CONNECTOR 6V9872 - Caterpillar

Note: If the fault is intermittent and the fault cannot be duplicated, refer to Troubleshooting, "Power Is Intermittently Low or Power Cutout Is Intermittent".Note: If the fault only occurs under certain conditions, test the engine under those conditions. Examples of certain conditions are high rpm, full load, and engine operating temperature. Troubleshooting the symptoms under other conditions can give misleading results.Probable Causes
Diagnostic codes
Fuel supply
High-pressure fuel pump SCV
High-pressure fuel pump
Low compression (cylinder pressure)
Electronic unit injectors
Individual malfunctioning cylinderRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 1
Troubleshooting Test Steps    Values    Results    
1. Diagnostic Codes
A. Establish communication between the electronic service tool and the Electronic Control Module (ECM). Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Download the "Warranty Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
   
Codes
   
Result: There are active codes.
Troubleshoot any active codes before continuing with this procedure.
Result: There are no active codes.
Proceed to Test Step 2.
   
2. Fuel Supply
A. Visually check the fuel tank for fuel. The fuel gauge may be faulty.
B. Ensure that the fuel supply valve (if equipped) is in the full OPEN position.
C. Check the primary filter/water separator for water in the fuel.
D. Check for fuel supply lines that are restricted.
E. Check for air in the fuel system. Refer to Systems Operation, Testing, and Adjusting, "Air in Fuel - Test".
F. Obtain a fuel analysis in order to confirm that the correct fuel is being used. Refer to Systems Operation/Testing and Adjusting, "Fuel Quality - Test" for the correct procedure.
   
Fuel supply
   
Result: There is air in the fuel system.
Prime the fuel system. Refer to Systems Operation, Testing, and Adjusting, "Fuel System - Prime".
Result: The fuel quality is not OK.
Replace the fuel. Replace the primary and secondary fuel filters. Verify that the repair eliminated the fault.
Result: The fuel quality is OK.
Proceed to Test Step 3.
   
Illustration 1 g03582241
Transfer Pump Inlet Regulator (TPIR) components (1) Fuel return to the secondary fuel filter (2) Transfer Pump Inlet Regulator (TPIR) (3) TPIR return port
Illustration 2 g02485896
Minimum TPIR flow rate with a 12 VDC system
Illustration 3 g02485897
Minimum TPIR flow rate with a 24 VDC system
Table 2
Troubleshooting Test Steps    Values    Results    
3. Transfer Pump Inlet Regulator (TPIR) Flow Test
Refer to Illustration 1.
A. Disconnect the TPIR return line from the drain port on the TPIR. Install a suitable blanking cap on the open port in the TPIR return line.
B. Connect a temporary drain line to the drain port on the TPIR.
C. Place the end of the temporary drain line into a suitable calibrated container.
D. With the isolator switch in the ON position but the engine not running, use a suitable multimeter to measure the input voltage to the EFLP. Record the reading.
E. With the isolator switch in the ON position but the engine not running, measure the fuel flow from the temporary drain line.
F. For a 12 VDC system, refer to Illustration 2 for the minimum acceptable flow rate.
G. For a 24 VDC system, refer