SEAL 1P4879 - Caterpillar

System Operation Description:This procedure covers the following diagnostic codes:
Table 1
Diagnostic Trouble Codes for the Injector Electrical Circuits
J1939 Codes Description Notes
651-5 Engine Injector Cylinder #01 current below normal These codes relate to the electrical circuit that includes injector terminals 1 and 3.
651-6 Engine Injector Cylinder #01 current above normal
652-5 Engine Injector Cylinder #02 current below normal
652-6 Engine Injector Cylinder #02 current above normal
653-5 Engine Injector Cylinder #03 current below normal
653-6 Engine Injector Cylinder #03 current above normal
654-5 Engine Injector Cylinder #04 current below normal
654-6 Engine Injector Cylinder #04 current above normal
655-5 Engine Injector Cylinder #05 current below normal
655-6 Engine Injector Cylinder #05 current above normal
656-5 Engine Injector Cylinder #06 current below normal
656-6 Engine Injector Cylinder #06 current above normal
3659-5 Engine Injector Cylinder #1 Actuator 2 current below normal These codes relate to the electrical circuit that includes injector terminals 2 and 4.
3659-6 Engine Injector Cylinder #1 Actuator 2 current above normal
3660-5 Engine Injector Cylinder #2 Actuator 2 current below normal
3660-6 Engine Injector Cylinder #2 Actuator 2 current above normal
3661-5 Engine Injector Cylinder #3 Actuator 2 current below normal
3661-6 Engine Injector Cylinder #3 Actuator 2 current above normal
3662-5 Engine Injector Cylinder #4 Actuator 2 current below normal
3662-6 Engine Injector Cylinder #4 Actuator 2 current above normal
3663-5 Engine Injector Cylinder #5 Actuator 2 current below normal
3663-6 Engine Injector Cylinder #5 Actuator 2 current above normal
3664-5 Engine Injector Cylinder #6 Actuator 2 current below normal
3664-6 Engine Injector Cylinder #6 Actuator 2 current above normal Background InformationThese engines have Electronic Unit Injectors (EUI) that are electronically controlled. Each injector contains two solenoids. The Engine Control Module (ECM) sends 105 V pulses to each injector solenoid. The pulses are sent at the proper time and at the correct duration for a given engine load and speed.The ECM monitors the current flow through the circuit for each solenoid. If low current flow is detected, a diagnostic code is activated. The ECM continues to try to fire the injector.If high current flow is detected, a diagnostic code is activated. The ECM will disable the solenoid circuit in order to prevent damage from the high current flow. However, the ECM will periodically try to fire the injector. If the short circuit remains, this sequence of events will be repeated until the problem is corrected.Ensure that the fuel system is not restricted. A restricted fuel supply to the injectors will cause the injector solenoids to overheat and possibly fail. A sufficient fuel supply to the injector solenoids is necessary to cool the solenoids during operation.Typically, problems with an injector solenoid occur when the engine is warmed up and/or when the engine is under vibration (heavy loads). Perform this procedure when the engine is at normal operating temperature. Pay careful attention to the condition of the wiring and the connectors as you perform this procedure. The wiring and/or the connectors may have problems that only occur during vibration.Diagnostic Tests on the Caterpillar Electronic Technician (ET)Cat ET includes the following test that aids in troubleshooting injector solenoids:Injector Solenoid Test -