8101A 3 Mercury CONNECTING ROD AND CAP ASSEMBLY

Illustration 1 g00835065
SchematicTest Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect the J1/P1 connector at the Electronic Control Module (ECM), the J3/P3 machine connector, and the J155/P155 crank without injection connector. Refer to 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 of 6.0 N m (55 lb in).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 appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with the harness and/or the wiring.Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 2. Check the Status on the Electronic Service Tool
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position.
Observe the status for "Crank w/o Injection" on Cat ET.
Turn the keyswitch to the OFF/RESET position.
Remove connector HHH (engine run) and install connector JJJ (crank w/o inject).
Turn the keyswitch to the ON position.
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 inject) is installed.Results:
OK - The feature is working properly.Repair: Refer to 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
Illustration 2 g00936439
P1 ECM connector (ECM side)
Turn the keyswitch to the OFF/RESET position.
Disconnect the J1/P1 ECM connector and the J155/P155 crank without injection connector.
Measure the resistance between the following terminals:
P1:24 (crank w/o inject (NC)) to P1:29 (digital return)
P1:24 (crank w/o inject (NC)) to P1:25 (crank w/o inject (NO))
P1:24 (crank w/o inject (NC)) to chassis ground
P1:25 (crank w/o inject (NO)) to chassis ground
P1:25 (crank w/o inject (NO)) to P1:29 (digital return)Expected Result:The resistance is greater than 20,000 Ohms.Results:
OK - The resistance is acceptable. Proceed to Test Step 4.
Not OK - The resistance is not acceptable. 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. Stop.Test Step 4. Check the Resistance through the Harness
Illustration 3 g00936439
P1 ECM connector (ECM side)
Install connector HHH (engine run) at J155/P155.
Measure the resistance between P1:24 (crank w/o inject (NC)) and P1:29 (digital return).
Remove connector HHH (engine run) and install connector HHH (crank w/o inject) at J155/P155.
Measure the resistance between P1:25 (crank w/o inject (NO)) and P1:29 (digital return).Expected Result:The resistance is less than 10 Ohms for each measurement.Results:
OK - The resistance is within acceptable limits. Proceed to Test Step 5.
Not OK - The resistance is not acceptable. There is an open circuit or excessive resistance in the harness.Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 5. Short the Inputs at the ECM
Illustration 4 g00936439
J1/P1 breakout
Verify that the keyswitch is in the OFF/RESET position and install a 7X-1715 Adapter Cable (40 Pin Breakout T) at the J1/P1 ECM connector.
Use a suitable piece of wire to short P1:24 (crank w/o inject (NC)) and P1:29 (digital return) at the breakout.
Turn the keyswitch to the ON position.
Observe the status for "Crank w/o Injection" on Cat ET.
Turn the keyswitch to the OFF/RESET position.
Move the one end of the wire from P1:24 (crank w/o inject (NC)) to P1:25 (crank w/o inject (NO)). Leave the other end of the wire in P1:29 (digital return).
Turn the keyswitch to the ON position.
Observe the status for "Crank w/o Injection" on Cat ET.Expected Result:The status reads "On" when the wire short is installed in P1:24 (crank w/o inject (NC)). The status reads "OFF" when the wire short is installed in P1:25 (crank w/o inject (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 Troubleshooting, "Replacing the ECM" before replacing the ECM. Stop.