MOTOR GP-ELEC 0R4320 - Caterpillar

Use this procedure to troubleshoot a problem with NOx Reduction System (NRS). Also, use this procedure if one of the following diagnostic codes is active or easily repeated.
Table 1
J1939 Code and Description CDL Code and Description Comments
411-15
Engine Exhaust Gas Recirculation Differential Pressure : High - least severe (1) E1094 (1)
High EGR Differential Pressure The Electronic Control Module (ECM) detects an abnormally high reading from the NOx Reduction System (NRS) differential pressure sensor.
411-17
Engine Exhaust Gas Recirculation Differential Pressure : Low - least severe (1) E1093 (1)
Low EGR Differential Pressure The ECM detects an abnormally low reading from the NRS differential pressure sensor.
2659-15
Engine Exhaust Gas Recirculation Differential Pressure : High - least severe (1) E1096 (1)
High EGR Mass Flow Rate The ECM detects a higher than desired flow rate through the NRS.
2659-17
Engine Exhaust Gas Recirculation (EGR) Mass Flow Rate : Low - least severe (1) E1095 (1)
Low EGR Mass Flow Rate The ECM detects a lower than desired flow rate through the NRS.
3358-16
Engine Exhaust Gas Recirculation Inlet Pressure : High - moderate severity (2) E1090 (2)
High EGR Intake Pressure The ECM detects the NRS inlet pressure is abnormally high. Note: Exhaust Gas Recirculation (EGR) is an industry standard term used to describe the recirculation of exhaust gas through the engine as a means to reduce "NOx" emissions. Caterpillar has elected to refer to this system as the NOx Reduction System (NRS). Diagnostic codes are regulated by SAE, therefore, the diagnostic codes still reflect the EGR nomenclature.
Table 2
Associated Codes
J1939 Code CDL Code Troubleshooting Procedure
411-3 3387-3 Troubleshooting, "Sensor Signal (Analog, Active) - Test"
411-4 3387-4 Troubleshooting, "Sensor Signal (Analog, Active) - Test"
411-13 3387-13 Troubleshooting, "Sensor Calibration Required - Test"
412-3 3386-3 Troubleshooting, "Sensor Signal (Analog, Passive) - Test"
412-4 3386-4 Troubleshooting, "Sensor Signal (Analog, Passive) - Test"
412-15 E1092 (1) Troubleshooting, "NRS Exhaust Gas Temperature Is High"
412-16 E1092 (2) Troubleshooting, "NRS Exhaust Gas Temperature Is High"
2791-5 3405-5 Troubleshooting, "Solenoid Valve - Test"
2791-6 3405-6 Troubleshooting, "Solenoid Valve - Test"
3358-3 3385-3 Troubleshooting, "Sensor Signal (Analog, Active) - Test"
3358-4 3385-4 Troubleshooting, "Sensor Signal (Analog, Active) - Test"
3358-13 3385-13 Troubleshooting, "Sensor Calibration Required - Test"
3821-5 3618-5 Troubleshooting, "Solenoid Valve - Test"
3821-6 3618-6 Troubleshooting, "Solenoid Valve - Test"
Illustration 1 g06203940
(1) EGR cooler
(2) EGR absolute pressure
(3) EGR Delta P
(4) EGR valve
(5) Venturi
(6) Exhaust Restriction Valve (ERV)
Illustration 2 g06210532
(1) EGR cooler
(2) EGR absolute pressure
(3) EGR Delta P
(4) EGR valve
(5) Venturi
(7) EGR temperature
Table 3
Troubleshooting Test Steps Values Results
1. Check the NRS Components for Oil Leaks
A. Turn the keyswitch to the OFF position.
B. Inspect the following NRS components:
- "NOx Reduction System" (NRS) Valve and oil line connections
- "Exhaust Restriction Valve" (ERV) and oil line connections
Leaks
Result: No oil leaks were found in the system.
Proceed to Test Step 2.
Result: Oil leaks were found in the system.
Repair: Repair the oil leaks.
Proceed to Test Step 2.
2. Check the NRS for Leaks
A. Inspect the following NRS components:
- Exhaust manifold
- Connections for NRS cooler inlet and NRS cooler outlet
- NRS venturi inlet and outlet connections
- Port locations for NRS differential pressure sensor and NRS absolute pressure sensor
- Connections for NRS valve and ERV