19291A 3 Mercury BEARING CARRIER ASSEMBLY

Illustration 1 g01075330
Schematic of the circuit for the oxygen sensor and the oxygen buffer
Test Step 1. Inspect the Electrical Connectors and Wiring
During operation, the oxygen sensor may reach temperatures that exceed 700 °C (1292 °F). Severe personal injury and property damage will result from contact with a hot oxygen sensor.Do not touch the sensor during engine operation, calibration, or testing. Allow the sensor to cool before moving the sensor. Wear gloves that resist heat. Do not place the sensor on or near any flammable material or any surface that can be damaged by high temperatures.
Illustration 2 g01075275
Terminal box
(1) ECM connectors J2/P2
(2) 16 amp circuit breaker
(3) J10/P10 connector for the harness from the oxygen buffer
Set the engine control to the OFF/RESET mode. Switch 16 amp circuit breaker (2) to the OFF position. Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
Thoroughly inspect the following connections:
J2/P2 connectors
J10/P10 connectors on the terminal box
Check the torque of the allen head screw for the ECM connector. The proper torque is 6 1 N m (55 9 lb in).
Illustration 3 g01075280
Harness side of the P2 connector
(P2-13) +24 VDC for the buffer
(P2-23) Return
(P2-53) Return
(P2-67) Oxygen signal (PWM)
Illustration 4 g00894829
Harness side of the P10 connector
(P10-H) Return
(P10-K) +24 VDC for the buffer
(P10-L) Return
(P10-M) Oxygen signal (PWM)
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the oxygen sensor.
Illustration 5 g01075292
(1) Oxygen sensor
(2) Connectors for the oxygen sensor
(3) Oxygen buffer
(4) P651 connector for the harness from the terminal box
(5) P652 connector for the harness to the oxygen sensor
Check the harness and wiring for abrasion and for pinch points from the oxygen sensor to the ECM. Expected Result:All of the connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - All of the connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points. The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - At least one of the connectors, pins, or sockets are not connected properly. At least one of the connectors and/or the wiring has corrosion, abrasion, and/or pinch points.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. Measure the Supply Voltage for the Heater at the Harness Connector for the Oxygen Sensor
Connect Cat ET to the service tool connector on the terminal box. Refer to Troubleshooting, "Electronic Service Tools".
Disconnect the oxygen sensor from the engine harness.
Switch the 16 amp circuit breaker ON. Set the engine control to the STOP mode.
Access the "Diagnostic Override" screen of Cat ET. Select "Diagnostics/Diagnostic Tests/Override Parameters".
Select "Change" in the lower left corner of the screen.
Select a "New Value" of "On" and then select "OK". The oxygen buffer is now ON. The status of the "Oxygen Sensor Override" should change to "On". Wait for 65 seconds.Note: After you exit the "Override Parameters" screen, the status of the "Oxygen Sensor Override" is automatically changed to "OFF" when the engine control is not in the START mode.