P244D

P244D-EXHAUST TEMPERATURE TOO HIGH FOR PARTICULATE FILTER REGENERATION

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Exhaust Temperature Sensors are used by the Powertrain Control Module (PCM) 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 PCM provides a 5-Volt reference voltage to the sensor. The PCM monitors the voltage on the signal pin and converts this to a temperature value. When the exhaust gas temperature is cold, the sensor or thermistor resistance is high. The PCM signal voltage only pulls down a small amount through the sensor to ground. Therefore, the PCM 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 PCM senses a low signal voltage, or a high temperature. The PCM 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 fault is latched when set and can only be cleared by a scan tool.

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

- Set Condition:
The Powertrain Control Module (PCM) detects that the Exhaust Temperature is greater than a calibrated temperature for a calibrated period of time.





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

1. FUEL INJECTOR
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 before continuing.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 2

2. 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 3

No

- Go To 4

3. EXHAUST TEMPERATURE SENSORS
1. Start the engine.
2. Raise the engine speed to 2500 RPMs for two minutes.

Do the temperature readings of the Exhaust Temperature Sensors change in value at least 5°F?

Yes

- Go To 5

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.

4. EXHAUST TEMPERATURE SENSORS
1. Start the engine and allow it to idle for 10 minutes.
2. With the scan tool, read the values of the Exhaust Temperature Sensors.

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

Yes

- Go To 5

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.

5. INJECTOR RETURN FLOW TEST
1. Perform the INJECTOR RETURN FLOW TEST. 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 6

6. CHECK FOR EXCESSIVE ENGINE OIL BEING INTRODUCED INTO THE AFTERTREATMENT 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 7

7. CHECK THE AFTERTREATMENT DIESEL PARTICULATE FILTER
1. Remove and inspect the after treatment Diesel Particulate Filter.

Does the After treatment Diesel Particulate Filter show evidence of failure?

Yes

- Replace the after treatment Diesel Particulate Filter.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test