Dynon/Advanced Service Bulletin - Kavlico Pressure Sensors

[Dynon]

As an organization of engineers and pilots, we at Dynon and Advanced aim to promote safety-enhancing technology, and we constantly monitor our fleet and support data for issues that arise. To that end, Dynon and Advanced have been investigating a rare but important issue that affects the Kavlico pressure sensors that are often installed in aircraft equipped with our products, and we want to ensure that this community is aware of it.

Although we don't yet have all of the answers, we're publishing what we know, asking you for your assistance and reports, and will have a product improvement that will be available for most applications in the coming days.

We'll let the bulletin speak for itself, as it has the comprehensive background, technical information, and steps for Dynon and Advanced customers to take. Please read the bulletins available here (the content is identical):

https://dynonavionics.com/bulletins/support_bulletin_050620E.php
https://www.advancedflightsystems.com/service-bulletin-050620a.php

 

[maartenversteeg]

Thanks for this information. One general question regarding the suggested new Kavlico sensors. Do these new sensors have the identical interface (5V supply) and interface plugs (pinout) that connect the sensor to the aircraft harness and the Dynon EMS module? So are these basically plug in replacements?

 

[Raymo]

Great question, @maartenversteeg

Please let us know when the new sensors are available to order.

 

[djones]

The new sensors share the same connector, wiring, etc. We do have a new sensor file which includes new sensor characterizations for the new sensors, but they are identical to the characterizations for the old sensors and were only done to include the new part number of the new sensors. So essentially if you replace an old 150 with the new one, it just works. Same for the others, but since we now use the 150 psi sensor for everything above 15 PSI, like fuel injected fuel pressure, you will need to change the sensor type in sensor input mapping. We are working to have the new sensors ready to sell and should be available soon.

 

[maartenversteeg]

Thanks for the reply, that makes upgrading much easier. Changing the sensor configuration is not a big issue, but redoing wiring is much harder. With regard to using the single 150 psi for all the measurements above the 15 psi range. This comes at a price of reduced resolution, when you are only measuring a lower value like a fuel pressure of nominal value around 43 psi, I assume that with these sensors that the measurement resolution is still sufficient to monitor the fuel pressure behavior?

 

[djones]

The new 150 PSI sensor is extremely accurate down to pressures around 6 pounds, hence the need for the 15 PSI sensor. During testing we actually discovered the new sensors to be more accurate than the sensors they are replacing.

 

[GoneRVCrazy]

The Dynon Service Bulletin indicates the replacement 150PSI Kavlico sensor has a stamped part number of P255-150G-EA4. According to the Kavlico P255 data sheet the part number should be P255-150G-E4A (i.e. the A is on the end). Here is a link to the Kavilco P255 data sheet:

Sensata Technologies: Sensing is What We Do

cdn1.kavlico.com

Thanks for clarifying.

 

[djones]

Thanks, we fixed the service bulletin.....E4A is correct.

 

[Barron]

The new 150 PSI sensor is extremely accurate down to pressures around 6 pounds, hence the need for the 15 PSI sensor. During testing we actually discovered the new sensors to be more accurate than the sensors they are replacing.

I installed the new 103755-000 V2 Kavlico and am getting high fuel pressures (7.3) in my RV12 912ULS. I set up a mechanical guage and it appears to read ~1/2 of what i am seeing on my Dynon EFIS (both runing both pumps and electric only). The setup menu shows a Kavlioc 15psi (101690-000). does this need to be modified with the new sensor?

 

[djones]

If you replaced a 15 PSI with the new 15 PSI, the old sensor file should still work fine. The new sensor file only has the correct part number for the new sensor, the rest of it is the same. Can you verify the sensor part number on the label on the side of the sensor for me and give me a call Monday to get to the bottom of this

 

[Barron]

I really appreciate your response... there are a number of issues i am encountering anyway we can chat ? 206 255 6636

 

[Barron]

Part # P255-15G-E4A H2919







g-