C2.2 Engines For Caterpillar Built Machines Caterpillar

Injector Solenoid - Test

Usage:

239D BL9

This procedure covers the following diagnostic codes:

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Table 1
Diagnostic Trouble Codes for Injector Solenoid
J1939 Code	Code Description	Comments
651-3	Engine Injector Cylinder #01 : Voltage Above 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) 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.
652-3	Engine Injector Cylinder #02 : Voltage Above Normal
653-3	Engine Injector Cylinder #03 : Voltage Above Normal
654-3	Engine Injector Cylinder #04 : Voltage Above Normal (4 cylinder engines only)
2797-3	Engine Injector Group 1 : Voltage Above Normal	3 Cylinder Engines: These diagnostic codes indicate a fault in the common circuit in the ECM that supplies power to electronic unit injector 1 and 3. 4 Cylinder Engines: These diagnostic codes indicate a fault in the common circuit in the ECM that supplies power to electronic unit injectors 1 and 4. Contact the Dealer Solutions Network (DSN).
2797-4	Engine Injector Group 1 : Voltage Below Normal
2797-5	Engine Injector Group 1 : Current Below Normal
2798-3	Engine Injector Group 2 : Voltage Above Normal	3 Cylinder Engines: These diagnostic codes indicate a fault in the circuit in the ECM that supplies power to electronic unit injector 2. 4 Cylinder Engines: These diagnostic codes indicate a fault in the common circuit in the ECM that supplies power to electronic unit injectors 2 and 3. Contact the Dealer Solutions Network (DSN).
2798-4	Engine Injector Group 2 : Voltage Below Normal
2798-5	Engine Injector Group 2 : Current Below Normal
Follow the troubleshooting procedure to identify the root cause of the fault.

Perform this procedure under conditions that are identical to the conditions that exist when the fault occurs. Typically, electronic unit injector solenoid faults occur when the engine is warmed up and/or when the engine is under vibration (heavy loads).

The engine has 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 electronic unit injector body.

An electrical fault can prevent the electronic unit injector from operating. An open circuit in the ECM that is unique to one electronic unit injector will prevent that electronic unit injector from operating. An open circuit in common wiring within the ECM can prevent the two electronic unit injectors that share that common wiring from operating.

If an open circuit is detected in the solenoid circuit, a diagnostic code is generated. The ECM continues to try to fire the electronic unit injector.

"Injector Solenoid Test"

Use the "Injector Solenoid Test"to diagnose an open circuit diagnostic code with 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" or "Open".

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Illustration 1	g06100345
Schematic of the 3 cylinder engine circuit for the electronic unit injector solenoids

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Illustration 2	g06005332
Schematic of the 4 cylinder engine circuit for the electronic unit injector solenoids

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Illustration 3	g06087856
View of the pin locations on the 3 cylinder engine P2 connector for the electronic unit injector solenoids (49) Supply (cylinder 1) (74) Return (cylinder 1) (25) Supply (cylinder 2) (26) Return (cylinder 2) (73) Supply (cylinder 3) (51) Return (cylinder 3)

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Illustration 4	g06036221
View of the pin locations on the 4 cylinder engine P2 connector for the electronic unit injector solenoids (49) Supply (cylinder 1) (74) Return (cylinder 1) (1) Supply (cylinder 2) (3) Return (cylinder 2) (25) Supply (cylinder 3) (26) Return (cylinder 3) (73) Supply (cylinder 4) (51) Return (cylinder 4)

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Illustration 5	g03831808
Electronic unit injector

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Electrical Shock Hazard. The electronic unit injectors use DC voltage. The ECM sends this voltage to the electronic unit injectors. Do not come in contact with the harness connector for the electronic unit injectors while the engine is operating. Failure to follow this instruction could result in personal injury or death.

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Table 2
Troubleshooting Test Steps	Values	Results
1. Inspect Electrical Connectors and Wiring A. Turn the keyswitch to the OFF position. A strong electrical shock hazard is present if the keyswitch is not turned OFF. B. Thoroughly inspect the connectors on the electronic unit injectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with electronic unit injector solenoids. D. Check the harness and wiring for abrasion and for pinch points from the electronic unit injectors to the ECM.	Loose connection or damaged wire	Result: There is a fault in a connector or the wiring. Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all the seals are properly in place and ensure that the connectors are correctly coupled. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points. Proceed to Test Step 2.
2. Check for Diagnostic Codes A. Turn the keyswitch to the ON position. B. Connect the electronic service tool to the diagnostic connector. C. Check for active or logged codes that are associated with the electronic unit injectors. D. Turn the keyswitch to the OFF position.	Diagnostic codes	Result: No diagnostic codes are active or logged. Return the unit to service. Result: A 65X-3 code is active or logged. Note: The "X" in the diagnostic code indicates which electronic unit injector is suspect. Proceed to Test Step 3.
3. Check the Electronic Unit Injector Solenoid A. Turn the keyswitch to the OFF position. B. Disconnect the electrical connector from the suspect electronic unit injector. C. Measure the resistance between pins 1 and 2 on the electronic unit injector.	Approximately 0.47 Ohms	Result: The resistance measurement is not approximately 0.47 Ohms. Repair: Install a replacement electronic unit injector. Refer to Disassembly and Assembly, "Fuel Injector - Remove and Install". Result: The resistance measurement is approximately 0.47 Ohms. Proceed to Test Step 4.
4. Check the Harness for an Open Circuit A. Turn the keyswitch to the OFF position. A strong electrical shock hazard is present if the keyswitch is not turned OFF. B. Disconnect the connector from the suspect electronic unit injector. C. Disconnect the P2 connector from the engine ECM. D. Check the resistance between pin 1 on the electronic unit injector and the associated pin on the P2 connector. D. Check the resistance between pin 2 on the electronic unit injector and the associated pin on the P2 connector.	Open Circuit	Result: One of the resistance measurements is more than 2.0 Ohms. Repair: Repair the wiring harness or replace the wiring harness. Result: The resistance measurements are less than 2.0 Ohms. Contact the Dealer Solutions Network (DSN).