Bosch LSM-11 Lambda

[David Ferguson]

We've got the Bosch LSM-11 attached to LA1 on an ADL (with Lambda enabled) We are getting data with just a flat-line Lambda of 1.0 (pretty unbelievable). We tested with the sensor disconnected, and it then reads Lambda 1.5. Sensor is relatively new (it ran with good results for the first 10 hours or so), and we've confirmed the wiring is still OK.

Is this a default value from the WB Lambda software? What would it indicate? Is there an error or status channel available with more info?

[mikey]

Dave,
Something definitely seems amiss. The sensor should read between 0.75 and 1.50 on it's output voltage of 0-1VDC. It updates with a frequency of 100hz. Highly unlikely you would ever see a steady 1.00 with no fluctuation. Your ADL reading of 1.50 when disconnected sounds right. Mine reads 1.50 when power is on but engine is not yet started. I see small fluctuations at idle, +/- 0.02 from wherever I have "normal" a/f ratio set.
But looking back at your post, you only state the reading to 1 decimal place. If you're not reading 2 decimal places, change your display setup to show 100th's. It may be all that is "wrong". Other than that, not sure what your application is, but most engines would want to be closer to 0.90 steady state under full throttle. The Mazda 13B-MSP happens to hover around the same at idle.
I know you're pretty steeped in data acquisition, so hopefully I've not insulted you with being too basic in my explanation of my understanding.

v/r,
Mike

[David Ferguson]

Just to follow up, a new LSM-11 sensor fixed this. Seems like the sensor got a case of lead fouling.