C7 and C9 On-Highway Engines Caterpillar

The Engine Control Module (ECM) monitors the temperature at the intake of the Diesel Particulate Filter (DPF) and at the outlet of the DPF. The ECM activates the applicable code when the conditions are met.

Table 1

Diagnostic Trouble Codes for the Intake of the DPF
J1939 Code	Description	Information that Relates to the Code
3242-16	Diesel Particulate Filter Intake Gas Temperature (bank 1) : High - Moderate Severity (2)	The temperature at the intake of the DPF exceeded 750 °C (1380 °F). Active regeneration is immediately disabled. Engine power is derated. The code is logged.
3276-16	Diesel Particulate Filter Intake Gas Temperature (bank 2) : High - Moderate Severity (2)
Follow the troubleshooting procedure in order to identify the root cause of the problem.

Table 2

Diagnostic Trouble Codes for the Outlet of the DPF
J1939 Code	Description	Information that Relates to the Code
3246-15	Diesel Particulate Filter Outlet Gas Temperature (bank 1) : High - Least Severe (1)	The temperature at the outlet of the DPF exceeded 750 °C (1380 °F). Active regeneration is immediately disabled. Engine power is derated. The code is logged. These codes are usually caused by excessive fuel or oil in the DPF.
3280-15	Diesel Particulate Filter Outlet Gas Temperature (bank 2) : High - Least Severe (1)
3246-16	Diesel Particulate Filter Outlet Gas Temperature (bank 1) : High - Moderate Severity (2)	The temperature at the outlet of the DPF exceeded 800 °C (1470 °F). Active regeneration is immediately disabled. The Clean Gas Induction System (CGI) is turned off. Engine power is derated. The code is logged. These codes are usually caused by excessive fuel or oil in the DPF.
3280-16	Diesel Particulate Filter Outlet Gas Temperature (bank 2) : High - Moderate Severity (2)
Follow the troubleshooting procedure in order to identify the root cause of the problem.

Troubleshooting Procedure

1. If you are troubleshooting a 3246-16 code or a 3280-16 code, the outlet of the DPF must be inspected. Perform the following procedure in order to inspect the DPF. For all other codes, proceed to the next test step.

   1. Remove the outlet section from the DPF. Inspect the outlet face of the DPF. Contact your local technical communicator for Caterpillar on-highway truck engines for assistance in determining if the DPF must be replaced.

      If the DPF is OK, continue with this troubleshooting procedure in order to determine the cause of the very high outlet temperature.

      If the DPF must be replaced, continue with this troubleshooting procedure in order to determine the cause of the very high outlet temperature. Then, replace the DPF. Provide the serial numbers of both of the diesel particulate filters to your local technical communicator for Caterpillar on-highway truck engines.

2. If the vehicle is equipped with an ARD disable switch, verify that the switch is not disabling the ARD. Refer to the vehicle's service manual in order to determine the proper operation of the switch.

3. Troubleshoot any diagnostic codes that relate to the following systems or conditions:
   • Low boost

   • ARD

   • Clean Gas Induction System (CGI)

   Troubleshoot the systems in the order that is listed above if there are diagnostic codes for more than one of the systems.

4. If the ARD disable switch was not disabling the ARD and there are no problems with the systems that are listed above, perform this test step. If the switch was disabling the ARD or there was a problem with a system that is listed above, continue to the next test step.

   1. Remove the inlet section from the DPF. Inspect the inside of the inlet section and the front face of the DPF. Look for oil and for excessive soot.

      The presence of a small amount of soot is a normal condition. Contact your local technical communicator for Caterpillar on-highway truck engines if you suspect that the amount of soot is excessive. Continue with this procedure after you have received guidance from the technical communicator.

      If oil is found, inspect the outlet of the turbocharger. Contact your local technical communicator for Caterpillar on-highway truck engines if oil is found. Continue with this procedure after you have received guidance from the technical communicator. Clean the oil from the inside of the inlet section of the DPF and the front face of the DPF. Assemble the DPF. Use Cat ET to disable the ARD. Set the value of the "Data Link ARD Disable Status" configuration parameter to "Disabled" in order to disable the ARD. Run the engine at 1400 rpm for 15 minutes. Then, proceed to the next test step.

      If no oil is found, leave the inlet section disconnected from the DPF. Use Cat ET to disable the ARD. Set the value of the "Data Link ARD Disable Status" configuration parameter to "Disabled" in order to disable the ARD.

      Perform a manual cylinder cutout test. Manually cut out each cylinder while the exhaust is monitored. Look for the smoke to disappear as each cylinder is cut out. Replace any injectors that cause the engine to smoke and run rough when the cylinder is not cut out. Clean the inside of the inlet section of the DPF and the front face of the DPF. Assemble the DPF. Run the engine at 1400 rpm for 15 minutes.

      Set the value of the "Data Link ARD Disable Status" configuration parameter to "Not Disabled" in order to enable the ARD. Then, proceed to the next test step.

5. Use Cat ET to perform a stationary regeneration. Look for a 310 diagnostic code after the stationary regeneration is complete.

   Return the engine to service if there is a 310 diagnostic code at the end of the stationary regeneration.

   Perform the following procedure if a 310 diagnostic code is not activated at the end of the stationary regeneration:

   1. Increase the engine speed to 1400 rpm.

   2. Use Cat ET to determine the differential pressure of the DPF while the engine speed is 1400 rpm. The parameter is "Diesel Particulate Trap #1 Differential Pressure". You may need to create a new group in order to view this parameter.

   3. Return the engine speed to idle.

      Replace the DPF if the differential pressure of the DPF is greater than 15.0 kPa (2.1 psi) during engine operation at 1400 rpm.