76596 Mercruiser SCREW, IGNITION AMPLIFIER (1-1/4")

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Locations of the temperature sensors (Right side view of the 3176C Engine)
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Locations of the temperature sensors (Top view of the 3176C Engine)
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Locations of the temperature sensors (Right side view of the 3406E Engine)
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Locations of the temperature sensors (Left side view of the 3406E Engine)
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Schematic for engine temperature sensorsTest Step 1. Verify All Active Diagnostic Codes.
Connect the electronic service tool to the cab data link connector.
Turn the keyswitch to the ON position. Wait at least 15 seconds for activation of the diagnostic codes.
Verify if any of the following diagnostic codes are active:
110-03 Engine Coolant Temperature open/short to +batt
110-04 Engine Coolant Temperature short to ground
172-03 Inlet Manifold Air Temperature open/short to +batt
172-04 Inlet Manifold Air Temperature short to ground
174-03 Fuel Temperature Sensor open/short to +batt
174-04 Fuel Temperature short to groundExpected Result:One or more of the preceding diagnostic codes are active.Results:
Yes - Proceed to Test Step 2.
No - Repair: If the preceding codes are logged but not active and the engine is not running properly, refer to Troubleshooting, "Troubleshooting without a Diagnostic Code". If the engine is running properly at this time, an intermittent condition may be causing the logged codes. Refer to Troubleshooting, "Electrical Connections - Inspect". STOPTest Step 2. Inspect Electrical Connectors And Wiring.
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Terminal locations for ECM
Thoroughly inspect ECM engine harness connector J2/P2 and the suspect sensor connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the sensor connector and the ECM connector that are associated with the active diagnostic code.Refer to Illustration 6.
Verify that the latch tab of the connector is properly latched and that the latch tab of the connector has returned to the fully latching position.
Check the ECM connector (allen head screw) for the proper torque of 6.0 N m (55 lb in).
Check the harness and wiring for abrasions and for pinch points from the sensor to the ECM.Expected Result:All connectors, pins, and sockets should be completely coupled and/or inserted. The harness and wiring should be free of corrosion, abrasion, and pinch points.Results:
OK - Proceed to Test Step 3.
Not OK - 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 3. Verify That The Diagnostic Code Is Still Active.
Turn the keyswitch to the ON position. Wait at least 15 seconds for activation of the diagnostic codes.
Access the "Active Diagnostic Code" screen of the electronic service tool. Check for active diagnostic codes.
Determine if the problem is related to an open circuit diagnostic code or a short circuit diagnostic code.Expected Result:A short circuit diagnostic code or an open circuit diagnostic code is active.Results:
SHORT Circuit - A short circuit diagnostic code is active at this time. Proceed to Test Step 4.
OPEN Circuit - An open circuit diagnostic code is active at this time. Proceed to Test Step 5.Test Step 4. Disconnect The Sensor In Order To Create An Open Circuit.
Turn the keyswitch to the OFF position.
Disconnect the sensor connector of the sensor with the short circuit diagnostic code.
Turn the keyswitch to the ON position. Wait at least 15 seconds for activation of the diagnostic codes.
Access the "Active Diagnostic Code" screen of the electronic service tool. Check for an active open circuit diagnostic code.Expected Result:An open circuit diagnostic code for the disconnected sensor is now active.Results:
OK - A short circuit diagnostic code was active before disconnecting the sensor. An open circuit diagnostic code became active after disconnecting the sensor. Proceed to Test Step 6.
Not OK - There is a short circuit between the sensor harness connector and the ECM. Leave the sensor disconnected. Proceed to Test Step 7.Test Step 5. Create A Short Circuit Between The Signal And The Common Terminals At The Sensor Connector.
Turn the keyswitch to the ON position.
Fabricate a jumper wire 150 mm (6 inch) long. Crimp a Deutsch terminal to both ends of the wire.
Monitor the "Active Diagnostic Code" screen before installing the jumper wire and after installing the jumper wire.
Install the jumper on the engine harness connector. Install one end of the jumper at the sensor signal (terminal 1). Install the other end of the jumper at the common connection for the engine temperature sensor (terminal 2). Wait at least 15 seconds for activation of the short circuit diagnostic code.Expected Result:A short circuit diagnostic code is active when the jumper is i