888416T04 Mercruiser HARNESS ASSEMBLY, DTS

Illustration 1 g00895305
Typical exampleTest Step 1. Check for Connector Damage
Turn the keyswitch to the OFF position.
Turn the circuit breaker for the engine to the OFF position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the customer connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the harness and the wiring for abrasion and pinch points.Expected Result:The connectors and wiring should be free of the following problems:damage, corrosion, abrasion and incorrect attachment.Results:
OK - The connectors and wiring are free of any problems. Proceed to test step 2.
Not OK - The connectors and/or wiring need repair.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 2. Check the Status of the "Crank without Injection" on the Caterpillar Electronic Technician (ET).
Turn the circuit breaker for the engine to the ON position.
Install the Cat ET.
Turn the keyswitch to the ON position. The engine should be OFF.
Observe the "Crank without injection" on the Cat ET.
Turn the keyswitch to the OFF position.
Disconnect P24-HHH and connect P24-JJJ to J24.
Turn the keyswitch to the ON position. The engine should be OFF.
Observe the "Crank without injection" on the Cat ET.Expected Result:The Cat ET should display "OFF" when HHH is installed. The Cat ET should display "ON" when JJJ is installed.Results:
OK - The Cat ET displays "OFF" when HHH is installed. The Cat ET displays "ON" when JJJ is installed.Repair: The input is operating normally. Stop.
Not OK - The Cat ET does not display "OFF" when HHH is installed. The Cat ET does not display "ON" when JJJ is installed. Proceed to test step 3.Test Step 3. Check for a Short in the Harness between the ECM and the Connector for the "Crank without Injection".
Turn the keyswitch to the OFF position.
Turn the circuit breaker for the engine to the OFF position.
Disconnect ECM connector J1/P1.
Disconnect the connector J24/P24 for the "Crank without Injection".
Measure the resistance between P1-25 and P1-29 at ECM connector P1.
Measure the resistance between P1-29 and P1-24 at ECM connector P1.
Measure the resistance between P1-24 and P1-25 at ECM connector P1.
Measure the resistance between P1-25 and the engine ground at ECM connector P1.
Measure the resistance between P1-24 and the engine ground at ECM connector P1.Expected Result:The resistance should be greater than 20,000 Ohms.Results:
OK - The resistance is greater than 20,000 Ohms. Proceed to test step 4.
Not OK - The resistance is less than 20,000 Ohms. There is a short in the harness between the connector J24 and the ECM.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 4. Check for an Open in the Harness between the ECM and the Connector for the "Crank without Injection".
Connect plug P24-HHH to connector J24.
Measure the resistance between P1-24 and P1-29 at ECM connector P1.
Disconnect plug P24-HHH and connect plug P24-JJJ.
Measure the resistance between P1-25 and P1-29 at ECM connector P1.Expected Result:The resistance should not be greater than 10 Ohms.Results:
OK - The resistance is not greater than 10 Ohms. Proceed to test step 5.
Not OK - The resistance is greater than 10 Ohms. There is an open or excessive resistance in the harness or connectors. The plug may have an open.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Repair the plug or replace the plug. Stop.Test Step 5. Create a Short at the ECM Connector for the "Crank without Injection" Inputs.
Remove the wires from ECM connector P1-25 and P1-24. Install wire jumpers into the sockets for P1-25 and P1-24.
Remove the wire from ECM connector P1-29. Install a wire jumper into the socket for P1-29.
Use a suitable piece of wire and short P1-24 to P1-29.
Reconnect ECM connector J1/P1.
Turn the circuit breaker for the engine to the ON position.
Turn the keyswitch to the ON position. The engine should be OFF.Note: Disconnecting the common sensor wire from the ECM will generate an open circuit diagnostic code for all sensors that are connected to the sensor common. Troubleshoot the original diagnostic code. Delete the logged diagnostic codes when you are finished.
Observe the status of the "Crank without injection" on the Cat ET.
Turn the keyswitch to the OFF position.
Remove the wire short.
Insert the wire short between P1-25 and P1-29.
Turn the keyswitch to the ON position. The engine should be OFF.
Observe the status of the "Crank without injection" on the Cat ET.
Turn the keyswitch to the OFF position.
Turn the circuit breaker for the engine to the ON position.
Remove the wire short. Remove the wire jumpers.
Restore the wiring to the original configuration.Expected Result:The Cat ET should display "OFF" when the wire short is installed between P1-24 and P1-29. The Cat ET should display "ON" when the wire short is installed between P1-25 and P1-29.Results:
OK - The ECM reads the correct signal when the inputs are shorted at P1. The harness is faulty between the ECM and the connector J24/P24.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.
Not OK - The ECM is not reading the inputs from the "Crank without injection".Repair: Replace the ECM. Refer to Troubleshooting, "Replacing the ECM". Stop.