850454 1 Mercruiser PUMP ASSEMBLY, Circulating Water

Illustration 1 g01198125
Typical schematic
Illustration 2 g01288932
Sensors and mounting brackets (typical example)Test Step 1. Check for Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
Restore electrical power to the engine ECM.
Start the engine and run the engine until the engine is at the normal operating temperature.Note: If the engine will not start, monitor the engine rpm on Cat ET while the engine is being cranked. Cat ET may need to be powered from another battery while the engine is being cranked. Upon initial cranking, the status for engine speed may indicate that the engine speed signal is abnormal. This message will be replaced with an engine speed once the ECM is able to calculate a speed from the signal.
Wait at least 30 seconds for activation of the diagnostic codes. Look for these codes on Cat ET:
190-02
190-11
342-02
342-11Expected Result:One or both of the diagnostic codes that are listed above are logged or active.Note: If the engine will not start and Cat ET displayed 0 rpm during cranking, select "No Engine rpm".Results:
No Engine rpm - Engine rpm is not indicated on Cat ET. Proceed to Test Step 2.
Active or logged code - There is an active diagnostic code or a logged diagnostic code for an engine speed/timing sensor. Proceed to Test Step 3.Test Step 2. Check the Installation of the Sensors and the Brackets
Remove electrical power from the engine ECM.
The flange of the sensor should be flush against the engine in order to ensure proper operation.
Inspect the bracket in order to ensure that the installation allows the flange of the sensor to be flush against the engine.Verify that the bracket is not bent.Note: The bracket cannot be replaced separately.
Ensure that the O-ring has been installed on the sensor, and ensure that the O-ring is free of damage.
If either of the following diagnostic codes is active, there may be a problem with the assembly of the camshaft gear or the crankshaft gear:
190-11
342-11Expected Result:The sensors and the bracket are properly installed.Results:
OK - The sensors and the bracket are properly installed. Proceed to Test Step 3.
Not OK - The sensors and/or the bracket are not properly installed.Repair: Perform the following procedure in order to properly install the sensors and the bracket:
Loosen the bolt that holds the sensor mounting bracket to the engine.
Seat the sensor and tighten the bolt.If the sensor will not seat, repair the sensor or replace the sensor, as required.Note: The sensor must not be removed from the bracket.
Ensure that the sensor is properly oriented and that the harness is secured in the proper location.
Verify that the repair eliminates the problem.STOPTest Step 3. Inspect the Electrical Connectors and the Wiring
Illustration 3 g01197978
(1) Primary engine speed/timing sensor (2) Secondary engine speed/timing sensor
Thoroughly inspect the connectors for the engine speed/timing sensors (1) and (2). Refer to Troubleshooting, "Electrical Connectors - Inspect".
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Location of the P2 ECM connector (typical left side engine view)
Illustration 5 g01197972
P2 terminal locations for the engine speed sensors (P2-48) Primary engine speed/timing sensor + (P2-49) Primary engine speed/timing sensor - (P2-58) Secondary engine speed/timing sensor + (P2-59) Secondary engine speed/timing sensor -
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the engine speed/timing sensors.
Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from each sensor back to the ECM.Expected Result:All of the connectors, pins and sockets are completely coupled and/or inserted and 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 4.
Not OK - The connectors and/or wiring are not OK.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. 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 4. Measure the Senso