C18 Industrial Engine Caterpillar

Injector Solenoid - Test

Usage:

C18 ZPS

This procedure covers the following diagnostic trouble codes:

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Table 1
Diagnostic Codes Table
CDL Code	J1939 Code	Code Description (code descriptions may vary)	Comments
1-5	651-5	Cylinder #1 Injector : Current Below Normal	These codes relate to the electrical circuit that includes injector terminals 1 and 3.
1-6	651-6	Cylinder #1 Injector : Current Above Normal
2-5	652-5	Cylinder #2 Injector : Current Below Normal
2-6	652-6	Cylinder #2 Injector : Current Above Normal
3-5	653-5	Cylinder #3 Injector : Current Below Normal
3-6	653-6	Cylinder #3 Injector : Current Above Normal
4-5	654-5	Cylinder #4 Injector : Current Below Normal
4-6	654-6	Cylinder #4 Injector : Current Above Normal
5-5	655-5	Cylinder #5 Injector : Current Below Normal
5-6	655-6	Cylinder #5 Injector : Current Above Normal
6-5	656-6	Cylinder #6 Injector : Current Below Normal
6-6	656-6	Cylinder #6 Injector : Current Above Normal
2602-6	3659-5	Cylinder #1 Injector Actuator #2 : Current Above Normal	These codes relate to the electrical circuit that includes injector terminals 2 and 4.
2602-5	3659-6	Cylinder #1 Injector Actuator #2 : Current Below Normal
2604-6	3660-5	Cylinder #2 Injector Actuator #2 : Current Above Normal
2604-5	3660-6	Cylinder #2 Injector Actuator #2 : Current Below Normal
2606-6	3661-5	Cylinder #3 Injector Actuator #2 : Current Above Normal
2606-5	3661-6	Cylinder #3 Injector Actuator #2 : Current Below Normal
2608-6	3662-5	Cylinder #4 Injector Actuator #2 : Current Above Normal
2608-5	3662-6	Cylinder #4 Injector Actuator #2 : Current Below Normal
2610-6	3663-5	Cylinder #5 Injector Actuator #2 : Current Above Normal
2610-5	3663-6	Cylinder #5 Injector Actuator #2 : Current Below Normal
2612-6	3664-5	Cylinder #6 Injector Actuator #2 : Current Above Normal
2612-5	3664-6	Cylinder #6 Injector Actuator #2 : Current Below Normal

Background Information

These 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.

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 - The Injector Solenoid Test identifies an open circuit or a short circuit in the circuits for the injector solenoids. The test is performed while the engine is not running. The "Injector Solenoid Test" briefly activates each solenoid. A good solenoid will create an audible click when the solenoid is activated. Cat ET indicates the status of the solenoid as "OK","Open" or "Short".

Note: Refer to the following schematic. Two injector solenoids share a common supply wire. For this reason, an open circuit or a short circuit in a supply wire could cause diagnostic codes for two cylinders.

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Illustration 1	g01953821
Schematic for the injector solenoids

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Table 2
Troubleshooting Test Steps	Values	Results
1. Check for Logged Codes or Active Codes A. Establish communication between Cat ET and the ECM. Refer to Troubleshooting, "Electronic Service Tools", if necessary. B. Determine if a code is active or logged.	Logged or Active codes	Result: A code is logged or active. A -5 code or a -6 code is logged or active. Proceed to Test Step 2. Result: A code is not logged or active. There is not an electronic problem with the injectors at this time.
2. Inspect the Wiring Harness Between the ECM and the Valve Cover Base A. Turn the keyswitch to the OFF position. B. Thoroughly inspect the connectors. 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. Perform a pull test on each of the wires that are associated with injector solenoids. D. Check the allen head screw on the ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values. E. Check the harness and wiring for abrasions and for pinch points from the valve cover base to the ECM.	Damaged wiring or connectors	Result: The connectors and the wiring appear to be OK. The harness between the ECM and the connector does not have an open circuit. Proceed to Test Step 3. Result: There is a problem with the connectors and/or wiring. Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are coupled. Perform an injector solenoid test in order to verify that the problem has been resolved.
3. Check the Harness between the ECM and the Valve Cover Base 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. Remove electrical power from the engine ECM. C. Disconnect the connectors of the injector harness at the valve cover base. D. Fabricate a jumper wire long enough to create a short circuit on the different terminal locations at the connector of the injector harness. Crimp connector pins on both ends of the jumper wire. E. Insert one end of the jumper wire into the connector socket for the suspect injectors supply wire. Insert the other end of the jumper wire into the connector socket for the suspect injectors return wire. The jumper wire will bypass the injector solenoid. F..Restore electrical power to the engine ECM. G.Turn the keyswitch to the ON position. H. Perform the "Injector Solenoid Test" in Cat ET. I. Repeat this test for each suspect circuit. Stop the "Injector Solenoid Test" before handling the jumper wire. Restore the wiring to the original configuration.	Short circuit is detected	Result: Cat ET displays a -6 code for each circuit that was jumpered. The harness between the ECM and the connector does not have an open circuit. Proceed to Test Step 4. Result: Cat ET does not display a -6 code for the cylinder with the jumper wire. Repair the harness or replace the harness between the ECM and the valve cover base. Perform an injector solenoid test in order to verify that the problem is resolved.
4. Check the Harness between the ECM and the Valve Cover Base for a Short Circuit A. Turn the keyswitch to the OFF position. A strong electrical shock hazard is present if the keyswitch is not turned off. B. Remove electrical power from the engine ECM. C. Disconnect the connectors of the injector harness at the valve cover base. D. Restore electrical power to the engine ECM. E. Turn the keyswitch to the ON position. F. Perform the Injector Solenoid Test at least two times.	Open circuit detected	Result: All cylinders indicate a -5 code on Cat ET. The harness between the ECM and the connector does not have a short circuit. Proceed to Test Step 5. Result: One or more cylinders indicate a -6 code on Cat ET. Note the cylinders that indicate "Short". The problem is in the wiring to the ECM or the ECM is not operating properly. Repair the wiring or replace the wiring to the ECM. Perform an injector solenoid test in order to verify that the problem is resolved. If the problem still exists, proceed to Test Step 8.
5. Inspect the Wiring Harness Between the Valve Cover Base and the Injectors A. Turn the keyswitch to the OFF position. A strong electrical shock hazard is present if the keyswitch is not turned off. B. Remove electrical power from the engine ECM. C. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details. D. Perform a 45 N (10 lb) pull test on each of the wires that are associated with injector solenoids. E. Check the harness and wiring for abrasions and for pinch points from the valve cover base to the injectors.	Damaged wiring or connectors	Result: The connectors and the wiring appear to be OK. Proceed to Test Step 6. Result: There is a problem with the connectors and/or wiring. Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are coupled. Perform an injector solenoid test in order to verify that the problem is resolved.
6. Check the Injector Harness under the Valve Cover for a Short Circuit A. Turn the keyswitch to the OFF position. A strong electrical shock hazard is present if the keyswitch is not turned off. B. Remove electrical power from the engine ECM. C. Remove the valve cover in order to gain access to the suspect injector. D. Disconnect the harness connector from the suspect injector. E. Inspect the seal around each wire. Verify that the seal is sealing correctly. F. Pull on each wire in order to verify that the wire and the terminal are correctly installed. G. Restore power to the ECM. H. Turn the keyswitch ON. I. Activate the "Injector Solenoid Test". Allow the Injector Solenoid Test to continue until each solenoid is activated at least two times.	Open circuit detected	Result: Cat ET displays "Open" for the solenoid that is not connected. Proceed to Test Step 7. Result: Cat ET displays "Short" for the solenoid that is not connected. There is a problem with the injector harness under the valve cover. Repair the wiring and/or the connector, when possible. Replace parts, if necessary. Perform an injector solenoid test in order to verify that the problem is resolved.

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Illustration 2	g01322701
Harness connector for an injector

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Table 3
Code	Connection for the Jumper
1-5 or -6 through 6- 5 or -6	Terminal 1 and Terminal 3
2602-5 or -6 through 2612-5 or -6	Terminal 2 and Terminal 4

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Table 4
Troubleshooting Test Steps	Values	Results
7. Check the Injector Harness under the Valve Cover 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. Remove electrical power from the engine ECM. C. Determine the appropriate terminals for the solenoid with the code. Connect a jumper wire between the terminal for the supply and the terminal for the return. The jumper wire will replace the injector solenoid with a short circuit. D. Turn the keyswitch ON. E. Activate the "Injector Solenoid Test". Allow the Injector Solenoid Test to continue until each solenoid is activated at least two times.	Short circuit detected	Result: Cat ET displays "Short " for the connector that has the jumper wire. The wiring is OK. Proceed to Test Step 8. Result: Cat ET displays "Open " for the connector that has the jumper wire. The wiring has an open. Repair the harness or replace the harness under the valve cover. Perform an injector solenoid test in order to verify that the problem is resolved.
8. Check the ECM for Proper Operation A. Turn the keyswitch OFF. A strong electrical shock hazard is present if the keyswitch is not turned off. B. Disconnect the P2 connector. When the P2 connector is disconnected, numerous diagnostic codes will be generated when the keyswitch is turned ON. The codes are normal. Ignore the codes. Reset all active codes and clear all logged codes after you complete this Test Step. C. Turn the keyswitch ON. D. Activate the "Injector Solenoid Test". Allow the Injector Solenoid Test to continue until each solenoid is activated at least two times. E. Turn the keyswitch OFF. A strong electrical shock hazard is present if the keyswitch is not turned off. F. Use a jumper wire in order to create a short circuit on J2 between the terminals for the solenoids supply and the solenoids return. G. Turn the keyswitch ON. H. Activate the Injector Solenoid Test. Allow the Injector Solenoid Test to continue until each solenoid is activated at least two times.	Short and open detected	Result: Cat ET displays "Short" for the solenoid with the jumper wire. Cat ET will display "Open" when the P2 connector is not connected to the ECM. The problem is in the injector. Replace the injector. Perform an injector solenoid test in order to verify that the problem is resolved. Result: Cat ET does not display "Short" for the solenoid with the jumper wire. Cat ET does not display "Open" when P2 is not connected to the ECM. Perform the following procedure: 1. Temporarily connect a test ECM. Refer to Troubleshooting, "Test ECM Mode". 2. Activate the "Injector Solenoid Test". Allow the Injector Solenoid Test to continue until each solenoid is activated at least two times. If the test ECM fixes the problem, connect the suspect ECM. If the problem returns with the suspect ECM, replace the ECM. Verify that the problem is resolved.