369-66021-1 Tohatsu O-RING, 2.5 - 4.9

Table 1
Diagnostic Codes for NRS Exhaust Gas Temperature Is High
CDL Code Code Description Comments
E1092(2) High Engine Exhaust Gas Recirculation Temperature The temperature of the exhaust temperature for the NOX Reduction System (NRS) has exceeded the threshold for a set amount of time. Note: Exhaust Gas Recirculation (EGR) is a 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. The diagnostic codes will reflect the EGR nomenclature.
Illustration 1 g02128173
Location of the NRS components (top side engine view)
(1) NRS valve
(2) NRS temperature sensor
Illustration 2 g02128654
Location of the components for the NRS cooler that is on the left side of the engine (left side engine view)
(3) Vent line
(4) Coolant inlet tube
(5) Piping for the exhaust inlet
(6) NRS cooler
(7) Coolant outlet tube
(8) Exhaust outlet piping
(7) Coolant outlet Test Step 1. Check for Active Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector. Establish communication between Cat ET and the engine ECM. Refer to Troubleshooting, "Electronic Service Tools" for details.
Download the "Product Summary Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Note: Wait for at least 30 seconds in order for diagnostic codes to become active.
Determine if an associated code is active or logged. Table 2 lists associated diagnostic codes.
Table 2
Associated Codes
CDL Code WCI
E361 (1), (2), or (3)
E1095 (2) Expected Result:No associated codes are active at this time.Results:
OK - No associated codes are active at this time. The 1092(2) remains active. Proceed to test step 2.
Active E361 Code - The E361 code is active at this time.Repair: The associated code may be indicating an overheating condition for the engine. Refer to Troubleshooting, "Diagnostic Trouble Codes" in order to troubleshoot the associated diagnostic code.STOP
Active E1092 and E1095 Codes - The E1092 code is accompanied by the E1095 code. There may be a problem with the NRS cooler. Proceed to Test Step 3.Test Step 2. Use Cat ET to perform an "EGR Service Test"
Clear all logged codes. Use Cat ET to perform an "EGR Service Test".
Select the "Diagnostics" drop-down menu.
Select the "Diagnostics Tests" from the menu.
Select the "EGR Service Test".
Once "EGR Service Test" is selected, follow the instructions on the display screen in order to run the test. Expected Result:The "EGR Service Test" is completed successfully.Results:
OK - The "EGR Service Test" is successful. There may be a problem with the NRS cooler. Proceed to Test Step 3.
Not OK - The "EGR Service Test" is not successful due to a E1092(2) code that is active.Repair: The NRS system appears to be overheating. Check the condition of the vent lines for the coolers to the inlet into the engine block. If necessary, replace the vent lines from the cooler to the engine block.Remove the exhaust lines from the inlet and the outlet of the coolers. Inspect the internal passage of the coolers for indications of coolant leakage. If evidence of coolant leakage is found, replace the coolers.Clear all logged codes. Use Cat ET to perform an "EGR Service Test" in order to verify that the problem is resolved.STOPTest Step 3. Perform a Leak Test on the NRS Coolers
Remove the NRS coolers from the engine. Refer to Disassembly and Assembly for more information.
Perform a leak test on each of the coolers. Refer to the Testing and Adjusting manual for the proper procedure. Expected Result:The NRS coolers are not leaking.Results:
OK - The coolers are not leaking internally.Repair: Clean the coolers. Refer to the Testing and Adjusting manual for the proper procedure that is used to clean the NRS cooler.If the problem is not resolved, contact your Technical Communicator (TC) for further instructions.STOP
Not OK - The coolers are leaking internally.Repair: Replace the coolers. Replace the exhaust bellows at the inlet and the outlet of the cooler.Clear all diagnostic codes. Use Cat ET to perform an "EGR Service Test" in order to verify that the problem is resolved. Return the unit to service.STOP