P200E

P200E-CATALYST SYSTEM OVER TEMPERATURE - BANK 1





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

Theory of Operation

The Aftertreatment Diesel Oxidation Catalyst is designed to react with hydrocarbons in the exhaust stream, this reaction produces heat. The heat can become excessive if too much hydrocarbon enters the Aftertreatment Diesel Oxidation Catalyst too quickly. Excessive heat can damage the diesel aftertreatment components, so the temperature of the aftertreatment system is closely monitored by the electronic control module (ECM). The Exhaust Temperature sensors are used by the ECM to monitor the engine exhaust temperatures in the aftertreatment 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 pin 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 illuminates the CHECK ENGINE light immediately when the diagnostic runs and fails. Active regeneration of the aftertreatment particulate filter will be disabled. The DTC can only be cleared by a scan tool.

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

- Set Condition:
The Engine Control Module (ECM) detects that the aftertreatment diesel oxidation catalyst 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 Fuel Injector DTCs.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 2

2. 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 aftertreatment system for possible damage.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. EXHAUST TEMPERATURE SENSOR(S)
1. Turn the ignition off for five minutes.
2. Turn the ignition on.
3. With the scan tool check the temperature values of the Exhaust Temperature sensors.

Are the Exhaust temperature sensors reading within 25°C (77°F) of each other?

Yes

- Go To 4

No

- Replace the Exhaust Temperature Sensor that is out of range as compared to the others.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. 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 aftertreatment 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 aftertreatment system. Inspect the aftertreatment system for possible damage.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 5

5. AFTERTREATMENT SYSTEM
1. Remove and inspect the Aftertreatment system.

Does aftertreatment diesel oxidation catalyst show evidence of failure?

Yes

- Replace the Aftertreatment diesel oxidation catalyst.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

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