| 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. NOTE: 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. NOTE: 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 adjust the air/fuel ratio. This strategy ensures that the engine burns the fuel efficiently. Two oxygen sensors are used for this application. One oxygen sensor is mounted at the catalyst inlet. The other oxygen sensor is mounted in the output flange of the catalytic converter. Each sensor circuit consists of an oxygen sensor and a voltage converter that is used to power both sensor circuits. The sensors generate a signal that is proportional to the concentration of oxygen which is relayed to the engine ECM via the CAN data link. This type of sensor is a wideband oxygen sensor that can self-diagnose internal problems. The sensor will notify the engine ECM of an issue when detected. Some diagnostics reported from the Oxygen sensor will indicate that the sensor has failed and will need replaced. If repeat failures occur, check the sensor installation for any contributing factors such as exposure to moisture or wiring harness high heat exposure
The oxygen sensor exposure limits should not exceed the following:
- Controller ambient temperature range -40 to 105 C
- Grommet temperature greater than 240 C
- Cable temperature greater than 200 C
Each oxygen sensor utilizes a heating element to heat the sensing element of the sensor.
Note: The sensors have an operating range of
To operate, the oxygen sensor requires a supply voltage in the range of 10-18 Volts DC.
A voltage converter converts the 24 VDC from the battery to 12 VDC that is used to power each of the oxygen sensors.
The voltage convertor is enabled and disabled by a 24VDC output from the engine ECM.
When the voltage convertor is disabled, the 12 VDC to the oxygen sensors will be turned off.
If either oxygen sensor looses the 12 VDC supply when the ECM is enabling the voltage converter, the ECM will detect the loss of communication and issue a -9 abnormal update rate CAN data link fault for the component.
If a -9 abnormal update rate diagnostic is active for the oxygen sensor, ensure the following are true:
- 24 VDC at the voltage converter terminal 2 when the ECM is enabling the converter.
- 12 VDC at the oxygen sensor terminal 1 when the ECM is enabling the converter.
Refer to Troubleshooting , Data Link - Test for additional information on -9 codes.
| |
| Illustration 1 | g06199304 |
|
For the complete circuit details, refer to the full schematic. | |
| Troubleshooting Test Steps | Values | Results |
|---|---|---|
1. Inspect the Electrical Connectors and the Wiring A. Turn the main disconnect switch to the OFF position. B. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information. C. Perform a D. Check the harness for abrasions and pinch points. |
Connectors and Wiring |
Result: The connectors and wiring appear to be OK. Proceed to Test Step 2. Result: There is a problem with the connectors and/or wiring. Repair: Repair or replace the connectors or wiring. Ensure that all the seals are properly in place and ensure that the connectors are coupled. If the problem is not resolved, proceed to Test Step 2. |
2. Check for Codes A. Connect Cat® Electronic Technician (ET) to the service tool connector. B. Determine if a code is active or logged. |
Codes listed in Cat ET |
NOTE: If a CAN Data Link -9 diagnostic is active or logged against the oxygen sensor, troubleshoot the -9 diagnostic before performing this procedure. Result : There is a code with FMI -3 Proceed to step 3. Result : There is a code with FMI -4. Proceed to step 4. Result : There is a code with FMI -2, FMI -12, or an FMI -14. Repair : Replace the oxygen sensor group and verify that the code goes away. |
3. Check the 12 Volt Supply for the Oxygen Sensor at the Voltage Converter A. Disconnect the D-C4 connector from the oxygen sensor voltage converter. B. Turn the keyswitch to the ON position. C. Measure the DC voltage between the following voltage converter connector terminals: - Connector D-C4 terminal 5 - Connector D-C4 terminal 3 |
-3 code |
Result : The voltage at the voltage converter is less than 18 volts. Repair : Replace the voltage converter and verify that the code goes away. Result : The voltage at the voltage converter is greater than or equal to 18 volts. Repair : There is a short to a power source in the harness. Repair or replace the wiring harness. |
4. Check the Battery Supply Voltage at the Voltage Converter A. Install a 7X-1708 Multimeter Probe (RED) and a 7X-1709 Multimeter Probe (BLACK) onto the test leads of a multimeter. Note: Ensure that the multimeter probes are in good condition. Bent probes may contact other terminals inside the connector. B. Install the spoons into the following locations of the voltage converter connector D-C4. - Connector D-C4 terminal 1 - Connector D-C4 terminal 3 C. Turn the keyswitch to the ON position. D. Measure and observe the voltage at the voltage converter connector. |
-4 code |
Result : The battery voltage at the voltage converter is greater than 18 volts. Proceed to step 5. Result : The battery voltage at the voltage converter is less than 18 volts. Repair : Troubleshoot the battery supply circuit. |
5. Check the 12 Volt Supply for the Oxygen Sensor at the Voltage Converter A. Install the spoons into the following locations of the voltage converter connector D-C4. - Connector D-C4 terminal 5 - Connector D-C4 terminal 3 B. Turn the keyswitch to the ON position. C. If available, activate the Cat ET service override for the oxygen sensor power supply. If unavailable, start the engine and run in accordance with oxygen sensor power supply enablement conditions listed in the beginning of this procedure. D. Measure and observe the voltage at the voltage converter connector. |
-4 code |
Result : The voltage at the voltage converter connector is greater than 10 volts. Proceed to step 6. Result : The voltage at the voltage converter connector is less than 10 volts. Repair : Replace the voltage converter. |
6. Check the 12 Volt Supply for the Oxygen Sensor at the Oxygen Sensor A. Install the spoons into the following locations of the appropriate oxygen sensor connector for the code. - Connector terminal 1 - Connector terminal 2 B. Turn the keyswitch to the ON position. C. If available, activate the Cat ET service override for the oxygen sensor power supply. If unavailable, start the engine and run in accordance with oxygen sensor power supply enablement conditions listed in the beginning of this procedure. D. Measure and observe the voltage at the oxygen sensor connector. |
-4 code |
Result : The voltage at the oxygen sensor connector is greater than 10 volts. Repair : Replace the oxygen sensor. Result : The voltage at the oxygen sensor connector is less than 10 volts. There is a problem in the harness or connector. Repair : Repair or replace parts as necessary. |