BEARING 9J5942 - Caterpillar

Use this procedure to troubleshoot a low exhaust temperature. Also, use this procedure if one of the following event codes is active or logged.Probable Causes
Codes
Exhaust System
Deposits or Buildups
Table 1
J1939 Code and Description CDL Code and Description Comments
2434-1
Engine Exhaust Manifold Bank #1 Temperature #1 : Low - most severe (3) E323(3)
Low Exhaust Temperature The ECM has detected Hydrocarbon levels in SCR Catalyst. Operator will be alerted to elevate exhaust temperatures. Refer to Operation and Maintenance Manual, Engine Operation - Hydrocarbon Release Procedure.
2434-18
Engine Exhaust Manifold Bank #1 Temperature #1 : Low - most severe (2) E323(2)
Low Exhaust Temperature
3241-1
Low Exhaust Temperature E1691(3)
Low Exhaust Temperature The ECM has detected high Urea Deposit levels in SCR Catalyst. Operator will be alerted to elevate exhaust temperatures.
Follow the recommended action in the Table 2 for Urea Deposit Release.
3241-18
Low Exhaust Temperature E169(2)
Low Exhaust Temperature Recommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Turn the DC breaker to the ON position.
B. Connect Cat Electronic Technician (ET) to the service tool connector.
C Look for active codes that are associated with the engine to check for engine health.
Codes
Result: An associated code is active.
Repair: Troubleshoot any associated codes before continuing with this test.
Result:A low exhaust temperature code is active or logged.
Proceed to Test Step 2.
2. Inspect the Exhaust System
A. Turn the DC breaker to the OFF position.
B. Visually inspect the exhaust system from the turbocharger out to the tailpipe out.
Exhaust System
Result: The exhaust system is OK.
Proceed to Test Step 3.
Result: The exhaust system is NOT OK.
Repair or replace damaged exhaust components. Reference Disassembly and Assembly Manual.
If the problem is not resolved, proceed to Test Step 3.
3. Run Thermal Management
A. Refer to the Operation and Maintenance Manual, Engine Operation - Deposit Release Procedure.
Thermal Management
Result: The code is cleared. Verify that the problem is eliminated.
Result: A low exhaust temperature code is active.
Proceed to Test Step 4.
4. Inspect the DEF Injector and Mixing Tube
A. Turn the DC Breaker to the OFF position.
B. Remove DEF Injector and inspect for external deposit buildup.
C. Inspect Mixing Tube and check for deposit buildup.
D. Inspect the face of the SCR catalyst for the following with a borescope:
- Oil
- Fuel
- Urea Deposits
Deposits or Buildup
Result: Transparent or less than 1 mm deposits are present on the tip of the injector.
Repair: Clean the injector with water (not sea water).
Reinstall the injector into the exhaust stream replacing the injector seal.
Proceed to Test Step 5.
Result: White or brown deposits, or deposits larger than 1mm are present on the injector.
Repair: Replace the DEF injector.
Proceed to Test Step 5.
Result: The SCR catalyst face has oil fuel, or soot buildup.
- For Oil, refer your Engine Troubleshooting related to Troubleshooting, "Exhaust System Contains Oil" for additional information.
- For Fuel, refer your Engine Troubleshooting related to TroubleshootingExhaust System Contains Fuel for additional information.
5. Connect CAT ET and follow the steps reset the code Manually
A: Turn the breaker to the ON position.
B: Connect CAT ET.
C: Navigate to Service > Service Procedures > Aftertreatment #1 SCR Estimated Diesel Exhaust Fluid Deposit Reset.
D: Click on the reset button at