COVER ASSEM. 7G3739 - Caterpillar

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Table 3
Troubleshooting Test Steps Values Results
1. Check for Logged Codes or Active Codes
A. Establish communication between Cat ET and the engine ECM. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Determine if the -5 or -6 code is active or logged.
Codes
Results: A -5 code or a -6 code is logged or active.
Proceed to Test Step 3.
Result: A code is not logged or active.
Proceed to Test Step 2.
2. Perform the "Cylinder Cutout Test"
A. Start the engine. Allow the engine to warm up to normal operating temperature .
B. Perform the "Cylinder Cutout Test". Check for a noticeable change in fuel usage.
Fuel usage
Results: There is a noticeable change in fuel usage. The injectors are firing on all cylinders at this time.
Proceed to Test Step 3.
Results: There is not a noticeable change in fuel usage.
Verify that the valve lash for the suspect cylinder is OK then replace the suspect injector.
Verify that the repair eliminated the problem.
3. Check the Harness between the ECM and the Injector Connectors for an Open Circuit
A. A. Turn the main disconnect switch to the OFF position.
A strong electrical shock hazard is present if the keyswitch is not turned off.
B. Disconnect the harness connectors for the affected cylinder at the cylinder head.
C. Fabricate a jumper wire that is long enough to create a test circuit across the harness connector at the cylinder head. Crimp connector pins to each end of the jumper wire.
D. Connect the jumper wire between terminal locations 1 (supply) and 2 (return). This test will effectively create a short circuit for the cylinder.
E. Restore the electrical power to the ECM.
F. Perform the "Injector Solenoid Test" at least two times.
Harness
Results: Cat ET displays "Short" for the cylinder with the jumper wire. The harness is OK. Remove the jumper wire. Connect the harness connectors.
Proceed to Test Step 4.
Results: Cat ET displays "Open" for the cylinder with the jumper wire. The ECM did not detect the jumper wire. There is an open circuit in the wiring harness.
Repair Correct the problem with the harness. Replace parts, if necessary. Start the engine.
Verify that the repair eliminated the problem.
4. Check the Harness between the ECM and the Injector Connectors for a Short Circuit
A. Turn the main disconnect switch to the