Lambda unit

[Frenchtone]

Ok got an error indication, using my micro can the following is listed:-

 

-------------------------------------------------------------------------------
Address 01: Engine (J623-CFHC)       Labels:. 03L-906-018-CFF.clb
   Part No SW: 03L 906 018 QL    HW: 03L 907 309 AG
   Component: R4 2,0L EDC   H25 4785 
   Revision: 42H25---    Serial number:              
   Coding: 00190012042700080000
   Shop #: WSC 33361 790 00056
   ASAM Dataset: EV_ECM20TDI01103L906018QL 003004
   ROD: EV_ECM20TDI01103L906018QK.rod
   VCID: 042966D98F9CDB66AE-8050

1 Fault Found:
5111 - Oxygen (Lambda) Sensor B1 S1; Heating Circuit
          P0135 00 [175] - Malfunction
          MIL ON - Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Status: 00000001
                    Fault Priority: 2
                    Fault Frequency: 1
                    Mileage: 59975 km
                    Date: 2017.11.10
                    Time: 12:41:13

                    Engine speed: 0.00 /min
                    Normed load value: 0.0 %
                    Vehicle speed: 0 km/h
                    Coolant temperature: 46 °C
                    Intake air temperature: 21 °C
                    Ambient air pressure: 1020 mbar
                    Voltage terminal 30: 12.220 V
                    Unlearning counter according OBD: 40
                    Air mass: actual value (mg/stroke): 0.0 mg/stroke
                    Mean injection quantity: 0.00 mg/stroke
                    O2 sensor 1 bank 1: adjusted oxygen value: 0.00000
                    O2 sensor 1: bank 1: voltage raw value O2 signal: -3.6 mV
                    O2 sensor 1 bank 1: voltage reading Ri-signal: filtered.: 3299.8 mV
                    O2 sensor 1 bank 1: duty cycle O2 heater: 2.26 %
                    Particle filter: difference pressure: 0 hPa

Readiness: 1 1 0 0 0

 

Car continues to run 'normally' however I think the sensor needs replacing, where is it on the engine? easy replacement job? etc

 

thanks in advance

tony s

Edited 6 December, 2017 by Frenchtone

[kenfowler3966]

Presumably this is a petrol engine?

I recall a number of Fabias suffered from this a few years ago and I think it is somewhere in the exhaust system?

May well be wrong though.

[Urrell]

This is a VW bank 1 probe.
 

 

Edited 6 December, 2017 by Urrell

[Frenchtone]

no diesel

[Urrell]

This could be more like it.

 

[gianthotdog]

This is a straightforward fix.

 

i did the s1 b1 lambda sensor replacement on my superb a few months back. 

 

It is almost identical to the yeti under the bonnet (my wife has a yeti 2.0tdi 170 CFJA engine, my superb is 2.0tdi CBBB)

 

sensor was £69, sensor socket was £5-6, took me 20 minutes. Code cleared after approx 30 miles of driving. It's not been back since.

 

i did a little write up on superb forum about it with a few pics.

 

hope this helps, let me know?

[Frenchtone]

Ok, sorry for the delay, life's been a little hectic this week! However many thanks for the inputs!

More info, when the fault cleared the light  will be out for 1 or 2 trips and then relights, might be a broken/chewed wire, there are lots of mice around here, but I need to looke at the engine , and that will be Monday at the earliest, other aspects of life preclude any work on the car over the weekend.   --  later Monday I hope with some feedback!

[Frenchtone]

Ok , finally got a good day and some spare time, had a look at the piece by gianthotdog and yes the same, demounted the sensor, found a 22mm/7/8" oe  spanner worked. The sensor was black, a thichish soot layer, blew it of/out using a footpump with a reduced outlet jet, cleaned up really well, remounted the sensor and cancelled the fault code with my vcds, no error showing at the moment, but I will order one in case the same error reappears!

Thanks to Gianthotdog for pointing me in the direction to solve it.

Edited 14 January, 2018 by Frenchtone

[Frenchtone]

Ok, the 'blown' out unit failed again, light on permanently on dash display, installed a new sensor, no probs now, but a simple perhaps silly question, anyone tried warming the sensor tip with a blowtorch to just red heat? my thought being that heat level would burn off all the carbon deposit, if so did it work?

[Llanigraham]

Sounds a bit drastic,Tony.
What about leaving it to soak in some strong oven cleaner?

[Frenchtone]

thought was, the unit head looks heat burnt ie the new one, the old one covered in soot/carbon, this would create an electrical short route, and, heat treatment burns carbon, liquids could attack the sensor, most oven cleaners being alkaline I think so would need a good wash with vinegar or some weak acid to neutralise eyc, don't really know but nothing to lose its compromised now so, perhaps a weekend task!

[Edwin98]

how did you sorted it out ?

[Frenchtone]

I eventually had a chat here a la frog with an independant , ancient, VW specialist, he  said it was the sensor and just to replace it, found one on ebay for about £30.

replaced it and as they say that solved the problem, took about 10 mins in total!

General view is that they should be good for about 80k-100k, mine failed at about 35-36k, No subsequent probs.

[aubrey]

There are often 2 lamda sensors. I note your error is B1 S1. S1 is on the engine side of the catalyst, so often on the end of the exhaust manifold. S2 is on the exhaust out side of the catalyst.

B1 is bank 1, so unless you get multiple cylinder heads like a V or W engine, it will always be Bank 1.

I had to change the S2 one on my Yeti 1.2 Petrol, which was quite easy to access from underneath. The S1 on mine would of been really easy from just having the bonnet open.

Note when ordering S1 and S2 are different part numbers with different cable lengths and connectors.

[blouis79]

Bosch diagnostic info on lambda sensors is worth a read. Specifically says not to clean the outside with high pressure water cleaner. Presume same applies to inside...

 

https://www.google.com.au/url?sa=i&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=0CAMQw7AJahcKEwjY3927mZH7AhUAAAAAHQAAAAAQAg&url=https%3A%2F%2Fwww.boschaftermarket.com%2Fxrm%2Fmedia%2Fimages%2Fcountry_specific%2Fsg%2Fservices_and_support_6%2Fdownloads_18%2Flambda_sensors.pdf&psig=AOvVaw3olYHsTaUNKm5Ke74txnZX&ust=1667536972646052

 

NOTE: Service manual says to coat new sensor threads with VW antiseize. But Bosch says oxygen sensors are pre-coated with antiseize compound. (Bosch sensor on order.)

Edited 3 November, 2022 by blouis79
added

[blouis79]

Sorry about bad link. Hope this one is better. This is the most helpful of all the Bosch documents I have read - start at page A10.

http://aa-bosch-ecat-ap.resource.bosch.com/sao_ecat/downloads/Bosch%20Australia%20Oxygen%20Sensor%20Catalogue%202013.pdf

 

Specifically:

Calibration resistor is built into the plug - don't mess with it.

Sensor voltage test voltmeter or oscilloscope with engine running is the most likely to be helpful - access to connectors is extremely difficult though.

Service life of planar sensors is quoted at 160,000km. Can't yet find specific number for diesel, suspect it to be lower.

Reduced output from sensor implies oxygen level closer to atmospheric (i.e.lean), resulting in compensation to rich mixture and worse fuel consumption.

 

In my Yeti, the obvious symptoms were more frequent DPF regen and increased fuel consumption.

 

So have replaced the oxygen sensor with the Bosch aftermarket one.

 

Tips:

1. On my Yeti, the exhaust manifold to turbo clamp was positioned with allen bolt head to rear close to the sensor. Really should be repositioned with clamp at the front the bolt head pointing up. As it was, it obstructed access to the oxygen sensor by all tools and needed to be loosened and pried free at top front.

2. 22mm flare nut wrench would probably work fine. I bought a cheap oxygen sensor open sided 6 point short socket with outrigger and a long open sided 12 point oxygen sensor socket. Both worked ok.

3. Study the firewall cable mounting clips to figure how to release without breaking, since the Bosch supplied replacements are *not* the same. Difficult to both see and access. One had a clip arrangement similar to the Bosch replacement but length of standoff is short. Other has a ratchet to release with small screwdriver.

4. Oxygen sensor plug has to be pried forward in its clip - access the gap from below.

5. Oxygen sensor socket has a pry hole in the side to release the catch.

 

Fuel consumption now is reporting better than *ever* on maxidot.

[blouis79]

As far as I can find, there is only one lambda sensor on a TDI engine. Early CR TDI self study program shows lambda sensor in the DPF housing after the turbo. CFHC 103kW TDI in my Yeti is apparently "generation 2 CR TDI" for which I can find no self study program describing specific improvements. Lambda sensor between intake manifold and turbo probably has better thermal stability and longer life. Bosch says most likely reason for lambda sensor failure is poisoning by chemicals in fuel additives. Premium fuels have according to the fuel companies more additives, which in turn may reduce the life of the lambda sensor.

[Urrell]

3 hours ago, blouis79 said:

Lambda sensor between intake manifold and turbo probably has better thermal stability and longer life.

How is that going to measure the oxygen in the exhaust gasses there?

[J.R.]

Because it would be in the exhaust manifold which Blouis probably meant to write but nonetheless what he wrote is still actually correct!

[blouis79]

(obviously the brain was a bit foggy and clearly the lambda sensor is on the exhaust side.)

 

So after a few more tanks of diesel and injector cleaner, real fuel consumption is still high. Cooling fan is still running on presumed turbo timer on switch off. New MAF sensor seems to have fixed it and Yeti appears to behave like normal. Bosch 0281002956 is a one piece unit made in Germany.

 

Maxidot seems to continue to lie at the moment, with reported fuel consumption way lower than real. Still can't find what data feeds the fuel consumption figure. If the computer used fuel input and km travelled, then the number should be close to real.

 

I read that hot-film MAF sensors tend to cause rich running at idle and lean at high RPM.

 

I couldn't find any clues in VCDS that the MAF sensor was misbehaving.  Can't find an injector offset out of range.

 

I did try unplugging to see if connector corrosion might be a cause. Later got a random fault in the middle of gearchange off throttle with clutch disengaged, the engine ran up to redline then back to normal. VCDS reported no faults after the fact. Not sure what could cause that. Any ideas????

 

Curiously there is contamination of scant oily residue in the intake ducting which presumably comes from the vacuum hose upstream of the MAF sensor. Air box after air filter is spotless. This presumably is the source of sensor contamination. Looks like the first option for next time fuel consumption runs high is to change the MAF sensor - an extremely easy job once the sensor plug lock mechanism is understood (pull up lock tab and then squeeze to unlock and pull plug).

[Urrell]

13 hours ago, blouis79 said:

Cooling fan is still running on presumed turbo timer on switch off.

No, that'd be an interrupted DPF regeneration.
That's why the fuel consumption is high.
Use an OBDII adapter with an Android VAG DPF Lite app (FREE) to see the state of the DPF to confirm that.