20116 Mercury GROMMET, CHOKE KNOB

Illustration 1 g01250692
Schematic for the engine prelube system
Test Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Turn the battery disconnect switch to the OFF position.
Illustration 2 g01250707
Locations of the components for the engine prelube system (typical left side engine view)
(1) Engine prelube relay
(2) Connector for the engine prelube system
(3) J1/P1 ECM connectors
Thoroughly inspect the terminal connections at relay (1). Also, thoroughly inspect connectors (2) and (3). Inspect all of the other connectors for the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01250714
Terminal locations at the P1 ECM connector for the engine prelube system
(P1-13) Prelube relay
(P1-18) Digital return
Illustration 4 g01155187
Terminal locations at the connector for the engine prelube relay
(Terminal 1) Prelube relay
(Terminal 2) Digital return
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 allen head screw for each of the ECM connectors and the machine connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and connectors appear to be 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 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.
Turn the battery disconnect switch to the ON position.
Turn the keyswitch to the ON position.
Proceed to the "Diagnostic Overrides" screen on Cat ET.
Activate the override for the engine prelube system.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Turn the keyswitch to the OFF position.
Determine if the problem is related to an open circuit diagnostic code 05 or a short circuit diagnostic code 06. Expected Result:No diagnostic codes are active.Results:
OK - No diagnostic codes are active.Repair: The problem may have been related to a faulty connection in the harness. Carefully reinspect the connectors and wiring. If an intermittent electrical problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Active 06 Code - A short circuit diagnostic code (06) is active at this time. Proceed to Test Step 3.
Active 05 Code - An open circuit diagnostic code (05) is active at this time. Proceed to Test Step 4.Test Step 3. Create an Open at the Prelube Relay
Disconnect the wires from terminals G and S at the prelube relay.
Turn the keyswitch to the ON position.
Proceed to the "Diagnostic Overrides" screen on Cat ET.
Activate the prelube override.
Monitor the active diagnostic code screen on Cat ET. Check for an active open circuit diagnostic code (05) for the prelube relay. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Turn the keyswitch to the OFF position. Expected Result:An open circuit diagnostic code 05 is now active for the prelube relay.Results:
OK - A short circuit diagnostic code (06) was active before disconnecting the wiring. An open circuit diagnostic code (05) became active after disconnecting the wiring.Repair: There is a problem with the prelube relay. Temporarily connect a new prelube relay to the harness, but do not install the new relay. Verify that there are no active diagnostic codes for the new relay. If there are no active diagnostic codes for the relay, permanently install the new prelube relay. Clear any logged diagnostic codes.STOP
Not OK - An short circuit diagnostic code 06 remains active for the prelube relay. The problem is in the harness between the ECM and the prelube relay. There may be a problem with the ECM. Restore the wiring to the original configuration. Proceed to Test Step 5.Test Step 4. Create a Short at the Prelube Relay
Disconnect the wires from terminals G and S at the prelube relay.
Short circuit the two wires from the prelube relay.
Turn the keyswitch to the ON position. Note: Monitor the "Active Diagnostic Codes" screen on Cat ET after the wires have been shorted.
Proceed to the "Diagnostic Overrides" screen on Cat ET.
Activate the prelube override.
Wait at least 30 seconds for activation of the short circuit diagnostic code 06.
Turn the keyswitch to the OFF position. Expected Result:A short circuit diagnostic code 06 is active when the wires are shorted. An open circuit diagnostic code 05 is active when the wires are not shorted.Results:
OK - A short circuit diagnostic code 06 is active when the wires are shorted. An open circuit diagnostic code 05 is active when the wires are not shorted.Repair: The engine harness and the ECM are OK. There is a problem with the prelube relay. Temporarily connect a new prelube relay to the harness, but do not install the new relay. Verify that there are no active diagnostic codes for the new relay. If there are no active diagnostic codes for the relay, permanently install the new prelube relay. Clear any logged diagnostic codes.STOP
Not OK - The open circuit diagnostic code 05 remains active when the wires are shorted. The problem is in the harness between the ECM and the prelube relay. There may be a problem with the ECM. Restore the wiring to the original configuration. Proceed to Test Step 5.Test Step 5. Check the Operation of the ECM
Disconnect the J1/P1 ECM connectors.
Fabricate two jumper wires that are long enough to create a short circuit at the ECM connector. Crimp connector sockets to one end of each of the jumper wires.
Remove the wires from terminal locations P1-13 and P1-18 at the ECM connector. Install the jumper wir