AUXILIARY WATER PUMP ASSEMBLY 3N6937 - Caterpillar

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) Injection actuation pressure sensor (2) Boost pressure sensor (3) Fuel pressure sensor (4) Engine oil pressure sensor (5) J2/P2 ECM connector
Thoroughly inspect the connectors for pressure sensors (1), (2), (3), and (4). Also, thoroughly inspect connector (5). Refer to Troubleshooting, "Electrical Connectors - Inspect".
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P1 ECM connector (P1-2) +5 V sensor supply (P1-3) Sensor return (P1-32) Engine cooling fan speed sensor
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P2 ECM connector (P2-2) +5 V sensor supply (P2-3) Sensor return (P2-16) Fuel pressure (P2-24) Engine oil pressure (P2-27) Injection actuation pressure (P2-40) Boost pressure (P2-41) +5 V sensor supply (P2-42) Sensor return
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Sensor connector (A) +5 V supply (B) Sensor return (C) Signal
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit.
Check the allen head screw for each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for abrasion and for pinch points from the pressure sensors back 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 harness and connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with 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 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" screen on Cat ET. Wait at least 30 seconds so that any codes may become active. Look for these codes:
262-03
262-04
Determine if the problem is related to a -03 diagnostic code or to a -04 diagnostic code.Expected Result:No diagnostic codes are active.Results:
OK - No diagnostic 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".STOP
Active -03 code - A -03 diagnostic code is active. Proceed to Test Step 3.
Active -04 code - A -04 diagnostic code is active. Proceed to Test Step 4.Test Step 3. Check the Supply Voltage at the Sensor Connector
Turn the keyswitch to the OFF position.
Disconnect the harness connectors for the following sensors:
Boost pressure sensor
Injection actuation pressure sensor
Fuel pressure sensor
Engine oil pressure sensor
Engine cooling fan speed sensor
Turn the keyswitch to the ON position.Note: Be sure to wiggle the harness during the following measurements in order to reveal an intermittent condition.
Measure