liquid gauge. AFR not working

[m19lte]

As the title says.
I've recently installed a liquidgauge in my 02 s3 bam. It has worked fine for a few weeks, only this wkend it's not reading air fuel ratio ? Any ideas why ? All other gauges/readings work fine.
Could it be the oxygen sensor is knacked ? Car sometimes shows up a16500 code too !?! New Coolant temp sensor changed only 8month back too !?! Thanks

 

[<tuffty/>]

http://wiki.ross-tech.com/wiki/index.php/16500/P0116/000278

16500/P0116/000278 - Engine Coolant Temp. Sensor (G62): Implausible Signal

Do you have access to VCDS? it would need to be a full copy to log higher blocks such as 031 to check if afr is showing there... you can check block 001 too to see if lambda control is switching in...

I have a feeling that no readings get reported by the ECU until lambda control is active so you won't see actual AFR (which is what I believe Liquid reports on) until it kicks in... it is also plausible that the fault above could be preventing lambda control from switching in as lambda control is inactive during the cold start cycle and if the CTS is playing up then the ECU has no idea what the water temps are to switch control in

<tuffty/>

 

[m19lte]

Ahh makes sense. It was actually after cold start come to think of it when both faults appeared. I could get some logs done on vcds yes, but don't actually have it myself. Many thanks as per
Tuffty

 

[MUSH]

Does it start reading after a short while of driving?

Mine did exactly the same and a VCDS scan confirmed the lambda probe was faulty. It stops reporting when theres nothing to report lol. Was weird as i didn't have and codes that reported this either.

 

[<tuffty/>]

Depends what the circumstances are...

Adaptions and AFR control can be switched off for various reasons... some of which include no post lambda connected (if you have one), N249 valve electrically disconnected etc...

<tuffty/>

 

[m19lte]

Sorry folks only just noticed your replies !
Mine seems intermittent. Afr works sometimes then sometimes it doesn't !?!
I've even tried another known working coolant temp sensor and it still does the same !?!
When it does read Afr it shows up the 16500 code again saying coolant temp fault ?
any other ideas before I get it logged on vcds ? Bit of a pain for me getting it logged tbh ! Thanks

Oh all coolant temp. Oil temps so-on read fine on the liquid !