The S H E car

bretti_kivi said:
got one of those in my car, too... need to remove it before inspection. Thanks for the reminder on the mats, too - daughter asked about those yesterday. Where did you get them from? Ebay?

- Bret
Click to expand...
Check out ahw-shop.de, I think the mats are only like 27euro plus shipping.
 
Joga said:
SHE now reports some unconvenience to my partner, the cartaker rather than the caretaker of SHE.
View attachment 71553
Runs well but light on nevertheless.
Click to expand...

A VCDS readout gave this:

Address 01: Engine Labels: 036-906-034-APE.lbl
Part No: 036 906 034 Q
Component: MARELLI 4LV 3720
Coding: 00051
Shop #: WSC 40970
VCID: 2045C7D5A028698633-4B1A
WAUZZZ8ZZ1N035707 AUZ7Z0Y1745581

1 Fault Found:
17604 - Oxygen (Lambda) Sensor Heater Circuit: B1 S1
P1196 - 35-00 - Electrical Malfunction
Readiness: 0000 0000


I am not sure if this is about the first Lambda sensor, at the exhaust manifold? Or the second one?
 
I havent been able to find out with 100% confidence, but from googling it seems that this info:
" 17604 - Oxygen (Lambda) Sensor Heater Circuit: B1 S1 "
points to the first lambda sensor, near the exhaust manifold.
If the "S1" had been a "S2" that would point to the second lambda sensor near the second cat.
But these are just my interpretations and assumptions so far.
If anyone can confirm it that would be great.
 
In the meanwhile I am working on the hypothesis that it is the first lambda sensor which is bad (or its wiring!).

From part supplier sites this should be a NTK 1825 sensor, a wideband lambda sensor and quite pricey, and with five connecting pins.

My plan now is to locate the lambda sensor, disconnect it from the vehicle harness and ohm-measure the sensor heating circuit to conclude on whether the sensor or the harness is at fault.

Does anyone know which two pins out of the five pins are for the heater?
I dont have any circuit diagrams to consult.
 
Joga said:
In the meanwhile I am working on the hypothesis that it is the first lambda sensor which is bad (or its wiring!).

From part supplier sites this should be a NTK 1825 sensor, a wideband lambda sensor and quite pricey, and with five connecting pins.

My plan now is to locate the lambda sensor, disconnect it from the vehicle harness and ohm-measure the sensor heating circuit to conclude on whether the sensor or the harness is at fault.

Does anyone know which two pins out of the five pins are for the heater?
I dont have any circuit diagrams to consult.
Click to expand...
PM Sent. - Andy
 
I have now located the (first = upstream) lambda sensor.
It is under the heat shield:

DSC_7720_LI.jpg


Sensor itself, and its connector:
DSC_7722_LI.jpg





I unplugged the connector:
DSC_7743.JPG



And noted that two of the wires on the vehicle side of the connector were considerably thicker than the other ones.
I assumed that those were for the heater.
DSC_7747.JPG




I then made Ohm-measurement on the sensor side of the connector at the heater pins:
DSC_7752.JPG


So around 3 Ohm resistance (measured at cold sensor/engine).
I dont know exactly what is a normal value, but NTK says if above 30Ohm would be abnormal.
So this COULD be a normal value.
At least I know now it is not open-circuited, i.e. not obviously bad.


I restored the connector and connected VCDS.


Engine ECU is not happy, still same error code, and the heater resistance for (lambda sensor) bank 1 is not present at all:
DSC_7774 (2).JPG


Conclusion so far:
Sensor is not obviously bad (3 Ohm). ECU not happy.
Next step: find out wich pins at engine ECU that correspond to the pins at the sensor connector, and then Ohm-measure the harness to see its condition.
 
Joga said:
Next step: find out wich pins at engine ECU that correspond to the pins at the sensor connector, and then Ohm-measure the harness to see its condition.
Click to expand...
The lambda sensor heater is fed with 12V via the fuel relay and fuse SB19. It is then pulled down by engine ECU at its pin5. I checked both of those lines for resistance (was 0,3Ohm), and isolation to chassi (was more than 100kOhm) so the conclusion is that harness is ok.
_20201025_221701.JPG

Also checked that high side can supply enough current and that low side can sink enough current by replacing the sensor heater with a 21W lamp.
It was shining bright.
Ok, I will now order a new sensor :) for 107euro.
 
Cool reading!

Believe the 1.4i lambdas fail «all the time» and heard they can be a pig to get out. So be careful so you do not destroy the whole cat.
 
The new sensor arrived the other day and I started to remove the old one.
I think the right way is to remove the exhaust manifold heat shield to get good access to the lambda sensor.
But those M6 screws looked rather stuborn.
Instead, after some fiddeling I actually managed to remove the sensor with this tool setup.
_20201030_211413.JPG

So this tool is every thing needed to remove the upstream lambda sensor on a 1.4 petrol ?.
 
Old and new sensor, a, NTK 1825.
Looks very much the same (which is what I expected).
_20201030_212427.JPG
 
Last edited:
Jag tror inte på det ;)

But enough Google translate! You guys had frost yet? I was washing cars earlier and the first rinse water was freezing on the roof. They were all so brown it needed to be done.... Last time I buy a white car, that's for sure.
 
I had new spark plugs ready on the shelf so I started in that end.
Hadent done this work on a AUA before, but it was straightforward.
Using a hook to release spark plug caps from plugs and then lift away the caps with plastic cover.
_20210101_151128.JPG
 
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