HOSE AS 2315298 - Caterpillar

Table 1
Points to Check for Continuity    
P2-67 Oxygen signal (PWM)     P2-23 Return    
P2-67 Oxygen signal (PWM)     Ground strap for the ECM    
Expected Result:The wiring between terminals P2-67 and P2-23 has continuity. The wiring between terminals P2-67 and the ground strap has continuity.Results:
OK - The wiring between terminals P2-67 and P2-23 has continuity. The wiring between terminals P2-67 and the ground strap has continuity. Proceed to Test Step 5.
Not OK - At least one of the continuity checks is incorrect. There is a problem with the harness between the terminal box and the oxygen buffer.Repair: Repair the harness, when possible. Replace parts, if necessary.STOPTest Step 5. Isolate the Oxygen Signal and Check the Signal at the ECM
Restore the wiring to the original configuration. Connect all connectors.
Remove the wire from terminal location P2-67 at the ECM connector.
Use a multimeter that measures the duty cycle and the frequency of a signal. Connect one lead of the multimeter to the terminal that was removed from P2-67.
Insert a 7X-1710 Multimeter Probe along terminal P2-23 of the ECM P2 connector. Connect the other multimeter lead to the 7X-1710 Multimeter Probe .
Set the engine control to the Start/Run position.
Start the engine and run the engine. Engine speed must be present in order to activate diagnostic codes. 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". The override changes to "OFF" only when the engine control is not in the START position.
Measure the duty cycle and the frequency of the signal between the wire that was removed from terminal 67 and terminal P2-23.Expected Result:The duty cycle of the signal is between 20 and 90 percent.The frequency of the signal is between 375 and 625 Hz.Results:
OK - A valid oxygen signal is present at terminal P2-67.Repair: Perform the following steps:
Set the engine control to the OFF/RESET position.
Insert terminal 67 into the P2 connector. Pull on the wire in order to verify proper installation of the terminal.
Remove the 7X-1710 Multimeter Probe from terminal P2-23.
Set the engine control to the COOLDOWN/STOP position. Clear all of the logged diagnostic codes.
Turn on the oxygen buffer. Use Cat ET to check for logged 1087-03 and 1087-08 diagnostic codes.
If either of the codes are present, replace the ECM according to Troubleshooting, "Replacing the ECM".STOP
Not OK - A valid oxygen signal is not present at P2-67.Repair: Perform the following steps:
Set the engine control to the OFF/RESET position.
Insert terminal 67 into the P2 connector. Pull on the wire in order to verify proper installation of the terminal.
Remove the 7X-1710 Multimeter Probe from terminal P2-23.
Install an oxygen buffer that is known to be good.
Verify that the condition has been resolved. If