34516 Mercruiser NUT, VALUE ROCKER ARM STUD

Introduction
The problem identified below does not have a permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
There have been instances of faults codes with the DEF Pump, which can lead to an engine derate condition. Affected part numbers for the DEF pumps are:
473-2749 Diesel Exhaust Fluid Pump Gp
473-2750 Diesel Exhaust Fluid Pump Gp
466-8285 Diesel Exhaust Fluid Pump Gp
466-8286 Diesel Exhaust Fluid Pump GpThe codes can be:
Table 1
Event Codes
J1939 Code CDL Code Description
4334-16 E930 (2) Aftertreatment #1 DEF #1 Pressure (absolute) : High - moderate severity (2)
4334-18 E931 (2) Aftertreatment #1 SCR Dosing Re-agent Absolute Pressure : Low - moderate severity (2)
4374-5 E3118 (6) Aftertreatment #1 Diesel Exhaust Fluid Pump Motor Speed : Current Below Normal
5392-31 E1370 (2) Aftertreatment Diesel Exhaust Fluid Dosing Unit Loss of Prime Caterpillar is investigating the root cause of these issues. To support the investigation, Caterpillar is requesting that the following steps are completed, documented, and recorded in SIMSi.Solution
Before starting any troubleshooting, download a Product Status Report (PSR) from the affected engine. Ensure that the PDF and the XML version of the PSR are downloaded, with the Histogram option selected in the Download List.Follow the appropriate troubleshooting steps for the displayed fault codes. Document the results of the troubleshooting tests in the relevant tables. Refer to Tables 2, 3, and 4.If Troubleshoot requests the Pump and Electronics Unit (PEU) to be replaced, conduct the following inspection before removal of the PEU.
Check the DEF for contamination, if the relevant troubleshooting procedure has not instructed you to do so. Refer to "System Operation Testing and Adjusting", Diesel Exhaust Fluid Quality - Test for the correct procedure.
Inspect the DEF tank cap, DEF header filter, DEF pump filter for any visible obstruction
Illustration 1 g06152768
(1) DEF line in
(2) DEF line out
(3) DEF line out let connection
(4) DEF line inlet connection
(5) Injector DEF line
Inspect and photograph both ends of the DEF fluid lines. If the ends of the lines are damaged or swollen, replace the DEF lines. Refer to "Disassembly and Assembly", Diesel Exhaust Fluid Lines - Remove and Install.At the end of the service take another PSR irrespective of outcome. Ensure that the PDF and the XML version of the PSR are downloaded, with the Histogram option selected in the Download List.If the troubleshooting steps have required a component to be changed, hold all replaced components for 30 days for a possible Parts Return Request (PRR). Make sure to include the closed work order paperwork.In every instance submit a SIMSi report, complete with TIB number M0079072, CPI number 359775 and submit through the CPI feedback tool within the SIMSi.
Detailed description of symptom experienced and under what conditions issue occurred
Product Status Report (PSR) before and after troubleshooting. Ensure that the PDF and the XML version of the PSR are downloaded, with the Histogram option selected in the Download List.
Completed Troubleshooting steps tables. Refer to Tables 2, 3, and 4.
Details of DEF tank cap, DEF header filter, DEF pump filter, visual inspection
Photos of DEF fluid lines
Details of parts replaced
Machine location (city, state, country)
Machine manufacturer and sales model
Regeneration summary report from the engine ECM
Warranty report from the ECM
Engine operating hours
Table 2
DEF Pressure is Low
Step Troubleshooting Test Steps Completed (Yes/No) Results /Comments
1 Check latest available software installed
2 Check DEF Tank Filling Procedure
3 Check the DEF for Contamination. Refer to "System Operation Testing and Adjusting", Diesel Exhaust Fluid Quality - Test
4 Check the DEF Level
5 Check the Electrical Connection at the DEF Tank Header
6 Inspect the Lines for Leaks
7 Check the Suction Line Restrictions
8 Replace the DEF Pump Filter
9 Clean the DEF Tank filler screen
10 Flush the DEF Tank and Replace the DEF Tank Header Filter
11 Check for a Leaking DEF Injector
12 Perform an Aftertreatment System Functional Test
Table 3
DEF Pressure is High
Step Troubleshooting Test Steps Completed (Yes/No) Results /Comments
1 Check latest available software installed
2 Check DEF Lines for Restrictions
3 Check for a Restriction in the DEF Pump
4 Check for a Restriction in the DEF Injector
5 Install a Replacement DEF Pump Filter
6 Perform an Aftertreatment System Functional Test
Table 4
DEF Pump Test