P2000

P2000-NOX ADSORBER EFFICIENCY BELOW THRESHOLD - BANK 1





For complete wiring diagrams 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 Adsorber Catalyst. The ECM will set the fault if it detects that the Nox Adsorber 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 Adsorber performance is lower than expected.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

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. 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. Powertrain Verification Test
-