P200C

P200C-DIESEL PARTICULATE FILTER OVER TEMPERATURE - BANK 1







Theory of Operation

The Exhaust Temperature Sensors are used by the Engine Control Module (ECM) to monitor the engine exhaust temperatures in the after treatment system. The Exhaust Temperature Sensors are thermistors and change resistance based on the temperature being measured. The ECM provides a 5-Volt reference voltage to the sensor. The ECM monitors the voltage on the signal circuit and converts this to a temperature value. When the exhaust gas temperature is cold, the sensor or thermistor resistance is high. The ECM signal voltage only pulls down a small amount through the sensor to ground. Therefore, the ECM senses a high signal voltage or low temperature. When the exhaust gas temperature is hot, the sensor resistance is low. The signal voltage pulls down a large amount. Therefore, the ECM senses a low signal voltage, or a high temperature. The ECM will illuminate the MIL lamp immediately when the diagnostic runs and fails. Active regeneration of the after treatment particulate filter will be disabled. This DTC can only be cleared with a scan tool.

- When Monitored:
The diagnostic runs continuously when the engine is running.

- Set Condition:
The Engine Control Module (ECM) detects that the after treatment Diesel Particulate Filter outlet temperature is greater than a calibrated temperature for a calibrated period.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. OTHER DTCS
1. Ignition on, engine not running.
2. With the scan tool, read DTCs.

Are any fuel injector DTCs Active?

Yes

- Repair any fuel injector DTCs.

No

- Go To 2

2. BASE ENGINE FAILURE
1. Check for base engine failures.
2. Check for potential causes of excessive soot generation in the engine.

NOTE: Diagnose any other fault codes for the above items.

Was a base engine failure found?

Yes

- Replace the failed base engine failure component causing the high soot levels.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CYLINDER MISFIRE
1. Start the engine.
2. Allow the engine to idle.
3. With the scan tool, read the Misfire counter status.

Is an engine misfire detected?

Yes

- Determine the cause of the engine misfire. Use scan tool Cylinder Cutout Test to isolate a failed injector. Replace the failed injector if necessary. Inspect the after treatment system for possible damage.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 4

4. INJECTOR RETURN FLOW TEST
1. Injector Return Flow Test Perform the INJECTOR RETURN FLOW TEST.

Did the fuel injectors pass the test?

Yes

- Repair as necessary
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 5

5. EXHAUST TEMPERATURE
1. With the scan tool, read the Exhaust Temperature Sensors to determine the exhaust temperature.

Is the temperature reading above 225°F?

Yes

- Go To 6

No

- Go To 7

6. EXHAUST TEMPERATURE SENSOR 1/1 AND 1/3
1. Start the engine.
2. Raise the engine speed to 2500 RPM's for two minutes.

Do the temperature readings of Exhaust Temperature Sensor 1/1 and Exhaust Temperature Sensor 1/3 change in value at least 5°F?

Yes

- Go To 8

No

- Replace the Exhaust Temperature Sensor that did not change in value by at least 5°F or is not updating.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

7. EXHAUST TEMPERATURE SENSOR 1/1 AND 1/3
1. Start the engine and allow it to idle for 10 minutes.
2. With the scan tool, read the values of Exhaust Temperature Sensor 1/1 and Exhaust Temperature Sensor 1/3.

Do both temperature sensors read above 150°F and are the values of both temperature sensors updating?

Yes

- Go To 8

No

- Replace the Exhaust Temperature Sensor that is not above 150°F or is not updating on the scan tool.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

8. EXCESSIVE ENGINE OIL BEING INTRODUCED INTO THE AFTER TREATMENT SYSTEM FROM THE ENGINE
1. Remove the turbocharger outlet and inspect for signs of oil, fuel or moisture being introduced into the after treatment system from the engine.

Was engine oil, fuel or moisture found in the turbocharger exhaust outlet?

Yes

- Locate the cause of possible diesel fuel or engine oil being carried from the engine into the after treatment system. Inspect the after treatment for possible damage.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 9

9. AFTER TREATMENT DIESEL PARTICULATE FILTER
1. Remove and inspect the After treatment Diesel Particulate Filter.

Does after treatment Diesel Particulate Filter show evidence of failure?

Yes

- Replace the After treatment Diesel Particulate Filter and reset the regenerative timers with the scan tool.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.