825051 Mercury PLATE

Illustration 1 g01393576
Schematic for the air starting motor system
Test Step 1. Inspect the Electrical Connectors and the Wiring
Set the engine control to the OFF/RESET position.
Illustration 2 g01392084
Location of the ECM connectors for the starting motor relay (typical left front side engine view)
(1) J2/P2 ECM connectors
Illustration 3 g01393572
Location of the connectors for the starting motor relay
(2) Starting motor relay
(3) Connector for the starting motor relay Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
Thoroughly inspect ECM connectors (1). Also, thoroughly inspect connectors (3) that are for starting motor relay (2).
Check the allen head screw for each of the ECM connectors for the proper torque.
Illustration 4 g01393581
Terminal locations at the P2 ECM connector for the starting motor circuit
(P2-10) Starting motor
(P2-20) Return
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the starting system.
Check the harness and wiring for abrasion and for pinch points from the starting system to the ECM. Expected Result:All connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - The components are not in good condition and/or at least one connection is improper.Repair: Perform the necessary repairs, when possible. Replace parts, if necessary.STOPTest Step 2. Check for Diagnostic Codes
Establish communication between the Caterpillar Electronic Technician (ET) and the ECM. Refer to Troubleshooting, "Electronic Service Tools", if necessary. Note: The 444-5 diagnostic code can only be detected when the output for the start command is on. The output is normally off when the engine control is in the COOLDOWN/STOP position or when the crank terminate relay is energized.
Wait for 30 seconds and check for an active 444-5 diagnostic code. If there is an active 444-5 diagnostic code, proceed to the “Results” for this Test Step. Otherwise, continue this procedure.
Check the logged codes. If there is a logged 444-6 diagnostic code, clear the code.
To prevent the engine from starting, shut off the gas supply. Note: The 444-6 diagnostic code can only be detected when the output for the start command is on. The output is normally on when the engine control is set from the "COOLDOWN/STOP" position to the "START" position. The output remains on until the crank terminate relay is energized.
Set the engine control to the START position for at least six seconds. Then set the engine control to the COOLDOWN/STOP position.
Check for a logged 444-6 diagnostic code. Expected Result:When the engine control was in the COOLDOWN/STOP position, there was no active 444-5 diagnostic code.After the engine was cranked, there was no logged 444-6 diagnostic code.Results:
OK - No diagnostic codes were activated. Repair: The output for the start command seems to be OK at this time. The initial diagnostic code was probably caused by a poor electrical connection. If an intermittent electrical problem is suspected of causing the codes to be logged, refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK (444-5 diagnostic code) - A 444-5 diagnostic code was activated. This can be caused by an actual open circuit or by a short circuit to the +Battery side. Proceed to Test Step 3.
Not OK (444-6 diagnostic code) - After the engine was cranked, a 444-6 diagnostic code was activated. Proceed to Test Step 7.Test Step 3. Check for a Short Circuit to the +Battery Side
Gaseous fuel is present. Personal Injury or Death can result from an open flame or spark igniting the gaseous fuel causing an explosion and/or fire. Always use a gas detector to determine the presence of gaseous fuel when maintaining and servicing. Contact your local gas provider immediately for assistance in the event of a leak.
Note: Open sparks can be generated during this test.
Make sure that no combustible gas is present in the surrounding atmosphere.
Verify that the engine control is in the COOLDOWN/STOP position.
Disconnect the connector from the air start relay. Then reconnect the connector. Listen for an audible click from the relay. If the ambient noise is too loud, touch the air start relay when the relay is reconnected in order to feel the vibration. The relay will vibrate when the relay is de-energized and energized.Expected Result:There is no audible click and/or vibration when the air start relay is disconnected and reconnected. The relay is not energized when the engine control is in the STOP position.Results:
OK - There is no audible click and/or vibration when the air start relay is disconnected and connected. There is no short circuit to the +Battery side. There is an open circuit. Proceed to Test Step 4.
Not OK - There is an audible click and/or vibration when the air start relay is disconnected and connected. The relay is receiving power when the engine control is in the STOP position. Proceed to Test Step 6.Test Step 4. Create a Short Circuit at the Starting Motor Relay
Set the engine control to the OFF/RESET position.
Disconnect the harness connector from the air start relay.
Install a jumper wire between the two terminals of the harness connector at the air start relay.
Set the engine control to the COOLDOWN/STOP position.
Wait for 30 seconds. Check for a 444-5 diagnostic code. Expected Result:A 444-5 diagnostic code was not activat