CAP 6B3226 - Caterpillar

Use this procedure to troubleshoot the electrical system if a problem is suspected with the CAN data link . Also use this procedure if a diagnostic code in Table 1 is active or easily repeated.
Table 1
J1939 Code and Description CDL Code and Description Comments
3216-11
Aftertreatment #1 Intake NOx : Other Failure Mode 3655-11
Aftertreatment #1 Intake NOx : Other Failure Mode The aftertreatment intake NOx sensor heater cannot generate enough heat or the power supply is intermittent.
3216-12
Aftertreatment #1 Intake NOx : Failure 3655-12
Aftertreatment #1 Intake NOx : Failure A failed aftertreatment intake NOx sensor has been detected.
3226-11
Aftertreatment #1 Outlet NOx : Other Failure Mode 3609-11
Aftertreatment #1 Outlet NOx : Other Failure Mode The aftertreatment outlet NOx sensor heater cannot generate enough heat or the power supply is intermittent.
3226-12
Aftertreatment #1 Outlet NOx : Failure 3609-12
Aftertreatment #1 Outlet NOx : Failure A failed aftertreatment outlet NOx sensor has been detected.
3360-12
Aftertreatment 1 Diesel Exhaust Fluid Controller : Failure 3820-12
Aftertreatment 1 Diesel Exhaust Fluid Controller : Failure A Diesel Exhaust Fluid Controller (DCU) has been flashed or a failed DCU has been detected.
3516–2
Aftertreatment #1 DEF Concentration: Erratic, Intermittent, or Incorrect 3100–2
Aftertreatment #1 DEF Concentration: Erratic, Intermittent, or Incorrect The DEF quality sensor is unable to read the DEF concentration due to an optical path obstruction.
3516–12
Aftertreatment #1 DEF Concentration: Failure 3100–12
Aftertreatment #1 DEF Concentration: Failure A failed DEF Quality Sensor has been detected Note: Turn the keyswitch to the OFF position before connecting or disconnecting these components.If the Caterpillar Electronic Technician (ET) will not communicate with the ECM, refer to Troubleshooting, "Electronic Service Tool Does Not Communicate" before you begin this procedure. The procedure verifies that electrical power is being supplied to the ECM and to the service tool connector.The data links are used to communicate information between the engine ECM and other control modules that are a part of the application. Cat ET also communicates with the ECM via the data links.The service tool connector contains connections for electrical power and for the data links.When the keyswitch is in the OFF position, Cat ET may communicate with the ECM. However, the communications may be disrupted and the communications may require frequent reconnection. In order to avoid this problem, place the keyswitch in the ON position when Cat ET is being used.Cat ET may display the following error message:"The version of the ECM is not recognized and the integrity of the changed parameters and displayed data is not guaranteed."This message indicates that one of the following conditions exist:
The flash file in the ECM is newer than the version of Cat ET.
The latest version of Cat ET has not been installed.
Illustration 1 g06156053Note: The DEF Quality Sensor is only available on 2017models or later.
Table 2
Troubleshooting Test Steps Values Results
1. Check the Connectors
A. Turn the keyswitch to ON.
B. Connect to the "Engine #1 Aftertreatment Controller" using Cat ET.
C. Record all active and logged codes.
D. Turn the keyswitch to OFF.
E. Allow the system to completely power down before disconnecting connectors.
F. Thoroughly inspect the connectors that are associated with the