SEAL 2W2072 - Caterpillar

Most electrical faults are caused by poor connections. The following procedure will help in detecting faults with connectors and with wiring. If a fault is found, correct the condition and verify that the fault is resolved.Intermittent electrical faults are sometimes resolved by disconnecting and reconnecting connectors. Check for diagnostic codes immediately before disconnecting a connector. Also check for diagnostic codes after reconnecting the connector. If the status of a diagnostic code is changed due to disconnecting and reconnecting a connector, there are several possible reasons. The likely reasons are loose terminals, improperly crimped terminals, moisture, corrosion, and inadequate mating of a connection.Follow these guidelines:
Always use a 151-6320 Removal Tool to remove the pins from the P1/P2 connectors.
Always use a 1U-5804 Crimp Tool to service Deutsch HD and DT connectors. Never solder the terminals onto the wires. Refer to Special Instruction, SEHS9615, "Servicing Deutsch HD and DT Style Connectors".
Always use a 147-6456 Removal Tool to remove wedges from DT connectors. Never use a screwdriver to pry a wedge from a connector.
Always use a 1U-5804 Crimp Tool to service AMP seal connectors. Refer to Special Instruction, REHS2556, "AMPSEAL 16 Connector System".
Refer to Troubleshooting, "ECM Harness Connector Terminals" to service the connectors for the Electronic Control Module (ECM).
Always use a breakout harness for a voltmeter probe or a test light. Never break the insulation of a wire to access a circuit for measurements.
If a wire is cut, always install a new terminal for the repair.
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.
Illustration 1 g01883953
Leaking seal at the connector (typical example)
Some components are not shown for clarity.
(1) Wire pulled to one side. Note the gap between the seal and the wire.
Illustration 2 g01131276
Diagram for the installation of a connector plug (typical example)
(1) ECM connector
(2) Correctly inserted plug
(3) Incorrectly inserted plug
Illustration 3 g01131019
Seal for a three-pin connector (typical example)
Illustration 4 g02686257
(1) Seal for ECM connector
Table 1
Troubleshooting Test Steps Values Results
1. Check Connectors for Moisture and Corrosion
A. Inspect all the harnesses. Ensure that the routing of the wiring harness allows the wires to enter the face of each connector at a perpendicular angle. Otherwise, the wire will deform the seal bore. This situation can create a path for the entrance of moisture. Verify that the seals for the wires are sealing correctly.
B. Ensure that the sealing plugs are in place. If any of the plugs are missing, replace the plug. Ensure that the plugs are inserted correctly into the connector. Refer to Illustration 2.
C. Disconnect the suspect connector and inspect the connector seal. Ensure that the seal is in good condition. If necessary, replace the connector.
D. Thoroughly inspect the connectors for evidence of moisture entry.
Note: Some minor seal abrasion on connector seals is normal. Minor seal abrasion will not allow the entry of moisture.
If moisture or corrosion is evident in the connector,