YOKE-STUB 8D7718 - Caterpillar

System Operation Description:This procedure covers the following diagnostic trouble codes. Access the engine monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these codes. Refer to Troubleshooting, "Engine Monitoring Parameters" for information about engine events.
Table 1
Engine Event
J1939 Code and Description Conditions that Generate the Code System Response
412-15 Engine Exhaust Gas Recirculation Temperature : High - least severe (1) The temperature of the exhaust temperature for the NOX Reduction System (NRS) has exceeded the threshold for a set amount of time. The code is logged
412-16 Engine Exhaust Gas Recirculation Temperature : High - moderate severity (2) 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 the Society of Automotive Engineers (SAE). The diagnostic codes use the EGR nomenclature.
Illustration 1 g02214793
Location of the NRS components (typical top side engine view)
(1) NRS valve
(2) NRS temperature sensor
Illustration 2 g02214737
Location of the components for the NRS cooler that is on the left side of the engine (typical 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 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
J1939 Code Description
110-0 Engine Coolant Temperature : High - most severe (3)
110-15 Engine Coolant Temperature : High - least severe (1)
110-16 Engine Coolant Temperature : High - moderate severity (2)
2659-17 Engine Exhaust Gas Recirculation (EGR) Mass Flow Rate : Low - least severe (1) Expected Result:No associated codes are active at this time.Results:
OK - No associated codes are active at this time. The 412 code remains active. Proceed to test step 2.
Active 110 Code - There is a 110 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 412 Code and 2659 Code - The 412 code is accompanied by a 2659 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