REDUCER AS-GEAR 7X8557 - Caterpillar

This diagnostic code is designed to indicate an open circuit (low current) in either the solenoid or the wiring for the electronic unit injector for No. 4 cylinder.The Electronic Control Module (ECM) detects the following condition:
A low current condition (open circuit) for each of five consecutive attempts to operate
Battery voltage is higher than 9 Volts DC for 2 seconds.System Response:A warning will appear on the display on the control panel. The ECM will log the diagnostic code.Possible Performance Effect:The engine will have low power and/or rough running.Troubleshooting:When an injector cutout test is performed, a faulty electronic unit injector will indicate a low reading in comparison with the other electronic unit injectors.An electrical fault can prevent the electronic unit injector from operating. An open circuit in the wiring that is unique to the electronic unit injector will prevent that individual electronic unit injector from operating. An open circuit in common wiring within the ECM can prevent the three electronic unit injectors that share that common wiring from operating.The ECM will continue to attempt to operate the electronic unit injector after the diagnostic code has been logged but an open circuit will prevent the operation of the electronic unit injector.Test Step 1. Perform the following diagnostic procedure: "Injector Solenoid Circuit - Test"Results:
OK - STOP