812773T02 Mercruiser DRIVESHAFT, Upper

Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the engine ECM.
Illustration 1 g01186024
Location of the J1/P1 ECM connectors (typical left side engine view)
Thoroughly inspect the J1/P1 ECM connectors and the connectors for each switch. Also inspect each of the machine connectors that are in the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 2 g01243962
Terminal locations at the P1 ECM connector for the switch circuits
(P1-5) Digital return
(P1-49) Retarder switch (N/C)
(P1-54) Retarder switch (N/O)
Illustration 3 g01195660
Connector for the retarder switch
(A) Retarder switch (N/C)
(B) Digital return
(C) Retarder switch (N/O)
Perform a 45 N (10 lb) pull test on each of the wires for the suspect switch.
Check the torque of the allen head screw on each of the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from the switch back to the ECM.Expected Result:Allof the connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The harness and the connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or wiring.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. 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 for Active Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore the electrical power to the engine ECM.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Check the "Active Diagnostic Codes" screen for an active code that relates to one of the switches. Toggle the suspect switch as you monitor Cat ET for the active diagnostic code.
Remove electrical power from the engine ECM.Expected Result:A diagnostic code that is related to one of the switches is not active.Results:
OK - A diagnostic code that is related to one of the switches does not become active.Repair: The switches are operating normally. There may be an intermittent problem in the wiring harness or in a connector. Check the wiring harness and the connectors for an intermittent electrical problem. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - A diagnostic code that is related to one of the switches is active. Proceed to Test Step 3.Test Step 3. Create a short at the Connector for the Suspect Switch and Check for Diagnostic Codes
Disconnect the connectors for the suspect switch.
Fabricate a jumper wire that is long enough to connect two terminals at the connector for the suspect switch. Crimp a connector pin to both ends of the jumper wire.
Install the jumper wire between the terminals for switch (N/C) and digital return on the harness side of the connector for the suspect switch.
Restore the electrical power to the engine ECM.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Check the "Active Diagnostic Codes" screen on Cat ET for an active code that relates to the suspect switch.Also use Cat ET to check the status of the switch. The correct switch status will be "Released".
Remove electrical power from the engine ECM.
Install the jumper wire between the terminal for switch (N/O) and digital return on the harness side of the connector for the suspect switch.
Restore the electrical power to the engine ECM.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Check the "Active Diagnostic Codes" screen on Cat ET for an active code that relates to the suspect switch.Also use Cat ET to check the status of the switch. The correct switch status will be "Depressed".
Remove electrical power from the engine ECM.Expected Result:There are no active diagnostic codes and the switch status is correct.Results:
OK - There are no active diagnostic codes and the switch status is correct.Repair: There is a problem with the switch. Replace the switch. Verify that the problem is resolved.STOP
Not OK - There is either an active diagnostic code or the switch status is incorrect. The switch is OK. There is a problem in the harness between the connector for the suspect switch and the ECM. There may be a problem with the ECM. Proceed to Test Step 4.Test Step 4. Check the ECM for Proper Operation
Disconnect the J1/P1 ECM connectors.
Fabricate a jumper wire that is long enough to connect two terminals locations at the ECM connector. Crimp a connector socket to both ends of the jumper wire.
Remove the wires from the terminal locations that are for switch (N/C), switch (N/O), and digital return at the P1 ECM connector. Install the jumper wire between the terminal locations for switch (N/C) and digital return at the P1 ECM connector.
Connect the J1/P1 ECM connectors.
Restore the electrical power to the engine ECM.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Check the "Active Diagnostic Codes" screen on Cat ET for an active code that relates to the suspect switch.Also use Cat ET to check the status of the switch. The correct switch status will be "Released".
Remove electrical power from the engine ECM.
Disconnect the J1/P1 ECM connectors.
Remove the jumper wire from the terminal location for switch (N/C) at the P1 ECM connector.
Install the loose end of the jumper wire into the terminal location for switch (N/O) at the P1 ECM connector.
Connect the J1/P1 ECM connectors.
Restore the electrical power to the engine ECM.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Check the "Active Diagnostic Codes" screen on Cat ET for an active code that relates to the suspect switch.Also use Cat ET to check the status of the switch. The correct switch status will be "Depressed".
Remove electrical power from the engine ECM.Expected Result:There are no active diagnostic codes and the switch status is correct.Results:
OK - There are no active diagnostic codes and the switch status is correct.Repair: There is a problem in th