lamba When a new Lambda sensor doesn't work

[OctaviaVRS2]

A curious issue here may attract the attention of the super techs here, so that's why I thought let's post it in case others have experienced the same.

 

Vehicle 2.0 TDI VRS SKODA Octavia mk2

 

A VCDS scan revealed that my Lambda sensor wasn't working, so purchased a new one and installed it. Rescanned after clearing codes and what? The Lamda sensor still not working but its in conjunction with manifold flap motor error (I know about that one already). Does anyone have any guidance what may be wrong and how I might easily determine if I have power to the sensor. I only have a basic multimeter. But first obviously is what reason that circuit may not be on. Then, if it is on, are any pins not working or giving appropriate output. I have a sensor with heater element but just wondering if there is some issue with mk2 TDI not using a heating element by any chance. As you can tell I am in the completely in the dark why a new sensor doesn't work.

[ApertureS]

17 minutes ago, OctaviaVRS2 said:

A VCDS scan revealed that my Lambda sensor wasn't working

Thats your first mistake - there is no diagnostic tool on this planet that is able to tell you your lambda sensor is faulty using the cars own diagnosis. 

 

The fault code may of stated a lambda fault was detected but this could be many things including:

Bad wiring

Bad ecu

Bad sensor

Erroneous readings coming in to the sensor

Readings coming in to the sensor being out of spec ]

 

The only and correct way of actually testing to see if your lambda sensor is faulty is to eliminate all of the other parts first. Whereas you have done it the other way round and replaced the sensor to eliminate that but have left the possibility of all the other faults

[OctaviaVRS2]

44 minutes ago, ApertureS said:

Thats your first mistake - there is no diagnostic tool on this planet that is able to tell you your lambda sensor is faulty using the cars own diagnosis. 

 

The fault code may of stated a lambda fault was detected but this could be many things including:

Bad wiring

Bad ecu

Bad sensor

Erroneous readings coming in to the sensor

Readings coming in to the sensor being out of spec ]

 

The only and correct way of actually testing to see if your lambda sensor is faulty is to eliminate all of the other parts first. Whereas you have done it the other way round and replaced the sensor to eliminate that but have left the possibility of all the other faults

 I see. Thank you for that guidance @ApertureS. I will look at wiring to see if I have any voltages coming, but as I understand it, that is a difficult test. I will need to see if I can find some way to eliminate wiring as a cause.

 

Where do readings coming into the sensor come from? I thought it was just the sensor creating 0.1 or 0.9 volts. I'll do one of those live tests and see if I can understand that. I knew this could be a nightmare scenario.

[ApertureS]

1 minute ago, OctaviaVRS2 said:

 I see. Thank you for that guidance @ApertureS. I will look at wiring to see if I have any voltages coming, but as I understand it, that is a difficult test. I will need to see if I can find some way to eliminate wiring as a cause.

 

Where do readings coming into the sensor come from? I thought it was just the sensor creating 0.1 or 0.9 volts. I'll do one of those live tests and see if I can understand that. I knew this could be a nightmare scenario.

It all depends on the fault code, what code are you getting and what tool are you using to read it?

[OctaviaVRS2]

7 hours ago, ApertureS said:

It all depends on the fault code, what code are you getting and what tool are you using to read it?

I'm using VCDS which is giving me P1116

[kentphil1]

 A place to start your diagnosis from, - http://wiki.ross-tech.com/wiki/index.php/17524/P1116/004374