CONNECTOR 5K9894 - Caterpillar

Use this procedure in order to troubleshoot a problem with high dosing air assist pressure or use this procedure if the following event code is 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
E1969 (1)
High Aftertreatment #1 SCR Dosing Atomization Air Assist Pressure The air pressure is above 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 to Troubleshooting, "Event Codes" for information about event codes.Probable Causes
Pressure regulator for air assist pressure has failed
Plugged DEF injector nozzle
Air assist pressure sensor malfunctionRecommended Actions
Pressure Regulator for Air Assist Pressure
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.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 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.Plugged DEF Injector Nozzle
Check the nozzle for an obstruction.Reference: Refer to Testing and Adjusting, "Dosing Lines Blockage - Test".