MINI R56 2009

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Re: MINI R56 2009

Postby STC » Thu Sep 07, 2017 11:05 pm

Back on topic


the lambda sensor 2 is working according to the pids, switching high and low, which is wrong if the CAT is working correctly.

Then P0420 is present or you or your Verus Guide to the Galaxy is telling lies. Period.
O2 S2 switching high and low,
with a heater Circuit Fault and still switching??? Don't think so !!


I want to learn how that is possible ??
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Re: MINI R56 2009

Postby RYM6746 » Fri Sep 08, 2017 11:52 am

Unlikely but not impossible.

Heater circuit control wire shorted to ground.
Heater circuit shorted to ground inside the ECU
Front oxy sensor signal wire shorted to rear oxy sensor signal wire with an open in the heater circuit
Corrupt scan data (we have all seen this)
Front oxy sensor, sensor plug plugged into the rear oxy sensor harness plug.
Someone left there oxy sensor simulator attached to the signal wire with an open in the heater circuit
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Re: MINI R56 2009

Postby Technician » Fri Sep 08, 2017 2:21 pm

If I am able to upload the VERUS pids I will, however I know what the 02S bank 1 sensor 2 is sending to the ECU, the ECU is then showing the response through the ECU from the sensor. I have also tested the sensor using a Fluke DMM and the lambda sensor is working. The fault codes description being presented on this thread by 'other' member is using general information only and not specific to the car in question. The MINI fault code is 2A56, this suggests the manufacturer are using their own codes and not OBD. I would like to point out that I did not read the codes from OBD either, which very well might be a good cross reference in future now I have thought about it. The code 2A56 is specific that it refers to the heater circuit, which is the only reading that showed incorrect. The customer has to date not had anything done with the car and there is still time for her to return, I also still have her car key.
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Re: MINI R56 2009

Postby STC » Fri Sep 08, 2017 10:18 pm

RYM

Unlikely but not impossible.


With the post cat O2 switching the Cat has failed and that O2 is warm enough to switch. A big "maybe" but never say never !

My knowledge and understanding is that P0420 should & will be present. In this case it is not.

Front oxy sensor signal wire shorted to rear oxy sensor signal wire with an open in the heater circuit


Indeed a famous failure on the Nissan Micra K12. One of the O2's would melt internally and shoot 12v into the signal wire of the other making it so lean that it would run on fumes and produce a fault code for the wrong sensor.

Feel free to educate me but Nissan started a policy of replacing Both O2's any time a DTC pointing at either O2 manifested itself.

"T"
If I am able to upload the VERUS pids I will


It is possible and not difficult. Verus is on a windows platform and this forum runs well on windows. I have achieved it.

Here is the evidence
topic15411-10.html
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Re: MINI R56 2009

Postby Technician » Sat Sep 09, 2017 3:54 pm

here is a screen shot

https://imgur.com/a/D5JSc
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Re: MINI R56 2009

Postby KimAndersen » Sat Sep 09, 2017 5:31 pm

Hi there

One thing that did get my attention was, when I saw the screenshot you have taken with your Versus of ecu pids.

The oxygen sensor bank 1 shows mA (milliamps) which is the value that the this oxygen sensor measure in.

This oxygen sensor on bank 1 must be a broadband sensor for my best conviction !!!.

If I recall you right - you mentioned that the front oxygen sensor bank 1 was switching like a normal oxygen sensor - is that correct !!


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Re: MINI R56 2009

Postby Technician » Sat Sep 09, 2017 6:25 pm

Hi Kim,

Thanks for replying. The front oxygen sensor to the best of my understanding is a wide band sensor and shows milli amps when switching high and low, it is indeed switching but I have no manufacturer data to compare if the tolerances are correct.

The EML was illuminated and the manufacturer codes were 2A56 and 2B68, 2A56 is the only code that returned and refers to the lambda sensor bank 1 sensor 2, which is a four wire sensor but not a wide band. According to the pid data the sensor is switching high and low, working but advising the CAT efficiency is below the manufacturer recommendations.

My concern was after following Autodata's recommended checking procedure that the PWM signal from the ECM was erratic, noisy, harsh and poor, which would not show on the scope at 5V/0.5 sec as AD recommended, hence I posted for some guidance.
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Re: MINI R56 2009

Postby KimAndersen » Sat Sep 09, 2017 9:30 pm

Hi Technician

It's clear to see from the ECU pid that this oxygen sensor isn't fully warm up at a temperature at 384 degrees celsius - the specification regarding temperature are around 780 degrees celsius for a Bosch LSU 4.9 sensor and before this sensor is fully warm - you wouldnt get any reliable output voltage from this oxygen sensor.

Do you know the manufactor of this oxygen senor ?

The only time this wideband oxygen sensor are switching above and below 450 mV are when there is no IP current control. With the correct IP current control you should have a steady voltage output at 450 mV with reference to ground.

The best way to measure a oxygen wideband sensor in regards to function and control is to measure the pump current (mA) with current clamp around IP control signal wire - it can also be measured as voltage output signal if you know the resistance of the internal RCAL resistor inside the ECU as Steve Smith has shown in this case study.

https://www.picoauto.com/library/automotive-guided-tests/bosch-lsu-4.2-broadband-oxygen-sensor/

Remember, that lambda 1 (air/fuel ratio 14.7/1) is equal to zero milliamp (mA) - your ECU pids are showing some large values in terms of milli amps.

Regards
Kim
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Re: MINI R56 2009

Postby Technician » Sat Sep 09, 2017 10:27 pm

Hi Kim,

thanks for the additional information and the link, very much appreciated. The pid data I initially provided was from the engine idling at the workshop, if I could have run the software on this forum you would see the data changes as I drive the car, but sorry that is not possible here, however I have run the pid data on the VERUS until the vertical ruler has lined up with the highest temperature achieved, which is 815 degrees C. I could be mistaken but I am to understand that the CAT temperature is recorded from lambda sensor 1 measuring the gas temperature entering the lambda before entering the CAT. If you now look at the other pids at this temperature you will see that lambda sensor 1 ma is now reading -0.00 or there about's, and the equivalence ratio is almost lambda 1.00 at 0.999.

https://imgur.com/a/0RuWf

Thank you for your advice.

Edited to add; Sorry Kim I have not got the car to hand now so I can't check the make of the lambda sensor.
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Re: MINI R56 2009

Postby STC » Sun Sep 10, 2017 10:35 pm

Still we claim a Post cat O2 switching yet no P0420 is set. Something is amiss here ?
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