18778001 Mercury GROMMET

Table 1
Diagnostic Trouble Codes
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
651-5 1-5 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
If equipped, 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 2-5 Engine Injector Cylinder #02 : Current Below Normal
653-5 3-5 Engine Injector Cylinder #03 : Current Below Normal
654-5 4-5 Engine Injector Cylinder #04 : Current Below Normal
655-5 (C7.1 only) 5-5 Engine Injector Cylinder #05 : Current Below Normal
656-5 (C7.1 only) 6-5 Engine Injector Cylinder #06 : Current Below Normal
651-6 1-6 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
If equipped, 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 2-6 Engine Injector Cylinder #02 : Current Above Normal
653-6 3-6 Engine Injector Cylinder #03 : Current Above Normal
654-6 4-6 Engine Injector Cylinder #04 : Current Above Normal
655-6 (C7.1 only) 5-6 Engine Injector Cylinder #05 : Current Above Normal
656-6 (C7.1 only) 6-6 Engine Injector Cylinder #06 : Current Above Normal
Follow the troubleshooting procedure 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 circuit, a diagnostic code is generated. The ECM continues to try to fire the injector. If a short circuit is detected, a diagnostic code is generated. The ECM will periodically try to fire the injector. If the short circuit remains, this sequence of events will be repeated until the fault is corrected."Injector Solenoid Test"Use the "Injector Solenoid Test"to diagnose an open or short circuit diagnostic code while the engine is not running. The "Injector Solenoid Test" will send a signal to each solenoid. The electronic service tool will indicate the status of the solenoid as "OK", "Open", or "Short".
Illustration 1 g03525259
Schematic of the circuit for the injector solenoids on C4.4 engines
Illustration 2 g03371518
Schematic of the circuit for the injector solenoids on C7.1 engines
Illustration 3 g03525276
View of the pin locations on the P2 connector for the injector solenoids on C4.4 engines
(35) Return (cylinder 1)
(7) Return (cylinder 2)
(8) Return (cylinder 3)
(34) Return (cylinder 4)
(57) Supply (cylinder 1)
(63) Supply (cylinder 2)
(64) Supply (cylinder 3)
(58) Supply (cylinder 4)
Illustration 4 g03371523
View of the pin locations on the P2 connector for the injector solenoids on C7.1 engines
(6) Return (cylinder 6)
(7) Return (cylinder 5)
(8) Return (cylinder 4)
(33) Return (cylinder 3)
(34) Return (cylinder 2)
(35) Return (cylinder 1)
(57) Supply (cylinder 1)
(58) Supply (cylinder 2)
(59) Supply (cylinder 3)
(62) Supply (cylinder 6)
(63) Supply (cylinder 5)
(64) Supply (cylinder 4)
Illustration 5 g01951833
Typical example of the harness connector for the fuel injector solenoids