12805 4 Mercury LEVER-FAST IDLE

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(1) 54-pin connector for the ITSM (2) Connector for the thermocoupleTest Step 1. Inspect the Electrical Connectors and Wiring
Turn the engine control switch to the OFF/RESET position.
Thoroughly inspect the connectors for the suspect thermocouple:
54-pin connector for the ITSM
Connectors for the thermocouple
Check the harness and wiring for abrasion and pinch points from the suspect thermocouple to the ITSM.Expected Result:All of the connectors and terminals are connected properly. The connectors and the wiring are free of corrosion, abrasion and pinch points.Results:
OK - The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - The components are not in good condition and/or at least one connection is improper.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 2. Verify the Active Diagnostic Code
Turn the engine control switch to the STOP position.
Observe the "Active Diagnostic" screen on the electronic service tool. Wait at least 30 seconds so that any codes may become activated.Expected Result:None of the above codes are active.Results:
No active codes - The problem seems to be resolved. There are no active codes. The thermocouples are operating correctly at this time.Repair: The initial diagnostic code was probably caused by a poor electrical connection in one of the harness connectors. Resume normal operation. Stop.
Active short to +batt (FMI 03) - There is an active short to +batt diagnostic code. Proceed to Test Step 3.
Active short to ground (FMI 04) - There is an active short to ground diagnostic code. Proceed to Test Step 3.
Active open circuit (FMI 05) - There is an active open circuit diagnostic code. Proceed to Test Step 4.Test Step 3. Disconnect the Sensor in Order to Create an Open Circuit
Turn the engine control switch to the OFF/RESET position.
Disconnect the thermocouple that has the short circuit diagnostic code.
Turn the engine control switch to the STOP position.
Observe the "Active Diagnostic" screen on the Caterpillar Electronic Technician (ET). Wait at least 30 seconds so that any codes may become activated.Expected Result:An open circuit diagnostic code was generated for the suspect thermocouple.Results:
OK - Before the suspect thermocouple was disconnected, there was an active "short circuit" diagnostic code. After the thermocouple was disconnected, there was an active "open circuit" diagnostic code.Repair: Reconnect the thermocouple. If the active "short circuit" diagnostic code reoccurs, replace the thermocouple. Verify that the problem is resolved. Lubricate the threads of the new thermocouple with a nickel based, high temperature anti-seize compound. Tighten the new thermocouple to 25 5 N m (18 4 lb ft). Stop.
Not OK - Before the suspect thermocouple was disconnected, there was an active "short circuit" diagnostic code. After the thermocouple was disconnected, the active "short circuit" diagnostic code remained. Proceed to Test Step 5.Test Step 4. Create a Short Circuit at the Connector for the Thermocouple
Turn the engine control switch to the STOP position.
Fabricate a jumper wire with the appropriate terminals on each end.Note: Observe the "Active Diagnostic" screen on the Cat ET before installing the jumper wire and after installing the jumper wire.
Insert one end of the jumper wire into the positive socket of the harness connector for the suspect thermocouple. Connect the other end of the