Injector Solenoid Circuit - Test. Use this procedure for the following conditions. Inspect the Electrical Connectors and the Wiring, страница 6

• OK - Cat ET displays the correct status during the test.

Repair: The harness wiring is OK. There may be a problem with the injector. Use a multimeter to check the resistance of the suspect injector solenoid.The correct resistance of each injector solenoid is 1.06 ± 0.05 Ohms at 25 °C (77 °F).If the resistance of the solenoid is not within specifications replace the faulty injector. Verify that the problem is resolved.If the resistance of the solenoid is within specifications the problem may be intermittent. If the problem is intermittent, refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors".

STOP

• Not OK - Cat ET did not display the correct status during the test.

Repair: There is a problem with the injector harness under the valve cover. There may be a problem with a connector. Repair the wiring and/or the connector, when possible. Replace parts, if necessary.

STOP

Test Step 8. Check the ECM for Proper Operation

1. Remove the electrical power from the ECM.

2. Fabricate a jumper that is long enough to reach from the P2 ECM connector to the engine ground stud. Crimp a connector socket to one end of the jumper wire.

3. Disconnect the P2 connector.

4. Remove the supply wire from the terminal location for the suspect injector at the ECM connector. Install the jumper wire into this socket.

5. Connect the J2/P2 ECM connectors.

6. Verify that the ECM will detect an open circuit for the suspect injector:
1. Ensure that the jumper wire is not in contact with a ground source or another circuit. Do not touch the jumper wire during the test. A strong electrical shock hazard is present at the jumper wire while the test is running.

2. Restore the electrical power to the ECM.

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

4. Remove the electrical power from the ECM.

Cat ET displays "Open" for the two injectors that share the supply wire.

7. Verify that the ECM detects a short circuit for the suspect injector:
1. Connect the jumper wire to the engine ground stud. Do not touch the jumper wire during the test. A strong electrical shock hazard is present at the jumper wire while the test is running.

2. Restore the electrical power to the ECM.

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

4. Remove the electrical power from the ECM.

Cat ET displays "Short" for the two injectors that share the supply wire.

Expected Result:

Cat ET displays the correct status for each test circuit.

Results:

• OK - The ECM detects the correct status of the circuit.

Repair: The ECM is OK. The problem is in the engine harness or in a connector. Inspect the connectors for moisture and for corrosion. Repair the wiring and/or the connector, when possible. Replace parts, if necessary. Clear all diagnostic codes after you complete this test step.

STOP

• Not OK - The ECM does not detect the correct status of the circuit.

Repair: There is a problem with the ECM. Replace the ECM. Refer to Troubleshooting, "Replacing the ECM". Verify that the problem is resolved.