875813 Volvo.Penta Contact

Table 2
Component Electrical Checkout
Engine Starter Motor Relay Attempt to start the engine. Once the ECM attempts to energize the relay, the code will become active. Refer to the machine-specific schematic for the "Engine Starter Motor Relay" wiring circuit. During the following procedure, refer to the electrical schematic for the application.Complete the procedure in the order in which the steps are listed.
Table 3
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Check that the fuses are not blown.
B. Inspect the terminals on the start relay. Refer to Troubleshooting, "Electrical Connector - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the start relay.
D. Check the screw for the ECM connector for the correct torque of 6 N m (53 lb in).
E. Check the harness for abrasion and pinch points from the start relay back to the ECM.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all of the seals are properly in place and ensure that the connectors are correctly coupled.
Replace any blown fuses.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points. The fuses are not blown.
Proceed to Test Step 2.
2. Check for Active Diagnostic Codes
A. Connect the electronic service tool to the diagnostic connector.
B. Turn the keyswitch to the ON position.
Note: Do not start the engine.
C. Use the electronic service tool to check for active diagnostic codes.
Diagnostic codes
Result: Diagnostic code 677-5 is active or recently logged.
Proceed to Test Step 3.
Result: Diagnostic code 677-6 is active or recently logged.
Proceed to Test Step 4.
3. Create a Short Circuit at the Relay Connector
A. Turn the keyswitch to the OFF position.
B. Remove the start relay.
C. Fabricate a jumper wire. Install the jumper wire between terminal 1 and terminal 2 on the harness connector for the start relay.
D. Turn the keyswitch to the ON position.
E. Perform the appropriate electrical checkout. Refer to Table 2.
F. Use the electronic service tool to check for active diagnostic codes. Wait at least 30 seconds for activation of the diagnostic codes.
G. Turn the keyswitch to the OFF position and remove the jumper wire.
Diagnostic code
Result: A 677-6 diagnostic code is active with the jumper installed.
Repair: Install a replacement start relay.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: The 677-5 diagnostic code is still active.
Repair: There is an open circuit for the starter motor relay in the wiring harness. Repair or replace the wiring harness.
4. Create an Open Circuit at the Relay
A. Turn the keyswitch to the OFF position.
B. Disconnect the start relay.
C. Turn the keyswitch to the ON position.
D. Perform the appropriate electrical checkout. Refer to Table 2.
E. Use the electronic service tool to check for active diagnostic codes. Wait at least 30 seconds for activation of the diagnostic codes.
Diagnostic codes
Result: A 677-5 diagnostic code is active with the relay disconnected.
Repair: Install a replacement start relay.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: The 677-6 diagnostic code is still active with the relay disconnected.
Repair: There is a short circuit to ground or short circuit to a power source in the harness. Repair or replace the wiring harness.
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).