878609 Mercury SCREW, (#10-16 x .600)

The following background information is related to this procedure:DEF InjectorThe DEF injector controls the flow of DEF into the exhaust stream. The DEF injector is controlled by the ECM.DEF Dosing Injector OverrideThis override allows the user to test the electrical circuit for the DEF injector. The override commands the DEF injector to open. This override only operates when there is no engine speed.
Illustration 1 g06370898
Schematic diagram for the DEF injector
Note: All connectors may not be shown. Refer to the Electrical Schematic for the application for details of any connectors between the DEF injector connector and the ECM connectors.
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect the connector for the DEF injector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
B. Thoroughly inspect any connectors between the DEF injector and the ECM. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Check the harness for corrosion, abrasion, and pinch points from the DEF Injector to the ECM.
Note: Do not disconnect the ECM connector at this stage. The ECM can only be disconnected and reconnected 10 times before damage to the harness connector may occur.
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 the seals are properly in place and ensure that the connectors are correctly coupled.
Use the electronic service tool to clear all logged diagnostic codes.
Use the electronic service tool to perform the "DEF Dosing Injector Override" to 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.
Proceed to Test Step 2.
2. Check for Active Diagnostic Codes
A. Turn the keyswitch to the OFF position.
B. Connect the electronic service tool to the diagnostic connector.
C. Turn the keyswitch to the ON position.
D. Use the electronic service tool to perform the "DEF Dosing Injector Override".
E. Verify if any of the diagnostic codes that are listed in Table 1 are active.
F. Turn the keyswitch to the OFF position.
Diagnostic codes
Result: A 3361–5 diagnostic code is active.
Proceed to Test Step 3.
Result: A 3361–6 diagnostic code is active.
Proceed to Test Step 6.
Result: No diagnostic codes are active. There may be an intermittent fault.
Repair: Use the electronic service tool to perform a Wiggle Test.
If no faults are found, return the unit to service.
If the Wiggle Test identifies a fault, investigate the cause.
3. Create a Short Circuit at the Harness Connector for the DEF Injector
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the DEF injector.
C. Fabricate a jumper wire that is 150 mm (6 inch) long.
D. Install the wire between the terminal 1 and terminal 2 on the harness connector for the DEF injector to create a short circuit.
E. Turn the keyswitch to the ON position. Use the electronic service tool to perform the "DEF Dosing Injector Override".
F. Check for active diagnostic codes.
G. Remove the jumper wire from the connector for the DEF injector.
Short circuit
Result: A 3361-5 diagnostic code was active before installing the jumper. A 3361-6 diagnostic code is active when the jumper is installed - There is a fault in the DEF injector.
Repair: Install a replacement DEF injector. Refer to Disassembly and Assembly, DEF Injector and Mounting - Remove and Install.
Use the electronic service tool to perform the "DEF Dosing Injector Override" to check that the repair eliminates the fault.
Result: A 3361-5 diagnostic code is still active with the jumper installed.
Remove the jumper. Reconnect all connectors. Proceed to Test Step 4.
4. Check the Wiring Between the DEF Injector and the Interface Connector (if equipped) for an Open Circuit
Note: This step is only applicable if an interface connector is installed between the DEF injector and the ECM. Refer to the Electrical Schematic for the application for more information. Proceed to Test Step 5 if no interface connector is installed.
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the DEF injector. Disconnect the interface connector between the DEF injector and the ECM.
C. Use a suitable multimeter to measure the resistance between terminal 1 on the harness connector for the DEF injector and the appropriate pin/terminal on the interface connector.
Use a suitable multimeter to measure the resistance between terminal 2 on the harness connector for the DEF injector and the appropriate pin/terminal on the interface connector.
Less than 2 Ohms
Result: At least one of the measured resistances is greater than 2 Ohms. There is a fault in the wiring between the DEF injector connector and the interface connector.
Repair: Repair the faulty wiring or replace the faulty wiring.
Use the electronic service tool to perform the "DEF Dosing Injector Override" to check that the repair eliminates the fault.
Result: The measured resistance is less than 2 Ohms.
Reconnect all connectors. Proceed to Test Step 5.
5. Check the Wiring to the ECM for an Open Circuit
A. Turn the keyswitch to the OFF position.
B. Disconnect the P2 connector. Disconnect the connector for the DEF injector.
C. Inspect the P2/J2 connectors for damage or corrosion. Refer to Troubleshooting, Electrical Connectors - Inspect for more information.
D. Perform a 30 N (6.7 lb) pull test on P2:13 and P2:26.
E. Use a suitable multimeter to measure the resistance between terminal 1 on the harness connector for the DEF injector and P2:13.
Use a suitable multimeter to measure the resistance between terminal 2 on the harness connector for the DEF injector and P2:26.
Less than 2 Ohms
Result: At least one of the measured resistances is greater than 2 Ohms. The fault is in the wiring connected to the ECM connector.
Repair: Repair the faulty wiring or replace the faulty wiring.
Result: The resistance is less than 2 Ohms.
Contact the Dealer Solutions Network (DSN).
6. Create an Open Circuit at the DEF Injector
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the DEF injector.
C. Turn the keyswitch to the ON position. Use the electronic service tool to perform the "DEF Dosing Injector Override".
D. Check for active diagnostic codes.
Open circuit
Result: A 3361-6 diagnostic code was active before disconnecting the DEF