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Replacement Dynon MAP sensor

hydroguy2

Well Known Member
Starting my condition inspection this weekend, and 1 thing on the list is replace the MAP sensor. I have a Dynon and can get one from them...but I seem to recall a post saying GM sensor is the same and locally available.

So anyone have a part number or other info about a direct swap vs the Dynon part?
 
easy enough

Hey Hydro:

I used Google and looked at the inages to get the right part. I recall about $35 at O'Reillys?

Carry on!
Mark
 
FYI

Brian,

I don't know how this thing is oriented in the installation, but it looks like the same sensor used on a CAT 3406 PEEC in the '80's. It was positioned with the hole facing up and would get a drop of water in it and freeze, resulting in failure. (driving -flying- in rain)

Positioning it hole-side-down resulted in dropping failure rate to - - -never.

Good luck.
 
Perfect thanks everybody.

VAF is great source of fast info. I'm sitting here prepping for my borescoping this afternoon, so can't get to far from a bathroom. :eek: but still able to make progress on Auroras inspection.

Oops was that TMI :p
 
Some more numbers that can help:

GM Part #16254539

Napa PN: CRB21963
Autozone P/N: Wells SU129
Shucks/Kragen/Checker/AC Delco #213-361

Make sure you get it via part number, not just looks. There are 3 parts that look identical, but only one works.
 
Last edited:
thanks for the additional information. Originally, I had planned on ordering one from Dynon....but I'm a procastinator (level II) and am under the panel this weekend so figured there was a local option.
 
Well, that was chore for no gain. None of the numbers above worked for me at the local autoparts shops....except the number 12247571. I was able to cross this number over at O'Rielly autoparts to the below sensor.



The bad news is....the MAP reading on my Dynon on the ground is exactly the same. :( Haven't flown yet, but makes me wonder what's next.

I replaced the Dynon sensor because it appeared I had a 0.3-0.4 error.
 
Brian,
I see you are in Montana, which is not at sea level. The MAP and BARO setting should not match unless you are at 0 MSL. Are you factoring this in?
 
Yes. I never knew there was a problem until several people told me there is no way my MAP could be as high as it is. Apparently I was showing higher than physically possible. So I ran a test per Dynon and they said "yep you're to high and need a new sensor." no way to calibrate it.

So new sensor didn't change anything. Might have an issue with my D180.
 
These sensors are very crude in terms of "they are all the same output" because near enough is good enough.

We see MAP in 1/10" increments and they have a +/- 0.3 - 0.5" accuracy out of the box. I reported this anomaly to Dynon about 4-5 years ago, and in later software versions came a choice of sensor with an offset that you can select to trim out this visually annoying error.

On a D120/D180 that option does not exist (that I am aware of) so you just live with a slight error and ignore it. Millions of these sensors world wide, and it affects nobody. They are not altimeters :D

Hope that helps.

PS.....yes keep water out of them
 
Reviving an old thread...

We were cruising along to Oshkosh and I got a high manifold pressure reading.
map-M.jpg


No change in the engine's running or performance, so it didn't suddenly grow a turbocharger. :D

The Dynon MAP sensor just has the 3 wires connecting it to the EMS unit.
IMG_3926-M.jpg

Power (red/white), MAP (green/red) and ground (black).
Since the Dynon EFIS got the MAP sensor output, and alerted me, it would appear that the sensor is likely having issues.
We also experienced this briefly as we were in the long line to depart Oshkosh. The rest of the trip it was perfect.

I did also note that my Electronic Ignition Commander was offline. I used the VP-X to recycle the power to it and everything came back online. We did get a few drops of water from the morning dew getting under the tip up canopy, but the location of this MAP sensor is away from that and right up near the firewall. Probably a coincidence? The P-mags share a connection with the MAP line that comes off the #3 cylinder, and gets tee'd off to the MAP sensor and the P-mags. The EIC showed the same advance angle, and no changes noted on the EGT/CHT's during this event.

So, am I correct in assuming the sensor needs to be replaced? Is that how these fail with a high reading?

Looks like this is a standard automotive part, so hopefully I can find one with the part numbers in this thread for less than the $90 that Dynon currently wants.
 
Reviving an old thread...

We were cruising along to Oshkosh and I got a high manifold pressure reading.
map-M.jpg


No change in the engine's running or performance, so it didn't suddenly grow a turbocharger. :D

The Dynon MAP sensor just has the 3 wires connecting it to the EMS unit.
IMG_3926-M.jpg

Power (red/white), MAP (green/red) and ground (black).
Since the Dynon EFIS got the MAP sensor output, and alerted me, it would appear that the sensor is likely having issues.
We also experienced this briefly as we were in the long line to depart Oshkosh. The rest of the trip it was perfect.

I did also note that my Electronic Ignition Commander was offline. I used the VP-X to recycle the power to it and everything came back online. We did get a few drops of water from the morning dew getting under the tip up canopy, but the location of this MAP sensor is away from that and right up near the firewall. Probably a coincidence? The P-mags share a connection with the MAP line that comes off the #3 cylinder, and gets tee'd off to the MAP sensor and the P-mags. The EIC showed the same advance angle, and no changes noted on the EGT/CHT's during this event.

So, am I correct in assuming the sensor needs to be replaced? Is that how these fail with a high reading?

Looks like this is a standard automotive part, so hopefully I can find one with the part numbers in this thread for less than the $90 that Dynon currently wants.

cant get water in the sensor if there is a hose on the end (internals are potted in epoxy) and they typically use weather pack connectors, so no likely effect there. They are a transducer with chips in them, so they can and do fail. Not sure there is a typical failure mode.
 
Map sensor mounting

FWIW- & not saying this is your issue, I always mount the sensor on the engine side of firewall as high as possible & above the cylinder it was tapped into ;)
They normally go into the engine bay of an automobile.
 
Just a followup on my post above about the possibly failing MAP sensor.

The Electronic Ignition Commander (EIC) shares a wire with the MAP sensor. The MAP sensor gets a ground, +5V power and the output goes to the Dynon EMS unit AND the EIC. The MAP sensor is not failing, but I think something weird is being introduced into the circuit by the EIC unit.

First thing I did was to move the EIC's power from my fuse block over to a dedicated circuit on the VP-X Pro. I previously had a VP-X Sport and was a bit short on available circuits. This was pretty easy to move the one power wire off of the fuse block and on to one of the new J8 connector circuits available on the VP-X Pro.

This allows me to cycle the EIC on/off from the EFIS without turning off the other fuse block circuits (mostly LED lights, ELT and the Hobbs meter).

Second thing I did was to play around with enabling and disabling the MAP sensor feature on the EIC. This is an optional feature, and I've never relied on the EIC for reading my manifold pressure. However, with the MAP sensor feature disabled, the EIC would still affect the MAP reading on the Dynon EMS.

Third thing was to just remove the MAP sensor wire from the connector on the EIC. Problem solved.

Here are a couple of videos showing the issue.
https://www.overthehills.com/RV-9A-Project/TDA-videos/n-FkNkXq/i-zcJKfXr/A
https://www.overthehills.com/RV-9A-Project/TDA-videos/n-FkNkXq/i-NvL6QBQ/A

If anyone else has seen something like this, post your experiences here.
Maybe the EIC is failing?
 
Maybe the EIC is failing?

Yet another follow up post to my previous follow up.
In the several months since de-pinning the MAP sensor wire to the EIC, the EIC continued to have a variety of intermittent issues, then it eventually went dark. I pulled the unit out and found that the 15 pin D-sub connector that was soldered onto the back of the unit had over time fatigued enough of the pins so they were no longer making contact. I could see daylight under the connector where the pins were soldered into the PCB board.
I bought a new female 15 pin D-sub PCB straight connector, soldered it on and problem solved. The old connector was not physically supported very well, and the vibration and weight of the wiring connector over 10 years of flying finally broke the very narrow pins. I added some longer stand offs to the D-sub connector and now it is much sturdier.
 
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