855502 Mercruiser PUMP ASSEMBLY-SEAWATER

Illustration 1 g01222505
Schematic
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P1 ECM connector
(P1-35) Crank without injection input (NC)
(P1-44) Crank without injection input (NO)
Illustration 3 g01224241
Component location
(1) Crank without injection Test Step 1. Inspect Electrical Connectors and Wiring
Remove the electrical power from the ECM.
Thoroughly inspect the J1/P1 connector for the Electronic Control Module (ECM) and the connector for the crank without injection. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the sensor connectors that are associated with the active diagnostic code.
Check the ECM connector (allen head screw) for the proper torque. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and wiring for abrasions and for pinch points from the sensors back to the ECM. Expected Result:All connectors, pins, and sockets are completely inserted and coupled. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: 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 completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check the Status on Caterpillar Electronic Technician (ET)
Connect Cat ET to the service tool connector.
Restore the electrical power to the ECM.
Observe the status for "Crank w/o Injection" on Cat ET.
Remove the electrical power from the ECM.
Remove connector HHH (engine run) and install connector JJJ (crank w/o injection input).
Restore the electrical power to the ECM.
Observe the status for "Crank w/o Injection" on Cat ET. Expected Result:The status reads "Off" when connector HHH (engine run) is installed. The status reads "On" when connector JJJ (crank w/o injection input) is installed.Results:
OK - The feature is working properly.Repair: Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent.STOP
Not OK - The feature is not working properly. Proceed to Test Step 3.Test Step 3. Check the Harness for Shorts
Disconnect the J1/P1 ECM connector and the connector for the crank without injection.
Measure the resistance between the following terminals:
P1-35 crank w/o injection input (NC) and P1-44 crank w/o injection input (NO)
P1-35 crank w/o injection input (NC) and chassis ground
P1-44 crank w/o injection input (NO) and chassis groundExpected Result:The resistance is 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 circuit in the harness between the connector and the ECM.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 4. Check the Resistance through the Harness
Install connector HHH (engine run) at the connector for the crank without injection.
Measure the resistance between P1-35 crank w/o injection input (NC) and chassis ground.
Remove connector HHH (engine run) and install connector HHH (crank w/o injection input) at the connector for the crank without injection.
Measure the resistance between P1-44 crank w/o injection input (NO) and chassis ground. Expected Result:The resistance is less than 5 Ohms for each measurement.Results:
OK - The resistance is less than 5 Ohms for each measurement. Proceed to Test Step 5.
Not OK - The resistance is more than 5 Ohms for a measurement. There is an open circuit or excessive resistance in the harness.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 5. Short the Inputs at the ECM
Remove the electrical power from the ECM and install a 208-0059 Adapter Cable As (70-Pin Breakout) at the J1/P1 ECM connector.
Use a suitable piece of wire to short P1-35 crank w/o injection input (NC) and chassis ground.
Restore the electrical power to the ECM.
Observe the status for "Crank w/o Injection" on Cat ET.
Remove the electrical power from the ECM.
Move the one end of the wire from P1-35 crank w/o injection input (NC) to P1-44 crank w/o injection input (NO). Leave the other end of the wire connected to chassis ground.
Restore the electrical power to the ECM.
Observe the status for "Crank w/o Injection" on Cat ET. Expected Result:The status reads "Off" when the wire short is installed in P1-35 crank w/o injection input (NC). The status reads "On" when the wire short is installed in P1-44 crank w/o injection input (NO).Results:
OK - The ECM is functioning properly. The problem is in the wiring harness.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOP
Not OK - The correct inputs appear at the ECM, but the ECM is not responding properly.Repair: Verify your results. Replace the ECM. Refer to electronic troubleshooting Troubleshooting, "Replacing the ECM" before replacing the ECM.STOP