LINK 1342574 - Caterpillar

Table 1
Diagnostic Trouble Codes
J1939 Code CDL Code Code Description Comments
4360-16 E946 (2) Aftertreatment #1 SCR Catalyst Intake Gas Temperature : High - moderate severity (2) The aftertreatment SCR catalyst intake gas temperature sensor has detected that the SCR intake temperature is above the normal operating range.
4360-17 E947 (1) Aftertreatment #1 SCR Catalyst Intake Gas Temperature : Low - least severe (1) The aftertreatment SCR catalyst intake gas temperature sensor has detected that the SCR intake temperature is below the normal operating range.
4360-18 E947 (2) Aftertreatment #1 SCR Catalyst Intake Gas Temperature : Low – moderate severity (2) The aftertreatment SCR catalyst intake gas temperature sensor has detected that the SCR intake temperature is far below the normal operating range.
Illustration 1 g03273938
(1) Turbocharger
(2) DPF
(3) SCR inlet
(4) SCR outlet The temperature of the exhaust gas is checked by the SCR inlet temperature sensor (5) at the inlet of the SCR canister (3). This input is used to ensure a proper reaction with the SCR catalyst and to properly dose DEF into the exhaust stream.
Illustration 2 g03273939
(5) SCR inlet temperature sensor
Table 2
Troubleshooting Test Steps Values Results
1. Determine the diagnostic code.
A. Connect Cat® ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Determine if a diagnostic trouble code is present.
Diagnostic trouble code
Result : A 4360-16 or E946 (2) code with an ETI of 1 or 2 is active or logged.
Proceed to Test Step 2.
Result : A 4360-17, E947 (1), 4360-18 or E947 (2) code is logged or active.
Proceed to Test Step 2.
2. Check the operation of the SCR catalyst inlet temperature sensor.
Note : Only perform this step on a cold engine.
A. Remove the SCR catalyst inlet temperature sensor and allow the sensor to rest in ambient air for 2 minutes.
B. Connect to the engine ECM by using Cat ET.
C. Monitor the value of the SCR catalyst inlet temperature sensor on Cat ET.
Sensor
Result : The value of the SCR catalyst inlet temperature sensor is within 9° C (15° F) of ambient temperature.
Repair : Reinstall the sensor. torque the sensor to the proper specification.
For a 4360-16 or E946 (2) code proceed to Test Step 4.
For a 4360-17, E947 (1), 4360-18 or E947 (2) code proceed to Test Step 3.
Result : The value of the SCR catalyst inlet temperature sensor is not within 9° C (15° F) of ambient temperature.
Repair : Replace the SCR catalyst inlet temperature sensor. Refer to the Disassembly and Assembly manual for more information.
Proceed to Test Step 5.
3. Check for exhaust leaks.
A. Start the engine.
B. Check the exhaust system for proper installation.
C. Check for proper installation of the exhaust system insulation.
D. Inspect the exhaust system between the DPF and the SCR for signs of an exhaust leak.
E. Inspect the SCR inlet temperature sensor to ensure proper installation in the sensor port.
Exhaust leaks
Result : There were exhaust leaks found.
Repair : Repair or replace the component that is causing an exhaust leak.
Proceed to Test Step 5.
4. Check the Diesel Exhaust Fluid (DEF) quality.
A. Measure the DEF quality. Refer