HOSE AS 3147649 - Caterpillar

Probable Causes
Engine duty cycle
DEF injector
Exhaust system insulation
Incorrect Selective Catalytic Reduction (SCR) inlet temperatureRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Illustration 1 g03861965
Typical example of "Total Time vs Engine Speed and Engine Load Factor" table from the "Product Status Report"
Table 1
Troubleshooting Test Steps Values Results
1. Download the "Product Status Report" Using the Electronic Service Tool.
A. Connect the electronic service tool to the engine ECM.
B. Down load the "Product Status Report".
C. Record the configured low idle speed.
D. Refer to Illustration 1. Calculate the percentage of time that the engine has operated in area (1).
Product status report
The engine has operated for too long at low speed or low load if one of the following statements is true:
The configured idle speed is between 800 rpm and 990 rpm and the time spent in area (1) is greater than 15 percent
The configured idle speed is between 1000 rpm and 1200 rpm and the time spent in area (1) is greater than 45 percent
The configured idle speed is between 1000 rpm and 1200 rpm and the time spent in area (1) excluding the 1000 rpm to 1400 rpm area is greater than 15 percent
Result : The engine has operated for too long at low speed or low load.
Repair: Refer to Illustration 1. Operate the engine in Area (2) for 10 hours. Operating the engine in this range will increase exhaust temperatures and remove DEF deposits. Check the exhaust system for deposits again after 10 hours. In order to avoid reoccurrence of this fault, avoid operating the engine for extensive periods in low idle or low load conditions.
Result : The engine has not operated for too long at low speed or low load.
Proceed to Test Step 2.
2. Check for a Leaking DEF Injector
A. Perform the DEF dosing system accuracy test. Refer to Systems Operation, Testing and Adjusting, "Aftertreatment SCR System Dosing Test" for the correct procedure.
DEF Dosing
Result: The quantity of DEF collected is not within the acceptable range.
Repair: Replace the DEF injector. Refer to Disassembly and Assembly, "DEF Injector and Mounting - Remove and Install"
Result: The quantity of DEF collected is within the expected range.
Proceed to Test Step 3.
3. Exhaust System Insulation
A. Check the insulation on the exhaust system for damage, degradation, or missing insulation.
Exhaust System Insulation
Result : The exhaust system insulation is missing, damaged, or degraded.
Repair: Repair or replace the exhaust system insulation.
Result : The exhaust system insulation is OK.
Proceed to Test Step 4.
4. SCR Inlet Temperature
A. Start the engine. Operate the engine at full load and operating speed.
B. Use the electronic service tool to monitor the SCR inlet temperature.
250° C (482° F)
Result: The SCR inlet temperature does not rise above 250° C (482° F).
Repair: Refer to Troubleshooting, "SCR Catalyst Has Incorrect Inlet Temperature".
Result: The SCR inlet temperature rises above 250° C (482° F).
Contact the Dealer Solutions Network (DSN).