ELBOW 7K0498 - Caterpillar

Use this procedure in order to troubleshoot a problem with low dosing air assist pressure. Use this procedure if the following event codes are active. Refer to Troubleshooting, "Event Codes" for information about event codes.
Table 1
Event Code
Code and Description Conditions which Generate this Code System Response
E964 (1)
Low Aftertreatment #1 SCR Dosing Atomization Air Assist Pressure The air pressure is below the trip point for the programmed delay time. The code is logged.
Dosing is disabled until the pressure is correct. Note: Use Cat ET to verify any suspected code. Determine what codes are present. Evaluate all codes for possible interaction. Refer toTroubleshooting, "Diagnostic Trouble Codes" and Troubleshooting, "Event Codes" for direction.Probable Causes
Supply air pressure is low
Leaks in the air assist supply, between the regulator and the nozzle
Pressure regulator for air assist pressure has failed
Air assist valve (solenoid) has failed
Dosing air assist pressure sensor malfunctionRecommended Actions
Perform air assist valve (solenoid) test). Refer to Troubleshooting, "Solenoid Valve - Test".Supply Air Pressure is Low
Check the pressure gauge for the air supply to the dosing cabinetThe cabinet requires a regulated air pressure range of 724 to 1034 kPa (105 to 150 psi ), expressed here as gauge pressure.Leaks in the Air Assist Supply Between the Regulator and the Nozzle
Inspect for leaks and repair when found.Pressure Regulator for Air Assist Pressure has Failed
Note: The air pressure regulator is set at the factory and must not be adjusted. Attempting to adjust the regulator will destroy the regulator. The only service option is to replace the regulator.Monitor the status for "Aftertreatment #1 SCR Dosing Air Assist Absolute Pressure" on Cat ET. This pressure is at the output for the regulator.Activate the "Aftertreatment #1 SCR Dosing Air Assist Valve Command Override" and record the pressure. The pressure must be in the range of 414 kPa to 469 kPa (60 to 68 psi), expressed here as gauge pressure. Replace the regulator if the pressure is out of range.Air Assist Valve (Solenoid) has Failed
Determine if the valve is actuating properly.Dosing Air Assist Pressure Sensor Malfunction
Determine if the air assist pressure sensor is reading correctly. Install a gauge on the air outlet of the cabinet and compare the indicated pressures.Monitor the status for "Aftertreatment #1 SCR Dosing Air Assist Absolute Pressure" on Cat ET. This pressure is at the output for the regulator.Determine if the sensor is reading correctly. Install a gauge on the air outlet of the cabinet and compare the indicated pressures.