INSERT 7D5895 - Caterpillar

The high-pressure fuel pump contains two "pressurizing assemblies". Each assembly contains a solenoid. The Engine Electronic Control Module (ECM) sends 105 v pulses to each solenoid. The pulses are sent at the proper time and for the correct duration for a given engine load and speed.The ECM monitors the current flow through the circuit for each solenoid. If the current flow is too high or too low, the ECM activates one of the following diagnostic codes:
Table 1
Diagnostic Trouble Codes    
J1939 Code    CDL Code    Code Description    Comments    
1347-5     1779-5     Fuel Rail #1 Pressure Valve Solenoid : Current Below Normal     The ECM detects signal voltage that is not in the acceptable range.
The code is logged.    
1347-6     1779-6     Fuel Rail #1 Pressure Valve Solenoid : Current Above Normal     The ECM detects signal voltage that is not in the acceptable range.
The code is logged.    
1348-5     1780-5     Fuel Rail #2 Pressure Valve Solenoid : Current Below Normal     The ECM detects signal voltage that is not in the acceptable range.
The code is logged.    
1348-6     1780-6     Fuel Rail #2 Pressure Valve Solenoid : Current Above Normal     The ECM detects signal voltage that is not in the acceptable range.
The code is logged.    Note: The automatic cylinder cutout test is disabled while any of these codes are active.Automatic Configuration of the Solenoid DriversThe connectors for the solenoids are interchangeable. The ECM determines the connector that is connected to each solenoid during each engine start cycle. For this reason, either pump solenoid can be driven by either ECM driver.
Illustration 1 g03343251
Illustration 2 g01959043
Typical left side view
Illustration 3 g01959046
Harness connectors for the solenoidsComplete the procedure in the order in which the steps are listed.
Table 2
Troubleshooting Test Steps    Values    Results    
1. Determine the Diagnostic Code
A. Establish communication between Cat® Electronic Technician (ET) and the applicable 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.
C. Look for an active or logged -5 code or -6 code.
   
Diagnostic Trouble Codes    
Result: There is an active or there is a logged -5 code
Proceed to Test Step 2.
Result: There is an active or there is a logged -6 code.
Proceed to Test Step 3.
   
Illustration 4 g03343300
Table 3
Troubleshooting Test Steps    Values    Results    
2. Check the Wiring for an Open Circuit
A. Turn the keyswitch to the OFF position.
B. Verify that the harness connector is free of debris, free of corrosion and securely connected.
C. Disconnect both solenoids from the harness.
D. Connect a jumper wire between terminals 1 and 2 of the harness connector for each coil. Each coil is replaced with a short circuit.
E. Turn the keyswitch to the ON position. Do not start the engine.
F. Connect to Cat ET. Select the Diagnostics tab and perform the "Fuel Rail Pump Solenoid Test".
   
Short Circuit    
Result: The test results indicate "Not OK