SEAT 9T1636 - Caterpillar

This procedure covers the following diagnostic codes:
Table 1
Diagnostic Trouble Codes for Injector Solenoid    
J1939 Code    Code Description    Comments    
651-5     Engine Injector Cylinder #01 : Current Below Normal     These diagnostic codes indicate an open circuit (low current) in either the solenoid or the wiring for the electronic unit injector.
The Electronic Control Module (ECM) detects the following conditions:
A low current condition (open circuit) for each of five consecutive attempts to operate
Battery voltage above 9 VDC for 2 seconds
The warning light will come on. The ECM will log the diagnostic code.
The engine will have low power and/or rough running.
When an "Cylinder Cutout Test" is performed, a faulty electronic unit injector will indicate a low reading in comparison with the other electronic unit injectors.
The ECM will continue to attempt to operate the electronic unit injector after the diagnostic code has been logged. An open circuit will prevent the operation of the electronic unit injector.    
652-5     Engine Injector Cylinder #02 : Current Below Normal    
653-5     Engine Injector Cylinder #03 : Current Below Normal    
654-5     Engine Injector Cylinder #04 : Current Below Normal    
651-6     Engine Injector Cylinder #01 : Current Above Normal     These diagnostic codes indicate a short circuit (high current) in either the solenoid or the wiring for the electronic unit injector.
The ECM detects the following conditions:
A high current condition (short circuit) for each of five consecutive attempts to operate
Battery voltage above 9 VDC for 2 seconds
The warning light will come on. The ECM will log the diagnostic code.
The engine will have low power and/or rough running.
The ECM will continue to attempt to operate the electronic unit injector after the diagnostic code has been logged. A short circuit will prevent the operation of the electronic unit injector.    
652-6     Engine Injector Cylinder #02 : Current Above Normal    
653-6     Engine Injector Cylinder #03 : Current Above Normal    
654-6     Engine Injector Cylinder #04 : Current Above Normal    
Follow the troubleshooting procedure in order to identify the root cause of the fault.    An electrical fault can prevent the electronic unit injector from operating. An open or short circuit in the ECM that is unique to one electronic unit injector will prevent that electronic unit injector from operating. An open or short circuit in common wiring within the ECM can prevent the two electronic unit injectors that share that common wiring from operating.Perform this procedure under conditions that are identical to the conditions that exist when the fault occurs. Typically, faults with the injector solenoid occur when the engine is warmed up and/or when the engine is under vibration (heavy loads).These engines have Electronic Unit Injectors (EUI). The ECM sends a pulse to each injector solenoid. The pulse is sent at the correct time and at the correct duration for a given engine load and speed. The solenoid is mounted on top of the fuel injector body.If an open circuit is detected in the solenoid