Exhaust System Engine MIL on; fault code P2A01

Discussion in '4th Generation (2013-2017)' started by Lisbon, Friday 25th Mar, 2016.

  1. Lisbon Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Reading
    Engine MIL came on and stayed on whilst cruising on dual carriageway. Honda Assist diagnostic check showed above fault code, described as 2nd oxygen sensor on DPF. Fault cleared by AA, but has come back on after further 20miles. No other symptoms and car drives/runs fine. Dealer can't look at it until end of next week. I've looked through forum and guides, but cannot find much on this. Is this a common or known fault on the new CR-V diesels, if so does replacement sensor usually solve the issue, or is it prone to keep throwing up fault code without a fault being found. Is it okay to drive so long as cars runs normally? Thanks
  2. SpeedyGee Administrator Staff Team

    England Speedy Birmingham
    Looking at the code I'd say it's an issue with the rear O2 sensor or the wiring sensor to it or the connections.
  3. Lisbon Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Reading
    My understanding is the secondary sensor is mainly to monitor condition of the DPF. If so, and the car is in all respects running fine, am I right in thinking the car is okay to drive in the meantime? Any help/advice appreciated.
  4. Ichiban Founder Staff Team

    England CJ Leeds
    That's the flow chart to diagnose this issue, most probably you will need to speak to the dealer to upgrade the ECM software

    upload_2016-3-29_21-45-24. upload_2016-3-29_21-47-27.
    When shifting to deceleration driving (fuel cut-off) from normal driving condition, the output of air/fuel ratio (A/F) sensor 2 is shifting to ambient condition. When the deviation is equal to or more than specified value based on the atmospheric O2 concentration at that time, it temporarily detects a malfunction. When the state of temporary detection continues to be equal to or less than specified value for few seconds, the powertrain control module (PCM) detects a malfunction and stores a DTC.

    Malfunction Threshold
    If consecutively continued for 5 seconds or more after the condition shown below from a deceleration fuel cut-off state:
    When the output of A/F sensor 2 (O2 concentration) after fuel cut-off is equal to or more than specified value with atmospheric O2 concentration as a standard.
    When the output of A/F sensor 2 (O2 concentration) after fuel cut-off is equal to or less than specified value with atmospheric O2 concentration as a standard.
    Possible Cause
    NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
    A/F sensor 2 range/performance problem
    Confirmation Procedure
    Operating Condition
    1.Start the engine, and hold the engine speed [ENGINE SPEED] at 2,000 min-1 (rpm) without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.
    2.Test-drive under these conditions:
    Engine coolant temperature [ECT 1] above 70 °C (158 °F)
    Drive the vehicle with engine speed at 1,500 min-1 (rpm) or more, then decelerate (with throttle fully closed) from 1,500 to 1,250 min-1 (rpm) for 5 seconds or more
    Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
    With the HDS

    Diagnosis Details
    Conditions for setting the DTC
    When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

    Conditions for clearing the DTC
    The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command.
  5. Lisbon Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Reading
    @Ichiban thank you for the technical info.
  6. busmeister Junior Member ☆ ☆ ☆ ☆ ☆

    i have same issue at the moment..............and i`m nerved about this.
    but one question. what is LAF2 IA line ??
  7. Lisbon Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Reading
    @busmeister My take on the flow chart is it is to attempt to diagnose whether the fault is due to:
    1. a sensor failure (A/F sensor 2) or
    2. a fault in the wiring circuit (LAF2 IA) or
    3. a software related issue in the PCM (LAF2 IA)

    Dealer has now replaced A/F sensor 2 in my vehicle and has cleared DTC. All ok so far, but time will tell if this resolves the issue. As previously stated, my understanding is the A/F sensor 2 has a primary monitoring function and if the vehicle is otherwise running A1, then it's unlikely there is major underlying failure. Please post how you get on, this is a relatively new engine configuration and it is useful to hear of faults and how they are resolved.
  8. busmeister Junior Member ☆ ☆ ☆ ☆ ☆

    ok, my dealer already replaced Sensor 2. I drove about 1000km and then, directly after DPF reg.!!!!!, the MIL lit again. Now they talk with Honda. Honda says the dealer should replace 2nd Sensor again , do oilchange(??)
    and then we will see. This is my Status at the moment.
  9. Lisbon Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Reading
    Sorry to hear your problems continue.

    This is ensure engine oil is not contaminated with diesel from DPF regen. How many km has your vehicle done? Have you noticed oil level rising on dipstick when checking oil? Check dealer is using recommended oil spec, not all in the UK do so. See link to chart below:

    Honda oil application chart 16YM (Bulletins & Advisories - )

    If you don't already, consider using premium diesel.

    These diesel engine emissions systems are so complex now that small changes can have significant impact.

    Add you vehicle to the garage section and include vehicle details in your profile. That way everyone can see your vehicle details making it easier for people to respond.
    FirstHonda likes this.
  10. busmeister Junior Member ☆ ☆ ☆ ☆ ☆

    My Car has now running 3800km and i don`t see a rising oil level. I think, if it is an authorized Dealer , he should know the correct Oil, but i will indicate him.
  11. busmeister Junior Member ☆ ☆ ☆ ☆ ☆

    ok, update.

    My Car was in Garage. New A/F Sensor 2 and Oil Change from 5W30 to 0W30. Now we will see how long i will be without MIL. Honda said they have no more ideas !!!!!
  12. 155695 Premium Member Club Supporter

    England Keith Essex
    Interesting this oil issue. It appears there are at least 2 types that may be used in the CR-V. I say that (as I mentioned in a thread I created the other day regarding servicing) on the basis that my car is just coming up to a year old and the main dealer I bought it from e-mailed me reminding me that its 1st service is due.

    One of the "extras" offered was the opportunity to "upgrade" the oil, plus few other bits and pieces for the "fantastic" additional cost of £39.99. As I mentioned in the original post and will undoubtedly raise with the dealer when I take it in, why are they putting an inferior (by inference) oil in during the service in the 1st place.

  13. busmeister Junior Member ☆ ☆ ☆ ☆ ☆

    ok, i don't pay for that oil. Honda Technical Research says > change and dealer do so. It´s coverd by Warranty.
    - - - Updated - - -
    Interesting. Drivers Manual says on Page 547 "use Oil 0W30 for European and Ukraine Diesel Engines". Filled was the "wrong??" 5W-30 from Factory and now the "correct" Oil 0W30 is in. Don`t know if this make a different for Sensor Measuring.
    Maybe lower or higher O2 Content ?? Mysterious, mysterious.
    - - - Updated - - -
    i will resolve this Puzzle........................some day....................maybe at End of my Life :-D

    ah........and greets from a German BVB Fan to alle Liverpool Fans ;-D. Good Job, Kloppo ;-D
    FirstHonda likes this.
  14. Lisbon Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Reading
    It's puzzling as to what effect changing the oil will have at such low km. The factory fill oil should already be 0W-30 and in any case as long as its low sulphur C2/3 spec both are compatible for use in vehicles fitted with DPF. One faulty AF2 sensor is unfortunate, for the replacement to be faulty as well is too much of a coincidence. After all, these are not cheap parts and their failure rates should reflect this.

    As an aside, the Honda engine oil I have for topping up does not specify either the viscosity or ACEA spec on the bottle, it just refers to engine oil for use in Diesel Earth Dream engines.
  15. MikeM-271048 Senior Member ★ ★ ☆ ☆ ☆

    Italy Mike Bruno
    Does it freeze in Marburg during the winter? As I understand it (and I am very open to correction) the only difference between 0W-30 and 5W-30 would be the minimum temperature at which it is expected to operate. There has to be some margin as the temps here in NW Italy are regularly under -10 in a normal winter. And AFAIK we are in Europe (at least until 23 June).
  16. busmeister Junior Member ☆ ☆ ☆ ☆ ☆

    no, we had a very mild winter, but i have the feeling that the engine comes faster to it`s operating temp. , maybe it`s wrong, because the ambient temp is now higher , too.
    don't know. very mysterious for me.
    - - - Updated - - -
    will see what time brings
  17. RTI Junior Member ☆ ☆ ☆ ☆ ☆

    Moldova, Republic Of RTI Chisinau
    Exactly, 0w30 will guarantee you a cold start @ -35 degrees celcius and 5w30, respectively @ -30. The "30" digits after w show the viscosity of the oil when the engine is at its operating temperatures.
  18. busmeister Junior Member ☆ ☆ ☆ ☆ ☆

    Hello Guys,

    are there any News about that Problem ? I specially ask Ichiban. Maybe Honda (Dealers) gained new insights.
    My Car is now running 2000km without problem. But my feeling is, that the Problem comes again.

  19. Lisbon Senior Member ★ ★ ☆ ☆ ☆

    United Kingdom Reading
    3,000km since sensor was replaced and all is well.
    Ichiban and busmeister like this.