BEARING-SLEEVE 1969988 - Caterpillar

System Operation Description:Use this procedure to troubleshoot any suspect problems with the +8 V digital supply.This procedure covers the following diagnostic codes:
041-03 8 Volt DC Supply short to +batt
041-04 8 Volt DC Supply short to groundThe Electronic Control Module (ECM) creates a regulated voltage of 5.0 0.2 VDC that is supplied to terminal A of the harness connector for the coolant level sensor.A +8 V diagnostic code is probably caused by a short circuit to ground or a short circuit to another voltage source in the harness. The next likely cause is a problem with the sensor. The least likely cause is a problem with the ECM.
Illustration 1 g01136745
Schematic for the 8 volt supplyTest Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Illustration 2 g01134630
Engine components for the 8 volt supply (1) J2/P2 ECM connector (2) Coolant level sensor
Thoroughly inspect connector (1). Inspect the connector for sensor (3). Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01136747
P2 terminals that are associated with the 8 volt supply (P2-14) Return (P2-29) +8 VDC
Illustration 4 g01132478
Harness connector for the coolant level sensor (A) +8 VDC (B) Return
Perform a 45 N (10 lb) pull test on each of the wires in the circuit for the digital sensor supply.
Check the allen head screw on each ECM 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 sensor 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 with the connectors 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.STOPTest Step 2. Check for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (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:One of the following diagnostic codes is active:
041-03
041-04 Results:
OK - A 041-03 diagnostic code is active. Proceed to Test Step 3.
OK - A 041-04 diagnostic code is active. Proceed to Test Step 4.
Not OK - No diagnostic code for the digital supply is active. Proceed to Test Step 3 in order to verify that the sensor is receiving the correct supply voltage.Test Step 3. Check for Supply Voltage at the Sensor's Connector
Turn the keyswitch to the OFF position.
Disconnect the harness connector for the coolant level sensor.
Turn the keyswitch to the ON position.
Measure the voltage between terminals A and B at the harness connector.Expected Result:The voltage is 8.0 0.4 VDC.Results:
OK - The voltage is 8.0 0.4 VDC. The voltage