuator for the combustion air valve (7) Inlet for the combustion air valve (8) Inlet for the combustion air to the ARD head (9) ARD head
Table 2
Troubleshooting Test Steps     Values     Results    
1. Check for Associated Diagnostic Trouble Codes
A. Download the "Warranty Report" from the engi