862031T Mercruiser ALTERNATOR ASSEMBLY (65 Amp)

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Schematic ( 3176C and 3196)
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Schematic ( 3406E and 3456)Note: Do not attempt to disconnect the pigtail from the sensor. The pigtail is sealed in the connector.
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P2 ECM connectorTest Step 1. Check for Diagnostic Codes
Connect the Caterpillar Electronic Technician (Cat ET) to the service tool connector.
Turn the keyswitch to the ON position.
Verify whether any of the following diagnostic codes are active or logged:
320-02 Speed/Timing Sensor Loss of Signal
320-11 Speed/Timing Sensor mechanical failure
342-02 Loss of Secondary Engine Speed signal
342-11 Secondary Engine Speed Sensor mechanical failure
If the diagnostic code is logged but not active, run the engine until the engine is at normal operating temperature. The problem may only occur when the engine is at the normal operating temperature.
If the engine will not start, monitor the engine speed 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 in order to ensure that Cat ET does not reset.Note: 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.Expected Result:One or more of the diagnostic codes that are listed above are logged or active.Results:
Diagnostic Codes - There is a logged diagnostic code or an active diagnostic code for the engine speed/timing sensors. Proceed to Test Step 3.
No Diagnostic Codes - There are no diagnostic codes for the engine speed/timing sensors, but the engine is not running properly.Repair: Proceed to the appropriate topic in Troubleshooting, "Troubleshooting without a Diagnostic Code".STOP
No Engine rpm - Engine rpm is not indicated on Cat ET. Proceed to Test Step 2.Test Step 2. Check the Installation of the Sensors and the Brackets
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Sensors and mounting brackets (typical example)
The flange of the sensor must 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 engine:
320-11 Speed/Timing Sensor mechanical failure
342-11 Secondary Engine Speed Sensor mechanical failureExpected 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 - 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 Electrical Connectors and Wiring
Turn the keyswitch to the OFF position.
Thoroughly inspect the J2/P2 ECM connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on the following wires in the P2 ECM connector that are associated with the engine speed/timing sensors:
P2:48 (Primary Engine Speed/Timing +)
P2:49 (Primary Engine Speed/Timing -)
P2:58 (Secondary Engine Speed/Timing +)
P2:59 (Secondary Engine Speed/Timing −)
Ensure that the latch tab on the connector is properly latched and ensure that the latch tab is fully latched.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Ensure that the harness wiring is not pulled too tightly. When the harness wiring is pulled too tightly, vibrations or movement can cause intermittent connectio