Injector Solenoid Circuit - Test. Use this procedure for the following conditions. Inspect the Electrical Connectors and the Wiring, страница 5

6. Perform the "Injector Solenoid Test" at least two times.

7. Repeat this test for each suspect circuit. Stop the "Injector Solenoid Test" before handling the jumper wire.

Restore the wiring to the original configuration.

Expected Result:

Cat ET displays "Short" for each circuits that was jumpered.

Results:

• OK - Cat ET displays "Short" for each circuit that was jumpered. The harness between the ECM and the P300 connector does not have an open circuit. Proceed to Test Step 7.
• Not OK - Cat ET displays "Open" for the cylinder with the jumper wire. There is a problem in the wiring between the ECM and the P300 connector. There may be a problem with the ECM. Proceed to Test Step 8.

Test Step 6. Check the Harness between the ECM and the Valve Cover Base for a Short Circuit

1. Remove the electrical power from the ECM.

2. Disconnect the appropriate P300 connector.

3. Restore the electrical power to the ECM.

4. Perform the "Injector Solenoid Test" at least two times.

Expected Result:

All of the cylinders in the appropriate bank indicate "Open" on Cat ET.

Results:

• OK - All cylinders indicate "Open" on Cat ET. The ECM and the engine harness are OK. Proceed to Test Step 7.
• Not OK - One or more cylinders indicate "Short" on Cat ET. Note the cylinders that indicate "Short". Proceed to Test Step 8.

Test Step 7. Check the Injector Harness Under the Valve Cover for an Open Circuit or a Short Circuit

1. Remove the electrical power from the ECM.

2. Remove the valve cover in order to gain access to the suspect injector.

3. Disconnect the harness connector from the suspect injector.

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Illustration 8	g01147088
Connector terminals for the injector solenoid

4. Thoroughly clean the terminals on the injector solenoid and on the harness connector.

5. Use a jumper wire to short circuit the connector terminals for the suspect injector. This will effectively replace the injector solenoid with a short circuit.

6. Restore the electrical power to the ECM.

7. Perform the "Injector Solenoid Test" at least two times.

Note: The injector solenoid that shares the supply wire of the injector that is short circuited may indicate a false test result. Disregard this test result.

8. Remove the electrical power from the ECM.

9. Remove the jumper wire from the injector connector. This will effectively replace the injector solenoid with an open circuit.

10. Restore the electrical power to the ECM.

11. Perform the "Injector Solenoid Test" at least two times.

12. Remove the electrical power from the ECM.

Expected Result:

Cat ET displays "Short" for the cylinder with the jumper wire and "Open" when the jumper wire is removed.

Results: