2014 Jeep Grand Cherokee DEF system

Norman Owner/Technician Indiana Posted   Latest  
Updated
Driveability
2014 Jeep Grand Cherokee Limited 3.0L (M EXF) 8-spd (845RE) — 1C4RJEBM3EC322493
P2BA9-00
P2BA9 — NOx Exceedence - Insufficient Reagent Quality
No Crank / No Start

Replaced the DEF tank w/pump, and the dosing valve. Attempted to clear the message in the dash many times but it is always failing due to a code that sets. The code has changed from one for pressure which we resolved with the dosing valve to P200200 for diesel particulate filter efficiency which seemed to go away with regenerating the filter after the new dosing valve was installed. Now the first code that sets is: P2BA900 for “insufficient reagant quality”. After driving further it will set P20EE00 for SCR NOx Catalyst Efficiency below threshold bank 1 and finally P200200 again.

I have read Tech Authority till blue in the face just trying to get to the information for getting it to extend the mileage for a second time from a shut down. I finally googled it and found that you have to reflash it to get another shot at extending the mileage so I have done that several times by now and attempted the healing process several times. The fluid is brand new NAPA DEF fluid, the tank and pump and dosing valve are new. The NOx numbers are higher downstream than upstream which makes no sense to me. Hoping someone out there can shed some light on this.

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Sean Diagnostician
United Kingdom
Sean
   

If the NOX reading is higher downstream than upstream Norman, then I would say you have at least one faulty NOX sensor(assuming they can't be mixed up). The fun bit is figuring out which one, if its not completely obvious. If your lucky both sensors may be the same part number and you can roll the dice, or there may be updated sensors to be fitted as a pair. I dont work on Jeep so I can't…

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Michael Owner/Technician
Florida
Michael
 

As Sean said, more than likely your issue lies with a NOx sensor. Obviously the system cannot create additional NOx between the two sensors, so it’s likely at least one sensor reading incorrectly. When we begin checking NOx sensors, we like to use a nice flat stretch of highway, set the cruise control at 70mph and watch the sensors. Do the sensors ‘wake up’ within a reasonable amount of time?…

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Kyle Mechanic
Illinois
Kyle
 

Most manufacturers provide PIDs to indicate the NOx sensor has reached its dew point and is ready to provide rational readings. Look to see if you have a NOx sensor status PID, if both sensors are reading ‘ready’ or ‘stable’ but your outlet NOx is higher then one of your NOx sensors has an implausible reading. Like Michael said, a moderate acceleration accompanied by a 0 input coast down is…

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Justin Technician
California
Justin
   

My advise to anyone in this forum with an Ecodiesel customer in the USA is to send them to the dealer if it has a check engine light . See below reasons ( GOOGLE X78 warranty extension ) - V08 recall created a warranty extension up to additional 4 years and 48 k from time recall was performed . It covers things like nox sensors , cats , DEF TANK , DEF PUMP , DEF INJECTORS , short block , etc…

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Norman Owner/Technician
Indiana
Norman
 

THANK YOU Justin!! Wow…I could have avoided days of grief and about 6 reflashes and 1 hour test drives had I asked sooner. Turns out the V08 was done this last June and it has coverage up to 200000 miles and 2026. Now to find out if we can seek customer reimbursal for what I have done or if I just back out and let them credit me the parts and make the extra labor.

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Mike Diagnostician
Ontario
Mike
   

As others have mentioned most likely a faulty NOX sensor. To test them I typically drive the vehicle as is until the sensors come online and monitor on an extended drive under steady cruise, moderate acceleration and decel to get an idea of what kind of efficiency the system is ‘seeing’. I'll then unplug the dosing valve and perform a forced regen of the DPF to clear out any stored ammonia in…

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Louis Technician
California
Louis
 

Mike, I see you mentioned a gas analyzer as a diagnostic tool for this problem. Have you used a gas analyzer in this scenario before, and if so what readings would be considered normal ? Curious, because we are a Calif. smog shop with 5 gas and dyno. We do diesel smogs as well but no tail pipe testing required. Thanks, Louis N.

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Mike Diagnostician
Ontario
Mike
 

Honestly Louis I have not. We used to have gas analyzers years back as part our of provincial emissions testing programme but that was scrapped when they moved to OBD monitors as the way forward. I have read about techs using a gas analyzer to verify the NOX readings from the sensors but cannot tell you from personal experience. Mike

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Norman Owner/Technician
Indiana
Norman Update
 

OK so for the newest on this one: Replaced both NOx sensors and now I get code P1288 00 which as near as I can tell refers to an NOx Sensor not reading correctly or perhaps the dosing injector not inputting sufficient DEF…not exactly sure where to go with this now

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Justin Technician
California
Justin
 

With the scan tool try an scr replaced routine with witech . Then post zero fueling event pre and post nox sensor values along with highway cruise nox numbers . Would also like to to know your fuel correction numbers .

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