HEAD GP- 20R2648 - Caterpillar

Use this procedure to troubleshoot a low dosing air assist pressure. Also, use this procedure if one of the following event codes is active or logged.
Table 1
J1939 Code and Description CDL Code and Description Comments
4335-17
Aftertreatment #1 SCR Dosing Air Assist Absolute Pressure : Low - least severe (1) E964 (1)
Low Aftertreatment #1 SCR Dosing Atomization Air Assist Pressure The air pressure is below the trip point for the programmed delay time.
Dosing is disabled until the pressure is correct.
The code is logged.
4335-18
Aftertreatment #1 SCR Dosing Air Assist Absolute Pressure : Low - moderate severity (2) E964 (2)
Low Aftertreatment #1 SCR Dosing Atomization Air Assist Pressure The air pressure is below the trip point for the programmed delay time.
Dosing is disabled until the pressure is correct.
The code is logged.
Table 2
Associated Codes
J1939 Code CDL Code Troubleshooting Procedure
4335-3 3092-3 Troubleshooting, "Sensor Signal (Analog, Active) - Test"
4335-4 3092-4 Troubleshooting, "Sensor Signal (Analog, Active) - Test"
4336-5 3094-5 Troubleshooting, "Solenoid Valve - Test"
4336-6 3094-6 Troubleshooting, "Solenoid Valve - Test" Probable Causes
Codes
Leaks
Air pressure
SensorRecommended Actions
Table 3
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Apply electrical power to