CONNECTOR AS 3C8251 - Caterpillar

Visually inspect the sensor assembly without removing the sensor assembly from the engine. Flanges (2) must be flush against engine (1) in order to ensure proper operation.Inspect bracket (3). Verify that the bracket allows the flanges to be flush against the engine.Verify that the bracket is not bent. If the bracket is bent or if an obstruction is preventing the sensor assembly from being installed correctly, the engine will not start.Note: The bracket cannot be replaced separately.
Remove the sensor assembly from the engine.
Illustration 3 g01142633
Sensor assembly (4) O-ring
Ensure that one O-ring (4) is installed on each sensor. Check the O-rings for damage. Replace the O-rings, if necessary.Results:
OK - The sensor assembly's components are OK.Repair: Perform the following procedure in order to properly install the sensor assembly:
Lubricate each O-ring with engine oil.
Fully seat the sensor assembly in the engine.Note: If the sensor assembly will not fully seat into the engine, replace the sensor assembly.
Tighten the bracket bolt.
Connect the sensor's electrical connectors. Verify that the connectors are latched on both sides.
Ensure that the harness is properly secured, and that the tie-wraps are placed in the correct location. Proceed to Test Step 3.
Not OK - At least one of the sensor assembly's components is not OK.Repair: Obtain a new sensor assembly. Perform the following procedure in order to properly install the sensor assembly:
Lubricate each O-ring with engine oil.
Fully seat the sensor assembly in the engine.Note: If the sensor assembly will not fully seat into the engine, replace the sensor assembly.
Tighten the bracket bolt.
Connect the sensor's electrical connectors. Verify that the connectors are latched on both sides.
Ensure that the harness is properly secured, and that the tie-wraps are placed in the correct location.Verify that the problem is resolved.STOPTest Step 3. Inspect the Electrical Connectors and the Wiring
Illustration 4 g01142629
Typical left side view (1) Connector for engine timing calibration (2) J2/P2 ECM connector (3) Connectors for the primary engine speed/timing sensor (4) Connectors for the secondary engine speed/timing sensor
Thoroughly inspect connectors (1), (2), (3), and (4). Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 5 g01144149
P2 terminations for the engine speed/timing sensors (P2-25) Primary engine speed/timing − (P2-26) TDC probe + (P2-35) Primary engine speed/timing + (P2-36) TDC probe − (P2-46) Secondary engine speed/timing + (P2-47) Secondary engine speed/timing −
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the engine speed/timing sensors.
Check the torque of the allen head screws for the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from each sensor back to the ECM.Expected Result:All of the 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 4.
Not OK - The connectors and/or wiring are not OK.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the seals