PLUG 1993109 - Caterpillar

Illustration 1 g00904082
SchematicTest Step 1. Inspect Electrical Connectors and Wiring
Illustration 2 g00904083
ECM connectors (wire side)
Thoroughly inspect the J1/P1 ECM connector, the J2/P2 ECM connector, and the connectors for each pressure sensor.Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the +5 V sensor supply.Refer to Illustration 2.
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 abrasion and pinch points from the sensors back to the ECM.Expected Result:All connectors, pins and sockets should be completely coupled and/or inserted and the harness and wiring should be free of corrosion, abrasion or pinch points.Results:
OK - Proceed to Test Step 2.
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. Stop.Test Step 2. Check for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (Cat ET) to the service tool connector.
Turn the keyswitch to the ON position.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes.Note: Wait at least 15 seconds in order for the diagnostic codes to become active.Expected Result:Note the condition of the following codes:
262-03 5 Volt Sensor Supply short to +batt
262-04 5 Volt Sensor Supply short to groundResults:
262-03 Active - Proceed to Test Step 3.
262-04 Active - Proceed to Test Step 4.
262-03 or 262-04 Logged ONLY - Proceed to Test Step 6.
Not Active or Logged - The +5 V supply is operating correctly at this time. Stop.Test Step 3. Short the Output at the ECM
Turn the keyswitch to the OFF position.
Remove the J844-GY wire from P1:2 (Engine Pressure Sensor +5V), the G828-WH wire from P2:2 (Engine Pressure Sensor +5V), and the G826-BR from P2:41 (Engine Pressure Sensor +5V).
Install a jumper wire between P1:2 (Engine Pressure Sensor +5V) and the ECM ground strap. Install another jumper wire between P2:2 (Engine Pressure Sensor +5V) and the ECM ground strap. Install another jumper wire between P2:41 (Engine Pressure Sensor +5V)and the ECM ground strap.
Turn the keyswitch to the ON position.
Check for active diagnostic codes on Cat ET.Expected Result:The 262-03 5 Volt Sensor Supply short to +batt should change to a 262-04 5 Volt Sensor Supply short to ground when the jumper wire is installed.Results:
OK - The ECM is responding correctly. Proceed to Test Step 5.
Not OK - The ECM is not responding correctly.Repair: Verify your results before replacing the ECM. Refer to Troubleshooting, "Replacing the ECM" before you replace the ECM. Stop.Test Step 4. Open the Output at the ECM
Turn the keyswitch to the OFF position.
Remove the J844-GY wire from P1:2 (Engine Pressure Sensor +5V), the G828-WH wire from P2:2 (Engine Pressure Sensor +5V), and the G826-BR from P2:41 (Engine Pressure Sensor +5V).
Turn the keyswitch to the ON position.
Check for active diagnostic codes on Cat ET.
Reinstall the