34897 Mercruiser GASKET, WATER PUMP MOUNTING

The following background information is related to this procedure:Coolant Diverter ValveThe coolant diverter valve controls the flow of coolant to the heater in the Diesel Exhaust Fluid (DEF) pump and the DEF tank. When required, the valve is opened to allow hot coolant to circulate through the DEF pump and the DEF tank. This flow allows the coolant to heat the DEF to a useable temperature.DEF Coolant Diverter Valve Solenoid OverrideThe override is used to check the solenoid and diverter valve harness. This override will open the coolant diverter valve, allowing coolant to flow through the DEF pump and the DEF tank. This test can be used to verify that the coolant diverter valve is working correctly.This override will only enable with the engine running at idle prior to the DEF system priming to operating pressure.
Illustration 1 g06370226
Schematic diagram for the coolant diverter valve
Note: All connectors may not be shown. Refer to the Electrical Schematic for the application for details of any connectors between the coolant diverter valve connector and the ECM connectors.
Table 2
Troubleshooting Test Steps Values Results
1. Check the Battery Voltage
A. Turn the keyswitch to the OFF position.
B. Use a suitable multimeter to measure the battery voltage.
At least 12.5 V for a 12 V system
At least 25V for a 24V system
Result: The battery voltage is lower than the expected range.
Repair: Refer to Troubleshooting, Battery Problem to investigate the cause of low battery voltage.
Result: The battery voltage is within the expected range.
Proceed to Test Step 2.
2. Check the Voltage at the Coolant Diverter Valve Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the coolant diverter valve.
C. Turn the keyswitch to the ON position.
D. Use a suitable multimeter to measure the voltage between terminal 1 on the harness connector for the coolant diverter valve and a suitable ground.
E. Turn the keyswitch to the OFF position.
At least 12.5 V for a 12 V system
At least 25V for a 24V system
Result: The voltage is lower than the expected range. There is a fault in the wiring between the coolant diverter valve and the SCR main relay.
Repair: Repair the faulty wiring or replace the faulty wiring.
Result: The voltage is within the expected range.
Proceed to Test Step 3.
3. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect the connector for the coolant diverter valve. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
B. Thoroughly inspect any connectors between the coolant diverter valve and the ECM. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Check the harness for corrosion, abrasion, and pinch points from the coolant diverter valve 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 Coolant Diverter Valve Solenoid 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 4.
4. 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. Start the engine.
E. Use the electronic service tool to perform the "DEF Coolant Diverter Valve Solenoid Override".
F. Verify if any of the diagnostic codes that are listed in Table 1 are active.
G. Turn the keyswitch to the OFF position.
Diagnostic codes
Result: A 3363–5 diagnostic code is active.
Proceed to Test Step 5.
Result: A 3363–6 diagnostic code is active.
Proceed to Test Step 8.
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.
5. Create a Short Circuit at the Harness Connector for the Coolant Diverter Valve
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the coolant diverter valve.
C. Fabricate a jumper wire that is 150 mm (6 inch) long.
D. Install the wire between the terminal 1 and terminal 4 on the harness connector for the coolant diverter valve to create a short circuit.
E. Turn the keyswitch to the ON position. Use the electronic service tool to perform the "DEF Coolant Diverter Valve Solenoid Override".
F. Check for active diagnostic codes.
G. Remove the jumper wire from the connector for the coolant diverter valve.
Short circuit
Result: A 3363-5 diagnostic code was active before installing the jumper. A 3363-6 diagnostic code is active when the jumper is installed - There is a fault in the coolant diverter valve.
Repair: Install a replacement coolant diverter valve.
Use the electronic service tool to perform the "DEF Coolant Diverter Valve Solenoid Override" to check that the repair eliminates the fault.
Result: A 3363-5 diagnostic code is still active with the jumper installed.
Remove the jumper. Reconnect all connectors. Proceed to Test Step 6.
6. Check the Wiring Between the Coolant Diverter Valve and the Interface Connector (if equipped) for an Open Circuit
Note: This step is only applicable if an interface connector is installed between the coolant diverter valve and the ECM. Refer to the Electrical Schematic for the application for more information. Proceed to Test Step 7 if no interface connector is installed.
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the coolant diverter valve. Disconnect the interface connector between the coolant diverter valve and the ECM.
C. Use a suitable multimeter to measure the resistance between terminal 4 on the harness connector for the coolant diverter valve and the appropriate pin/terminal on the interface connector.
Less than 2 Ohms
Result: The resistance is greater than 2 Ohms - There is a fault in the wiring between the coolant diverter valve connector and the interface