0323263 JOHNSON PLATE, Exhaust cover

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Schematic for the digital sensor supply
The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.
Test Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
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Left side engine view (typical example) (1) J1/P1 ECM connector
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Left side engine view (typical example) (2) P61 Customer connector
Thoroughly inspect connectors (1) and (2). Inspect the connectors for each digital sensor. Refer to Troubleshooting, "Electrical Connectors - Inspect".
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P1 ECM connector (P1-3) Analog sensor return (P1-4) +8 V Digital supply (P1-5) Digital return (P1-46) Coolant level (P1-68) Auxiliary temperature
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J61 and P61 customer connectors (8) +8 V Digital supply (9) Digital return
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the digital sensor supply.
Check the allen head screw on the ECM connectors and the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for abrasions and for pinch points from the battery to the ECM.Expected Result:All 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 connectors and wiring are okay. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.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 2. Check for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
Turn the keyswitch to the ON position.
Observe the active diagnostic code screen on Cat ET. Wait at least 15 seconds so that any codes may become active. Look for these codes:
263-03
263-04 Expected Result:One of the above diagnostic codes is active:Results:
Active 263-03 code - A 263-03 diagnostic code is active. Proceed to Test Step 3.
Active 263-03 code - A 263-04 diagnostic code is active. Proceed to Test Step 4.
No active codes - None of the above codes are active.Repair: If any of the above codes are logged and the engine is not running properly, refer to Troubleshooting, "Troubleshooting Without a Diagnostic Code".If the engine is running properly at this time, there may be an intermittent problem in a harness that is causing the codes to be logged. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOPTest Step 3. Check the Voltage on the +8 V Supply Wire
Turn the keyswitch to the OFF position.
Disconnect all of the following digital sensors at the sensor connector:
Coolant level sensor J800/P800
Auxiliary temperature sensor J142/P142
Turn the keyswitch to the ON position.
Measure the voltage between terminal A and terminal B at the sensor connectors.Expected Result:The voltage is 8.0 0.4 VDC.Results:
OK - Each voltage measurement is 8.0 0.4 VDC.Repair: Connect all of the sensor connectors. Clear all diagnostic codes. Check for active diagnostic codes. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - At least one voltage measurement is not 8.0 0.4 VDC. There is a problem with the wiring or with the ECM. Proceed to Test Step 5.Test Step 4. Disconnect the +8 V Digital Sensors and Check for Active Diagnostic Codes
Disconnect the following sensors one at a time:
Engine coolant level
Auxiliary temperature
Wait for 15 seconds after you disconnect each sensor. Check if the 263-04 diagnostic code has deactivated.Expected Result:The 263-04 diagnostic code deactivates when a particular sensor is disconnected.Results:
OK - The 263-04 diagnostic code deactivates when a particular sensor is disconnected.Repair: Connect the suspect sensor. If the diagnostic code returns, replace the sensor.Connect all of the connectors. Verify that the problem is resolved.STOP
Not OK - The 263-04 diagnostic code remains after the sensors are disconnected. Leave the sensors disconnected. Proceed to Test Step 5.Test Step 5. Check the +8 V Supply Wire for a Short Circuit
Turn the keyswitch to the OFF position.
Disconnect the J1/P1 and J2/P2 ECM connectors.
Verify that the digital sensors are disconnected.Note: Wiggle the harness during the following measurements in order to reveal any intermittent short condition.
Measure the resistance between P1-4 (+8 V digital supply) and the remaining terminals on the P1 and P2 connectors.
Measure the resistance between P1-4 (+8 V digital supply) and the engine ground.