P2000

P2000-NOX ABSORBER EFFICIENCY BELOW THRESHOLD - BANK 1





For a complete wiring diagram Refer to Diagrams/Electrical.

Theory of Operation


The engine aftertreatment system monitors the O2 content in the diesel engine exhaust. The ECM monitors the exhaust gases for oxygen content and varies the rich/lean fuel mixture of the intake air fuel mixture to adjust system. This diagnostic measures the Oxygen storage capability of the NOx Absorber Catalyst. The ECM will set the fault if it detects that the Nox Absorber performance is lower than expected. The ECM will illuminate the MIL lamp immediately when the diagnostic runs and fails. The ECM will turn off the MIL lamp diagnostic runs and passes in four consecutive drive cycles.

- When Monitored:
This diagnostic will run during deNOx events.

- Set Condition:
The ECM will set the fault if it detects that the Nox Adsorbate performance is lower than expected.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview


Diagnostic Test


1. OPEN CIRCUIT
























Disconnect the Oxygen sensor harness connector.
Disconnect the Smart O2 Sensor Module from the Aftertreatment Wiring Harness.

NOTE: Check connectors - Clean/repair as necessary.

Is the resistance less than 10 Ohms on all circuits?

Yes


- Go To 2


No


- Replace Aftertreatment Wiring Harness.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test



2. OXYGEN SENSOR




Using an ohmmeter check the resistance of the sensor heater circuit.
Is the resistance 3.2 +/- 0.8 ohms at ambient temperature?

Yes


- Replace Smart O2 Sensor Module


No


- Replace the oxygen sensor.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test
-