KIT- 4951630 - Caterpillar

Use this procedure to troubleshoot the electrical system if a problem is suspected with the NOX sensor group. Also, use this procedure if one of the diagnostic codes or the event code in Table 1 is active or easily repeated.
Table 1
J1939 Code and Description Comments
3221-2
Aftertreatment #1 Intake Wide-Range O2 Reading Stable : Erratic, Intermittent, or Incorrect The catalyst intake oxygen sensor has detected an internal problem which results in data that is unstable and/or not in the correct format.
Replace the oxygen sensor
3221-3
Aftertreatment #1 Intake Wide-Range O2 Reading Stable : Voltage Above Normal The catalyst intake oxygen sensor has detected high supply voltage at the sensor.
The code is logged.
3221-4
Aftertreatment #1 Intake Wide-Range O2 Reading Stable : Voltage Below Normal The catalyst intake oxygen sensor has detected low supply voltage at the sensor.
The code is logged.
3221-12
Aftertreatment #1 Intake Wide-Range O2 Reading Stable : Failure The catalyst intake oxygen sensor has detected an internal problem with the sensor.
Replace the oxygen sensor
3221-14
Aftertreatment #1 Intake Wide-Range O2 Reading Stable : Special Instruction The catalyst intake oxygen sensor has detected an internal problem with the sensor heating element. The sensor was unable to reach operating temperatures within the predetermined amount of time.
If a CAN Data Link -9 diagnostic is active or logged against the NOx sensor, troubleshoot the -9 diagnostic before replacing the sensor.
If there is no -9 diagnostic, then replace the oxygen sensor.
3222-12
Aftertreatment #1 Intake Gas Sensor Heater Preliminary FMI : Failure The catalyst intake oxygen sensor has detected an internal problem with the sensor heating element.
Replace the oxygen sensor
3231-2
Aftertreatment #1 Outlet Wide-Range O2 Reading Stable : Erratic, Intermittent, or Incorrect The catalyst outlet oxygen sensor has detected an internal problem which results in data that is unstable and/or not in the correct format.
Replace the oxygen sensor
3231-3
Aftertreatment #1 Outlet Wide-Range O2 Reading Stable : Voltage Above Normal The catalyst outlet oxygen sensor has detected high supply voltage at the sensor.
The code is logged.
3231-4
Aftertreatment #1 Outlet Wide-Range O2 Reading Stable : Voltage Below Normal The catalyst outlet oxygen sensor has detected low supply voltage at the sensor.
The code is logged.
3231-12
Aftertreatment #1 Outlet Wide-Range O2 Reading Stable : Failure The catalyst outlet oxygen sensor has detected an internal problem with the sensor.
Replace the oxygen sensor
3231-14
Aftertreatment #1 Outlet Wide-Range O2 Reading Stable : Special Instruction The catalyst outlet oxygen sensor has detected an internal problem with the sensor heating element. The sensor was unable to reach operating temperatures within the predetermined amount of time.
If a CAN Data Link -9 diagnostic is active or logged against the NOx sensor, troubleshoot the -9 diagnostic before replacing the sensor.
If there is no -9 diagnostic, then replace the oxygen sensor.
3232-12
Aftertreatment #1 Outlet Gas Sensor Heater Preliminary FMI : Failure The catalyst outlet oxygen sensor has detected an internal problem with the sensor heating element.
Replace the oxygen sensor. The oxygen sensors are used to monitor the emission level of the engine exhaust by measuring the oxygen concentration in the exhaust stream. The ECM utilizes the signal from the oxygen sensors to