6721M Mariner DRIVESHAFT HOUSING (SHORT)

Table 1
Diagnostic Codes Table    
J1939 Code and Description    Conditions which Generate this Code    System Response    
677-5 Engine Starter Motor Relay : Current Below Normal     The Electronic Control Module (ECM) detects an open circuit and/or a short to the +Battery in the circuit for the Starter Motor Magnetic Switch (SMMS). The ECM can only detect this condition when the SMMS is not energized.     The code is logged.    
677-6 Engine Starter Motor Relay : Current Above Normal     The ECM detects a short circuit to ground in the circuit for the SMMS. The ECM can only detect this condition when the SMMS is energized.    The engine control system controls all aspects of engine start and stop functionality. In order to crank the engine, the ECM sends a signal to the SMMS. Current will flow to the starting motor through the contacts of the SMMS. The starting motor will begin to crank the engine.The ECM receives a request to crank the engine over the CAN data link from the Electronic Modular Control Panel 3 (EMCP). Ensure that the "Engine State Control Input Configuration" is configured to "CAN Input" if an EMCP is installed on the engine.If the "Engine State Control Input Configuration" parameter is configured to "Hardwired", a switch input will be used by the ECM for engine starting. The signal at terminal location P1-40 will be used for engine starting. Table defines the functionality of the switch input.
Table 2
ECM Switch Input     Switch Input     Engine State    
P1/J1-40     −Battery     Start/Run    
P1/J1-40     +Battery     Stop    Refer to Troubleshooting, "Configuration Parameters".The starting system can be configured with an air starting system, an electrical starting motor, or both. Selection of the starting system is independent of ECM control. If both starting systems are installed on the engine, a starter select switch must be installed. The switch will be used by the operator to select the appropriate starting system.The ECM will crank the engine until the programmed "Crank Terminate RPM" has been reached. If the engine fails to reach the "Crank Terminate RPM" before the programmed "Crank Duration" period, the ECM will stop cranking the engine. The ECM will then allow the starter to cool for a period that is equal to the "Crank Duration" before starting the next crank cycle. The process will be repeated for a number of times that is equal to the programmed "Maximum Number of Crank Cycles". When the "Maximum Number of Crank Cycles" has been reached, the process will be aborted and Caterpillar Electronic Technician (ET) will display "OVERCRANK". The process will be restarted when the next start request is received by the ECM.Refer to Troubleshooting, "Configuration Parameters" for the available ranges and default settings of the following parameters:
"Crank Duration"
"Crank Terminate RPM"
"Maximum Number of Crank Cycles"Note: If the "Crank Duration" or "Maximum Number of Crank Cycles" are programmed to 0, the ECM will not crank the engine.
Illustration 1 g02197774
Schematic for the starting circuitTest Step 1. Inspect Electrical Connectors and Wiring
Remove electrical power from the ECM.
Illustration 2 g02164341
Location of ECM connectors (1) P1/J1
Thoroughly inspect the ECM connectors. Inspect all of the other connectors for the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g02175714
Terminal locations at the P1 ECM connector for the starting circuit (43) SMMS driver (51) SMMS driver
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. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and the wiring for abrasion and for pinch points.Expected Result:All connectors, pins, and sockets are coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The connectors 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 coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check for Active Diagnostic Codes for the SMMS
Connect Cat ET to the service tool connector.
Restore electrical power to the ECM.
Monitor the active diagnostic code screen on Cat ET. Check for an active -5 diagnostic code for the SMMS.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Proceed to the "Diagnostic Overrides" screen on Cat ET. Activate the override for the starting system.
Monitor the active diagnostic code screen on Cat ET. Check for a -6 diagnostic code for the SMMS.Note: Wait at least 30 seconds in order for the diagnostic codes to