# Cel p11dc



## warloc (Dec 10, 2013)

Is there anyway that your code was a P11D7 instead of P11DC? I ask you because I have got this code a couple of times in the last 35K miles. I bought a code reader soon after a couple CEL's right after I bought the CTD to avoid the dealer visits.


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## Danny5 (Dec 22, 2011)

You should post about it here:

http://www.cruzetalk.com/forum/201-...-diesel-trouble-codes-containment-thread.html


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## Scott M. (Apr 23, 2013)

warloc said:


> Is there anyway that your code was a P11D7 instead of P11DC? I ask you because I have got this code a couple of times in the last 35K miles. I bought a code reader soon after a couple CEL's right after I bought the CTD to avoid the dealer visits.


P11D7 is a NOX sensor calibration signal problem. I cant help with a P11DC. Sorry.


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## Barefeet (Jan 1, 2014)

Scott M. said:


> P11D7 is a NOX sensor calibration signal problem. I cant help with a P11DC. Sorry.


The paperwork from the dealer said. "Check engine light is on - Cau diagn dtc P11DC, ,test per PIP5135 Found leaking air cleaner outlet duct." Replace duct assembly.
It seems to be fixed now.


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## Scott M. (Apr 23, 2013)

Great. Thanks for the follow up. Did you notice any fuel type smells in the car especially at idle ?


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## Barefeet (Jan 1, 2014)

Scott M. said:


> Great. Thanks for the follow up. Did you notice any fuel type smells in the car especially at idle ?


Nothing abnormal, however, I thought the mileage was a little lower than normal.


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## LulzT1 (Aug 24, 2015)

Gonna bump this thread ... Got CEL yesterday morning, same P11DC, phone doesn't have details for it. No real fuel smell, but have have noticed a solid 5mpg loss based on what would be "normal" for me. (Usually 49-50mpg per 25miles straight highway, now lucky to hit 45mpg..)

Car goes in tomorrow. Again. 6th time in only 18k miles !


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## Barefeet (Jan 1, 2014)

LulzT1 said:


> Gonna bump this thread ... Got CEL yesterday morning, same P11DC, phone doesn't have details for it. No real fuel smell, but have have noticed a solid 5mpg loss based on what would be "normal" for me. (Usually 49-50mpg per 25miles straight highway, now lucky to hit 45mpg..)
> 
> Car goes in tomorrow. Again. 6th time in only 18k miles !


Sorry to hear. I'm at 32k 1-O2 sensor, 1-NOX and the air duct. Good luck.


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## LulzT1 (Aug 24, 2015)

Ok so dealer just called and told me a/the knock sensor failed. Not sure if/how that's related to P11DC ?

Would make sense though with loss in mileage as I'm sure motor is in limp mode.. Will try to log it to verify for my own sake.

Told me to pick the car up while they wait for the part, claims its ok to drive for now based on GM tech. I'm not risking fouling out the exhaust system again, so probably DD the racecar for now ..


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## Tomko (Jun 1, 2013)

Given that Diesel engines do not have an ignition system, I had no idea that they had a knock sensor.


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## oilburner (Jun 13, 2013)

Tomko said:


> Given that Diesel engines do not have an ignition system, I had no idea that they had a knock sensor.


Tomko this motor does not have a knock sensor. checked all 8 pages of wiring diagrams for eng management at work yesterday an it is not there. the normal noise from this eng would drive a knock sensor crazy.


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## Tomko (Jun 1, 2013)

LulzT1 said:


> Ok so dealer just called and told me a/the knock sensor failed. Not sure if/how that's related to P11DC ?





Tomko said:


> Given that Diesel engines do not have an ignition system, I had no idea that they had a knock sensor.





oilburner said:


> Tomko this motor does not have a knock sensor. checked all 8 pages of wiring diagrams for eng management at work yesterday an it is not there. the normal noise from this eng would drive a knock sensor crazy.


Thanks oilburner. 

LulzT1 - I suggest that you tell your dealer that your bull$h!t sensor is working and that there is no knock sensor on this engine.


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## Cruzator (Dec 31, 2014)

Shopkeypro says P11DC is NOx Sensor 2 Current Performance


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## Cruzator (Dec 31, 2014)

[h=3]2014 Chevrolet Cruze 2.0L Eng Diesel[/h][h=3]Circuit/System Description[/h] 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 after the selective catalytic reduction (SCR) and monitors NOx levels downstream of the SCR.
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.




P11DC 


DTCs P064C, P163C, P220A, P220B, P22A3, P229E, U029D and U029E are not set.
The EGT sensor 3 is between 100-600°C (212-1112° F).
The engine speed is greater than 600 RPM for 5 minutes.
The battery voltage is greater than 11 V.
NOx sensor 1 and NOx sensor 2 status shows activity.
The fault exists for more than 3 events during a key cycle.
The DTC runs continuously when the above conditions are met.


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## revjpeterson (Oct 2, 2013)

Cruzator said:


> *2014 Chevrolet Cruze 2.0L Eng Diesel*
> 
> *Circuit/System Description*
> 
> ...


Any chance you could post this information for P11D7 as well? I've been trying to locate the cause of that code on my vehicle, but all I can get is that it generally has something to do with a NOX sensor, but no data as specific as this. 

Thanks!


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## Cruzator (Dec 31, 2014)

LulzT1 said:


> Ok so dealer just called and told me a/the knock sensor failed. Not sure if/how that's related to P11DC ?
> 
> Would make sense though with loss in mileage as I'm sure motor is in limp mode.. Will try to log it to verify for my own sake.
> 
> Told me to pick the car up while they wait for the part, claims its ok to drive for now based on GM tech. I'm not risking fouling out the exhaust system again, so probably DD the racecar for now ..


Are you sure they said KNOCK SENSOR and not NOx sensor? Sounds the same. Could be a misunderstanding. Just wondering.


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## Cruzator (Dec 31, 2014)

Here ya go, Rev!


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[h=3]2014 Chevrolet Cruze 2.0L Eng Diesel[/h] 




[h=2]DTC P11D7 or P22FE[/h] [h=3]Diagnostic Instructions[/h] 

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic approach.
 Diagnostic Procedure Instructions provides an overview of each diagnostic category.
 
[h=3]DTC Descriptors[/h] DTC P11D7 NOx Sensor 2 Performance - Sensing Element Status Signal
DTC P22FE NOx Sensor 2 Performance - Sensing Element

[h=3]Diagnostic Fault Information[/h] 
CircuitShort to GroundOpen/High ResistanceShort to VoltageSignal PerformanceNOx Sensor Ignition VoltageU029D, U029E, P220A, P220BU029D, U029EU029D, U029E, P220A, P220B-High Speed GMLAN Serial Data (+)U0074, P205DU010E, P205DU0074, P205D-High Speed GMLAN Serial Data (-)U029D, U029E, U010E, P205DU010E, P205DU010E, P205D-NOx Sensor Ground-U029D, U029E--
 
[h=3]Circuit/System Description[/h] 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 after the selective catalytic reduction (SCR) and monitors NOx levels downstream of the SCR.
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.

[h=3]Conditions for Running the DTCs[/h] 

DTCs P0101, P0234, P0299, P0401, P0402, P140B, P140C, P2200, P2202, P2203, P2205, U029D and U029E are not set.
Battery voltage is greater than 11 V.
Ambient air temperature is greater than -7°C (19°F)
Engine speed is less than 1000 RPM for at least 10 s.
BARO pressure is greater than 75 kPa (11 psi).
EGT sensor 3 is between 50-500°C (112-932° F).
NOx 2 NOx Concentration is less than 200 ppm.
The DTC runs during key off after-run after the above conditions are met and the fault exists for more than 3 events during a key cycle.
 
[h=3]Conditions for Setting the DTC[/h] Due to aging and poisoning of the sensor element, the characteristics could change and have to be monitored. Therefore, a self diagnosis is implemented within the sensor control unit which is determining a measurement deviation in relation to a reference point defined during sensor production.
P11D7 
The NOx sensor control unit sends a unique message to the ECM upon the self-diagnosis being aborted. The number of aborts is tracked by the ECM. If the number of self diagnostic aborts exceeds a threshold, the DTC is set.
P22FE 
The NOx sensor self diagnostic result is received from the NOx sensor control unit and stored in a ring buffer, which takes the average of the last calibrated number of test results and averages them for comparison to an upper and lower calibrated threshold. If the average result is greater than or less than the calibrated thresholds, a NOx sensor self diagnostic fault will set.

[h=3]Action Taken When the DTC Sets[/h] DTC P11D7 and P22FE are Type B DTCs.

[h=3]Conditions for Clearing the DTC[/h] DTC P11D7 and P22FE are Type B DTCs.

[h=3]Diagnostic Aids[/h] 

DTC P11D7 may falsely set while the vehicle is in for service if the vehicle is connected to the repair facilities exhaust ventilation system. This is more prevalent in shops where ventilation systems have strong suction.
If the vehicle has been started and ran for less than 60 s, then shut down, DTC P11D7 may set.
 
[h=3]Reference Information[/h] Schematic Reference
Engine Controls Schematics 
Connector End View Reference
COMPONENT CONNECTOR END VIEWS - INDEX 
Component View Reference
Powertrain Component Views 
Description and Operation


 Exhaust Aftertreatment System Description
 Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Level) , Diesel Exhaust Fluid (DEF) Warning Strategy (DEF Quality) , Diesel Exhaust Fluid (DEF) Warning Strategy (Anti-Tampering) , Diesel Exhaust Fluid (DEF) Warning Strategy (Emission Control)
 Electrical Information Reference


 Circuit Testing
 Connector Repairs
 Testing for Intermittent Conditions and Poor Connections
 Wiring Repairs
 DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions 
Scan Tool Reference
Control Module References for scan tool information.

[h=3]Circuit/System Verification[/h] 

Ignition On.
Verify DTC UXXXX is not set.
If a DTC is set Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

If no DTC is set 

Verify the following conditions do not exist:
Induction system leaks - Refer to Induction System Smoke Test in Charge Air Cooler Diagnosis (Induction System Smoke Test) , Charge Air Cooler Diagnosis (Induction System Air Leak Test) .
Exhaust system leaks - Refer to Exhaust Leakage
Physical damage.
Soot plugged B195 NOx Sensor.
Loose or missing hardware.
Loose B195 NOx.

If a condition is found Repair the intake or exhaust system.

If no condition is found Replace the B195 NOx Sensor - Position 2.

 
[h=3]Repair Instructions[/h] 

 Nitrogen Oxide Sensor Replacement - Position 2
Perform the scan tool NOx Sensor 2 Reset procedure after replacing the NOx sensor 2.
 Control Module References for engine control module replacement, programming and setup.
 
[h=3]Repair Verification[/h] 

Install any components or connectors that have been removed or replaced during diagnosis.
Perform any adjustment, programming or setup procedures that are required when a component or module is removed or replaced.
Clear the DTCs.
Ignition Off, all vehicle systems Off, this may take up to 2 minutes.
Ignition On, perform the Reductant System Quality Test with a scan tool.
Engine idling for at least 5 min.
Ignition Off, all vehicle systems Off for 5 min.
Ignition On, verify the DTC is not set.
If the DTC is set A condition with the system still exists.

If the DTC is not set 

All OK.


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## Robby (Mar 1, 2013)

LulzT1 said:


> Ok so dealer just called and told me a/the knock sensor failed. Not sure if/how that's related to P11DC ?
> 
> Would make sense though with loss in mileage as I'm sure motor is in limp mode.. Will try to log it to verify for my own sake.
> 
> Told me to pick the car up while they wait for the part, claims its ok to drive for now based on GM tech. I'm not risking fouling out the exhaust system again, so probably DD the racecar for now ..


I'm going to, after reading the thread, redefine (if needed) that the dealer probably called you to say the NOx sensor failed….that was likely interpeted as the 'Knock Sensor' failed……and reported as such.

As a tired old wrench, we call the component (phonetically) a 'Knocks' sensor……as opposed to a Nitrogen Oxide (NOx) content sensor.
I guess this can easily be confused with a 'Knock Sensor' which is a vibration reading component found in gasoline engines.

Kinda funny to read though.
Rob


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## LulzT1 (Aug 24, 2015)

Cruzator said:


> Are you sure they said KNOCK SENSOR and not NOx sensor? Sounds the same. Could be a misunderstanding. Just wondering.


Funny thing is when he called I said KNOCK or NOx ? And he said no, knock is in knock on the table ... So I said well wtf do I know, I'm new to the whole clean diesel world anyway.

It's possible he misunderstood the tech. As long as the guy with the wrench knows what he's doing then we're good lol otherwise I'm SOL!


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## Barefeet (Jan 1, 2014)

My dealer did the same. The mechanic installed a nox sensor, the office help typed knock sensor in their computer. The service manager told me they replaced the "knock sensor". I questioned him that I thought it would be nox he said he didn't know.


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## Zenturi (Jan 25, 2014)

LulzT1 said:


> Car goes in tomorrow. Again. 6th time in only 18k miles !


Well now I don't feel quite so annoyed ... got my 3rd CEL tonight, at 18,800 miles.

I'm already thinking I'd better get the extended warranty on this car when my 3 years is up from GM.


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## LulzT1 (Aug 24, 2015)

Barefeet said:


> My dealer did the same. The mechanic installed a nox sensor, the office help typed knock sensor in their computer. The service manager told me they replaced the "knock sensor". I questioned him that I thought it would be nox he said he didn't know.


As you and many others stated, service rep misunderstood. It was in fact a failed NOx sensor. Had it replaced under warranty. Maybe I'll make it more than 1k miles before the next CEL lol although I test drove a '14 sonic for the time being... Man did I miss my Cruze!



Zenturi said:


> Well now I don't feel quite so annoyed ... got my 3rd CEL tonight, at 18,800 miles.
> 
> I'm already thinking I'd better get the extended warranty on this car when my 3 years is up from GM.


I actually did get an extended warranty when I bought the car b/c I had a feeling being a first gen Cruze diesel in the U.S. I would run into problems. Didn't think I'd be a regular at the shop lol


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## revjpeterson (Oct 2, 2013)

Cruzator said:


> Here ya go, Rev!


Thanks - now to get on to the diagnosing. 

Since this says it refers to NOX2, I know where to look, and I suspect it might have something to do with the repair I made to the Particulate Matter Sensor a couple months back. The two are right next to each other and their wires run back to the harness together. I didn't re-secure the wires after replacing the Particulate Matter Sensor, (the routing seemed safe without it) so perhaps something got pinched or the road vibration wore through the insulation and caused a short to ground.


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## DieselDallas (Sep 4, 2017)

Is the car safe to drive with this cel (p11dc) code?


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