[esi183]

Hi all,

I was wondering if I could ask for some advice about lambda values available on ISTA. I have a UK 2013 330d (N57B30), with around 130k miles, and have noticed that - despite many drive cycles as specifically instructed by ISTA, and indeed driving it for several thousand miles - I can never get the Air Ratio (lambda) value to display on the DDE menu, or in the 'Air Mass System Test' sub-menu which tests the lambda sensors.

I'm wondering whether it's caused by a software glitch that means the car doesn't recognise the drive cycles? In the DDE menu, the 'Number of drive cycles since error memory was last deleted' and the 'distance travelled since error memory was last deleted' always stays at 0, regardless of how long I've been driving after clearing the error memory (or not).

I realise that diesel engines don't instantaneously adjust to lambda values in the same way as petrols, however on these engines (as far as I'm aware), the lambda value is used to correct for overall injection volumes (mean quantity adaptation). I'm wondering whether this could be related to a recent worsening performance / fuel economy. I've recently had the car walnut blasted, and it otherwise doesn't have any telltale problems of other issues.

Can you guys see the lambda values successfully on your cars?

Thanks in advance for your help

[Enabled]

Has the car been remapped or any other modifications?


In ISTA, on the module map, click on the engine ecu (labeled DME sometimes, or DDE) and click call up ecu functions on bottom left. The use the tabs to bring up the diagnosis request, and log the various sensors you need.

The oxygen sensor is mostly used for emissions, it will not up-regulate fueling. Mass airflow sensor is used much more.

[esi183]

Originally Posted by Enabled

Has the car been remapped or any other modifications?


In ISTA, on the module map, click on the engine ecu (labeled DME sometimes, or DDE) and click call up ecu functions on bottom left. The use the tabs to bring up the diagnosis request, and log the various sensors you need.

The oxygen sensor is mostly used for emissions, it will not up-regulate fueling. Mass airflow sensor is used much more.

No - no remaps at all; car is stock.

When I am reading all the sensors in ISTA, and no matter what I do (in terms of drive cycles etc), the pre-cat Oxygen Sensor is always 'not available'. I realise it's not a major issue, but was wondering whether this would affect the 'mean quantity adaptation' for the injectors (where the car calibrates the average fuelling over all cylinders periodically). As I understand, this is based on Lambda readings from the oxygen sensors, but it's of course not realtime in the same way a petrol engine's fuelling is adjusted. Many thanks.