P2000-NOX ABSORBER EFFICIENCY BELOW THRESHOLD

Size: px

Start display at page:

Download "P2000-NOX ABSORBER EFFICIENCY BELOW THRESHOLD"

Betty Allen
5 years ago
Views:

1 - D - RAM 5 PICKUP - 6.7L CUMMINS TURBO DIESEL P-NOX ABSORBER EFFICIENCY BELOW THRESHOLD For a complete wiring diagram, refer to the Wiring Information. Theory of Operation The engine aftertreatment system monitors the oxygen content in the diesel engine exhaust. The Powertrain Control Module (PCM) 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 Nitrates of Oxygen (NOx) Absorber Catalyst. The PCM will set the fault if it detects that the NOx Absorber performance is lower than expected. A mobile desoot should not be performed while investigating this fault. The PCM will illuminate the MIL lamp immediately when the diagnostic runs and fails. The PCM 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 Powertrain Control Module (PCM) will set the fault if it detects that the NOx Absorber performance is lower than expected. Possible Causes MASS AIR FLOW SENSOR O SENSORS USE OF HIGH SULFUR FUEL TAMPERING OR REMOVAL OF THE NAC DEGRADED OR POISONED NAC EXHAUST, EGR OR INTAKE LEAKS Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 8 - DTC-Based Diagnostics/. OTHER DTCs. Ignition on, engine not running.. With the scan tool, read DTCs. Are any other DTCs present? Yes Repair all other DTCs first. No Go To

2 . MAF SENSOR. With the scan tool, read The Mass Air Flow sensor. Does the Mass Air Flow sensor read +/- lb/min? Yes Go To No Replace the MAF Sensor in accordance with the service information.. CHECK FOR AN OPEN CIRCUIT IN THE UPSTREAM O SENSOR. Turn the ignition off.. Disconnect the Upstream Oxygen Sensor harness connector.. Disconnect the Smart O Sensor Module from the Aftertreatment Wiring Harness. NOTE: Check connectors - Clean/repair as necessary. 4. Measure the resistance of all circuits between the O Sensor / harness connector and the Smart O Sensor Module harness connector. 6 5 SENSOR- OXYGEN / Upstream O sensor O Sensor Module MODULE-O SENSOR Is the resistance less than 5. Ohms on all circuits? Yes Go To 4 No Replace the Aftertreatment Wiring Harness in accordance with the service information. Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 8 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

3 4. CHECK FOR AN OPEN CIRCUIT IN THE DOWNSTREAM O SENSOR. Disconnect the Downstream Oxygen sensor harness connector.. Disconnect the Smart O Sensor Module from the Aftertreatment Wiring Harness. NOTE: Check connectors - Clean/repair as necessary.. Measure the resistance between all circuits in the O Sensor / harness connector and the Smart O Sensor Module harness connector. 6 5 SENSOR- OXYGEN / Downstream O sensor 5 O Sensor Module MODULE-O SENSOR 849 Is the resistance less than 5. Ohms on all circuits? Yes Go To 5 No Replace the Aftertreatment Wiring Harness in accordance with the service information. Perform the POWERTRAIN VERIFICATION TEST - 6.7L. (Refer to 8 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure). 5. OXYGEN SENSORS. Remove the Oxygen sensors and inspect for signs of soot. Is there soot on the oxygen sensors? Yes Using pressurized shop air, blow out the soot deposits by applying the pressurized air directly into the center hole of the sensors. Reinstall the sensors. Go To 6 No Reinstall the sensors. Go To 7 6. RECHECK FOR DTCS. Ignition on, engine off.. With scan tool, erase DTCs.

4 . Turn ingnition off for 75 seconds. 4. Start the engine and drive the vehicle at 5 MPH. Perform a zero fueling event (decel condition for seconds, with foot off of accelerator pedal). Repeat 5 times. 5. Ignition on, engine off. 6. With the scan tool, read DTCs. Did P or any other DTC set? Yes P by itself: Go to 7 P with any other DTC: Repair the other DTCs first. Rerun Test Step 6. Any other DTC with no P: Repair the other DTCs. Rerun Test STep 6. No Repair complete. 7. EGR SYSTEM LEAK. Look for visible signs (soot streaks) of an external EGR leak. Check the EGR Valve and EGR Cooler for signs of a leak. Are there any EGR system leaks? Yes Repair the leak. No Go To 8 8. CHECK THE INTAKE AIR SYSTEM. Perform the INTAKE AIR SYSTEM PRESSURE TEST. (Refer to 9 - Non-DTC Diagnostics/Drivability - Diesel - Diagnosis and Testing). Are there any leaks in the system? Yes Repair the leak. No Go To 9 9. CHECK FOR EXHAUST LEAKS. Perform the CHECKING THE EXHAUST SYSTEM FOR LEAKS diagnostic procedure. (Refer to 9 - Non-DTC Diagnostics/Drivability - Diesel - Diagnosis and Testing). Are there any leaks in the system? Yes Repair the Exhaust system leaks. 4

5 No Perform the AFTERTREATMENT INSPECTION GUIDELINE procedure. (Refer to 9 - Non-DTC Diagnostics/Drivability - Diesel - Diagnosis and Testing). 5

D2 - RAM 3500 PICKUP - 6.7L CUMMINS TURBO DIESEL

D2 - RAM 3500 PICKUP - 6.7L CUMMINS TURBO DIESEL 0 - D - RAM 00 PICKUP -.7L CUMMINS TURBO DIESEL PA-O SENSOR / AND / OXYGEN CONCENTRATION MISMATCH BATT A0 B(+) ELECTRONICS TOTALLY INTEGRATED POWER FUSED IGNITION SWITCH OUTPUT (RUN-START) PORT LOW PORT