BREATHER 2Y9455 - Caterpillar

the following diagnostic codes:
41-3
41-4
262-3
262-4
460-21
1785-21
2131-3
2131-4
3031-21Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Remove the electrical power from the ECM. Expected Result:No diagnostic codes are active or logged.Results:
OK - No diagnostic codes are active or logged.Repair: There does not appear to be an electrical problem with the sensor supply at this time. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
41-3 or 41-4 Active or Logged - Either the 41-3 or 41-4 diagnostic code is active or logged at this time. There is an electrical problem with the digital sensor supply. Proceed to Test Step 6.
460-21, 1785-21, or 3031-21 Logged - A -21 diagnostic code is logged at this time. The analog supply is not reaching the sensor or there is a problem with the sensor. Proceed to Test Step 3.
262-3 or 262-4 Active or Logged - Either the 262-3 or 262-4 diagnostic code is active or logged at this time. There is an electrical problem with the analog sensor supply. Proceed to Test Step 4.
2131-3 or 2131-4 Active or Logged - Either the 2131-3 or 2131-4 diagnostic code is active or logged at this time. There is an electrical problem with the analog sensor supply. Proceed to Test Step 4.Test Step 3. Check the Supply Voltage at the Sensor Connector
Disconnect the harness connectors for the following sensors:
Fuel pressure sensor (filtered fuel pressure)
Intake manifold pressure sensor
Restore the electrical power to the ECM. Note: Be sure to wiggle the harness during the following measurements in order to reveal an intermittent condition.
Measure the voltage between terminals 1 and 2 at the appropriate sensor connector.
Remove the electrical power from the ECM.
Connect all of the sensors. Expected Result:Each voltage measurement is 5.0 0.2 VDC.Results:
OK - Each voltage measurement is 5.0 0.2 VDC.Repair: The analog supply is reaching the sensor connector. There may be a problem with the sensor. Perform the following procedure:
Clear all diagnostic codes.
Run the engine. Allow the engine to warm up. Check if the code has been logged again. If the code becomes active or logged, the sensor is faulty. Replace the sensor. Verify that the repair eliminates the original problem.If the code does not become active or logged, there may be an intermittent problem in the harness or in a connector. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct troubleshooting procedure.STOP
Not OK - At least one voltage measurement is not 5.0 0.2 VDC. There is a problem with the harness wiring or with the ECM. Proceed to Test Step 5.Test Step 4. Disconnect the Analog Sensors While You Check for Active Diagnostic Codes
Restore the electrical power to the ECM.
Monitor the active diagnostic code screen on Cat ET while you disconnect each 5 V sensor at the sensor connector. Check for an active 262-3, 262-4, 2131-3, or 2131-4. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Disconnect the following sensors one at a time:
Atmospheric pressure sensor
Buffer