P11CC
DTC P11CB or P11CC
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P11CB
- NOx Sensor 1 Performance - Signal High
DTC P11CC
- NOx Sensor 1 Performance - Signal Low
Diagnostic Fault Information
Circuit/System Description
The reductant system uses two nitrogen oxide (NOx) sensors to monitor the amount of NOx in the engine's exhaust gas. The first sensor is located at the outlet of the turbocharger and monitors the engine out NOx level. The second NOx sensor is located between the selective catalytic reduction (SCR) and the diesel particulate filter (DPF) and monitors NOx levels downstream of the SCR. The second NOx sensor also provides the engine control module (ECM) with information on the exhaust oxygen level during DPF regeneration.
Each NOx sensor contains a sensing cell, a pumping cell, and a heater. A sample of exhaust gas passes through a diffusion gap between the sensing cell and the pumping cell. The NOx sensor maintains a constant reference voltage across the sensing cell. An electronic circuit within sensor controls the pump current through the pumping cell in order to maintain a constant voltage in the sensing cell. The amount of current required to maintain the reference voltage in the sensing cell is proportional to the concentration of NOx in the exhaust.
The ECM varies the amount of diesel exhaust fluid (DEF) or reductant added by varying the reductant injector duty cycle in response to changes in engine exhaust out NOx levels.
The smart NOx sensors consist of two components, the NOx module and the NOx sensor element that are serviced as a unit. A circuit or performance condition with a NOx sensor is detected by the NOx sensor module. The smart NOx sensor module communicates the condition to the ECM over the serial data line. The ECM sets a DTC when a serial data message is received from the NOx sensor module.
Conditions for Running the DTCs
* DTCs P0101, P0171, P0172, P0234, P026C, P026D, P0299, P0401, P0402, P0480, P0483, P0526, P140B, P140C, P2228, or P2229 are not set.
* The DPF Regeneration is not active.
* The BARO is between 75-106 kPa (11-15 psi).
* The ambient air temperature is between -7 to +38°C (19-100°F).
* The engine run time is greater than 30 s.
* The engine coolant temperature is between 20 to 108°C (68-226°F).
* The engine speed is between 1200 RPM and 1800 RPM.
* The battery voltage is greater than 11 V.
* The NOx sensor is at operating temperature.
* The vehicle speed must be greater than 60 km/h (38 mph).
* The DTCs run once per drive cycle when the above conditions are met.
Conditions for Setting the DTC
The ECM receives a serial data message from the NOx Sensor Module that the NOx concentration disagrees with the calculated NOx concentration for greater than 5 s.
Action Taken When the DTC Sets
DTCs P11CB and P11CC are Type B DTCs.
Conditions for Clearing the DTC
DTCs P11CB and P11CC are Type B DTCs.
Diagnostic Aids
In order for the NOx 1 NOx Concentration and NOx 2 NOx Concentration to indicate greater than 0 ppm, the vehicle must be driven until the EGT sensor 3 is greater than 250°C (482°F).
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
Description and Operation
Exhaust Aftertreatment System Description Exhaust Aftertreatment System Description
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool. DTC UXXXX should not be set.
• If a DTC is set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
• If no DTC is set
2. Verify the following conditions do not exist :
* Intake system leaks-Refer to Charge Air Cooler Diagnosis (Full System Air Leak Test) Charge Air Cooler Diagnosis (Full System Air Leak Test)Charge Air Cooler Diagnosis (Induction System Smoke Test) Charge Air Cooler Diagnosis (Induction System Smoke Test).
* Exhaust system leaks - Refer to Exhaust Leakage Testing and Inspection
* A loose or disconnected charge air cooler hose or pipe
* Physical damage
* Soot plugged B195 NOx sensor
* Loose or missing hardware
* Loose B195 NOx sensors or B131 exhaust temperature sensors
• If a condition is found
Repair the intake or exhaust system.
• If no condition is found
3. Engine running.
4. Verify NOx 1 NOx Concentration and NOx 2 NOx Concentration are greater than 0 ppm.
Warning
Road test a vehicle under safe conditions and while obeying all traffic laws. Do not attempt any maneuvers that could jeopardize vehicle control. Failure to adhere to these precautions could lead to serious personal injury and vehicle damage.
5. Accelerate vehicle to 72 km/h (45 mph) and hold at a steady cruise until the DTC reports PASS or FAIL.
• If the DTC fails
Replace the faulty B195 NOx sensor 1.
• If the DTC passes
6. All OK.
Repair Instructions
* Nitrogen Oxide Sensor Replacement - Position 1 Nitrogen Oxide Sensor Replacement - Position 1
* Perform the scan tool NOx Sensor 1 Reset procedure after replacing the NOx sensor 1.
* Control Module References Control Module References for engine control module replacement, programming, and setup
Repair Verification
1. Install any components or connectors that have been removed or replaced during diagnosis.
2. Perform any adjustment, programming, or setup procedures that are required when a component or module is removed or replaced.
3. Clear the DTCs.
4. Ignition OFF, all vehicle systems OFF, this may take up to 2 minutes.
5. Ignition ON, perform the Reductant System Data Reset with a scan tool order to clear the DEF lamp.
• If the DEF lamp does not turn OFF, a condition with the system still exists.