DSAB: PRIMARY OAT SENSOR LOST

[AmphibFlyer]

My winds aloft arrow has quit working, and from time to time I see this message:  DSAB:   PRIMARY OAT SENSOR LOST.

Is it possible to tell from a log whether the fault is within the D-10A, or in the OAT sensor, or in the wiring?

(The wind arrow is THE most useful feature of the EFIS for a seaplane.)

 

[Dynon]

If you have just an EFIS-D10A (no EMS), then the OAT is connected to the magnetometer, and in that case, if you're not also getting a heading error as well, it's most likely either the OAT itself or the wiring between it and the magnetometer. I'd check the wiring between the OAT and the magnetometer first. Is it sensitivie to physical movement, or is there and obvious breakage or fraying?

 

[AmphibFlyer]

Thanks!  No EMS. It's a D-10A and the autopilot with AP74, and connected to a GPS.

I get a heading indication, but didn't think to note whether that's coming from the remote compass, or the internal one. I'm not sure how to check that. Is it indicated in DSAB Setup, or some such place? I haven't noticed any error message about heading or remote compass.

The wiring doesn't appear to be broken or frayed, but I haven't looked hard at it yet.

Is there any way to check the integrity of the OAT sensor--a resistance reading, or something like that?

I don't find the error message that I see ("PRIMARY OAT SENSOR LOST") in the D-10A installation guide, but there is "OAT SENSOR NOT DETECTED This alert appears when the EFIS has an OAT connected and then loses that connection for some reason. Either the EDC-D10A has become disconnected, or the OAT sensor itself has become disconnected from the EDC-D10A."  Is that the same thing, just worded differently, or is it a different error?

Does "SENSOR LOST" mean that the sensor is detected at first, but then later lost? Or not detected at all?

 

[Dynon]

If you have a more recent version of the EFIS firmware, the heading doesn't automatically revert to the internal when the external EDC goes away. To check, though, wave a magnet around both (aircraft headset earphones usually work well). One location should swing. That's the heading sensors that are active. If the EDC's connected, it disables the internal ones.

OAT test: With no power, you should see 10K between the red and blue wires, and between roughly 5-20K (temp dependent) between the yellow and blue wires.

On the error, I *think* that's a small discrepancy between the docs and the actual error.

 

[AmphibFlyer]

Thanks again! That's just what I needed to know! I'll check it out. =Don