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Garmin 430 message "No GPS"

AlexPeterson

Well Known Member
I ran into something on the 430 that I hadn't seen in the 8 years I've been flying with it. I powered up, self check ok on the 430, called for clearance and taxied a very short ways to 09. Ground checks ok, but as I was taxiing from the runup to the runway, a big yellow "No GPS" message splashed across the 430's screen. It had successfully resolved position prior to this for the short taxi out. Anyway, I decided since it was a local flight I'd proceed (wow, what if I had had to use a vor to get back home, or worse yet, my eyes!). I ignored the complaint, and took off. The next time I looked down, at about 100' agl, it was back to normal.

I've seen raim warnings, but not an outage (or whatever it is called). Anyone else seen this?

I'll dig through the manual to see what it says also.
 
Have you ever had the internal battery replaced? I am about 30% sure that I got that message as part of the buldup to "you need a new internal battery" a year or so back....

Paul
 
I have had a couple of those messages. Once while in actual IFR!

I spoke with Stark Avionics and they claim that the location of my WAAS GPS antennea is the problem. I have it mounted under the cowling. Have others experienced this?
 
Jims reference to this link....

Something else to consider, especially if the problem persists or worsens...

http://www.vansairforce.com/community/showthread.php?t=46981&highlight=unexpected+solution

.....is very impotant indeed.
Although I have never seen it happen to an aircraft system, it can really be an elusive gremlin in auto systems. I am a professional auto tech of 35 plus years, and whenever I have an electronics intermittent to deal with, job one is to verify a clean DC output. Ripple, or the superimposed unrectified AC current being delivered by a defective alternator is seldom tolerated by any of the onboard electronics if it exceeds .050V or so. Problem is, most folks test for this without a proper load on the rectifier. Ripple, in most cases, is worse at higher current outputs.
Check for ripple can be done easily. Load check your battery per the manufacturers reccomendations, or use a Midtronics capacity tester to ensure that your battery is in top shape. A shorted cell can exasperate the ripple test, so it is important to make sure the battery is not at fault. DO NOT ASSUME that the battery is good just because you just bought it. Test it!!!! warm up the alternator, and apply as much load to the electrical system as you can. Just turn it all on. Check your DC voltage at the BATTERY TERMINALS with a digital VOM. Check your specs, but it should be roughly between 13.75 and 14.25 DC Volts. Switch to AC Volts position. You should have less than .050 AC Volts at load if the rectifier is healthy.
It's a quick check that has saved me many hours of diagnosis that would have proved fruitless.
About twice a year I get a car in that has had many many dollars spent on it in attempts to solve an unusual electronic circumstance. I have found current ripples to be the cause quite a few times, and I attempt no further diagnosis until battery condition and ripple issues are eliminated as the cause.
So, you ask, what is the next most prevelant cause of electronics glitches? Well, actually,it is the most common problem. Poor grounds. You need to load test them as well.

Hope this helps,
Chris
 
Thanks for the replies

Great tips - thanks.

Chris - I will bring my voltmeter to the airport and check for an AC signal on top of the 14v. The alternator has 1125 hours on it, and I happen to have a brand new spare sitting on the shelf.

Paul, I liked your confidence level! Internal battery about 3 years old (waas upgrade).

GPS (waas) antenna on top of fuselage, and hasn't moved.
 
GPS Position Lost

I too have a 430W that was updated when you could get it done for $1,500. And I also get the "GPS Position Lost" flag about every other flight. It usually lasts from 5 seconds to 15 seconds, then resolves itself. I thought that the problem was that the antenna cable was not the full 14' or 15' that Garmin specified and that we were overdriving the receiver. So I recently had Stein make me a new cable of the correct length, but I still get these alerts. The antenna is mounted on the glareshield, inside the cabin on my slider RV6, looking straight up through the windshield. I hadn't thought about the internal battery possibility, but I'll pay more attention now.
 
Update 10 months later...

Well, my 430 has not mis-behaved since I made the original posting on this thread - until last night. I was at 7500', been cruising around 30 minutes. A big yellow warning flashed on the 430's screen, something like "GPS lost, use dead reckoning". I switched it to the satellite screen, and waited. No satellite signals were present. I probably waited about 4 or 5 minutes with no change. I switched the unit off and back on. Again I went to the satellite page. After maybe 5 minutes, it started showing satellites again, and eventually found itself. Worth noting that the 696 didn't miss a beat, so no evil aliens disrupting the signal.

I've been meaning to look at the ripple voltage per the great post by Chris, but of course hadn't done it yet. It's on my list for next time to the airport!
 
430 No GPS

This happened to me several months ago and I traced it down to a EMI issue from a old VHF radio I have. Next time it happens put 430'on satellite page and start turning off other aircraft avionics or strobes etc.. likely to cause EMI and see what might clear it up.

C Jones
 
update, or "I hate intermittent problems"

Well, it is now a bit later - two years almost. The problem probably happened as described in the initial post about every 3 to 6 months.

I powered up yesterday, and the unit found location lock right away, as usual. I taxied out, and the gps lost message came up before takeoff. My 696 was quite happy, so it isn't a gps signal issue. I was all excited yesterday, because it simply didn't come back to life for the duration of a 50 minute flight. Excited because maybe I can fix the dang thing. I cycled power a couple times, but the satellite page simply showed nothing. Finally, some timer in the software says something to the effect "gps not responding". Duh. So, I planned to swap the unit with someone, to see if it the antenna or the unit. Of course, on the return flight, it worked the whole way... Grrrr.

Back when it was suggested by Jim, I loaded up the alternator to measure ac ripple, and it was something well below the 50mV range. However, when I rebuilt the engine, I did put a brand new alternator on, so I need to measure this one as well.
 
.....location of my WAAS GPS antennea is the problem. I have it mounted under the cowling. Have others experienced this?

Mine is under the cowl and the unit has NEVER lost a lock, unless I'm doing acro, in which case it recovers quickly.
 
I to have had the same problem and spoke to Stark Avionics, he thought it may be a Garmin software issue and was going to speak with them, will see..
 
I had similair issues with my 430W. I moved my antenna aft of the canopy and this helped, but it would still happen. I then had some kind of heat issue or at least the 430W thought so. It would warm up and then lose a GPS signal and eventually shut down. The repair shop could duplicate it on the bench. They called Garmin and they had them do a "Master Reset". They ran it on the bench several hours with no issues. I have been flying several months and so far it has always worked.
 
My gps antenna is on top, behind the canopy, and hasn't moved.

My only choice is to continue on, "hoping" that it fails for good. If it is some obscure software problem, this may not happen.

The odd thing about Saturday is that I powered it down several times in flight, and it simply would not find the satellites on powering up. I tried several times during the 50 minute flight. It certainly was not hot outside or in the plane. Then, flawless performance on the next power up about 4 hours later...
 
I saw this on a friend's 430W halfway through a 3 hour leg, lasted a few minutes.

Not hot, antenna on glareshield (RV-7), 696 kept a good signal throughout.

My friend had had it happen before, attributed it to antenna installation (short coax) and was temporarily using a small Gilsson antenna rather than the certified Garmin one.

It seems to be a common experience, although I don't think we've seen it with the 430W in our Cirrus.
 
I had the 430 lose GPS on my way back home from Oshkosh last year, and also this year... curiously over the same part of northeast Iowa :confused:

The antenna is on the glareshield with a very short coax to the 430.

My 196 portable kept GPS lock both times, but the autopilot is wired up to the 430 and when it loses GPS, it sure lets you know rather quickly with a left turn :p
 
Update

Well, very tentatively... my "loss of gps" messages might be due to a bug in the software.

Here are the observations: I was having fairly frequent "gps lost" types of messages this fall, as discussed in this thread. On one power up, I got a "terrain database error" or similar message. I reseated the terrain card, and the "terrain database" error did not occur when I powered up. Interestingly, I have not had the gps lost problem since then. If this continues, it seems that the gps loss problem might be caused by problems with the terrain database card seating. I can not imagine why the gps portion would be affected by this, unless some error handling bug causes it.

I will report back in several months. I know there are other threads regarding periodically reseating the terrain card. I will do this, and if I do not get the gps errors for about a year or more, it will be interesting.
 
The 430W does have a problem with RF interference. First as others have said the cable must be the correct length. I thought that was 30" but its been awhile (call Stein). Second if your antenna is too close to your EFIS like on your glare-shield you will have intermittent failures. The Antenna must be at least 18" from any RF source. I had the same problem with the correct length cable however my antenna was on my glare-shield. I moved it forward under the cowling and the problem went away.

Pat
 
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The 430W does has a problem with RF interference. First as others have said the cable must be the correct length. I thought that was 30" but its been awhile (call Stein). Second if your antenna is too close to your EFIS like on your glare-shield you will have intermittent failures. The Antenna must be at least 18" from any RF source. I had the same problem with the correct length cable however my antenna was on my glare-shield. I moved it forward under the cowling and the problem went away.

Pat

Thanks, got that covered. Antenna is on turtledeck, coax is correct length, checkout per WAAS install manual done regarding vhf transmitter interference. I'm convinced this isn't a gps signal to unit problem. The problem has occurred while flying along at altitude, no radio transmissions. The problem predates my aprs unit as well. Even if gps signal polluted, there would have to be a bug to prevent reacquisition once interference cleared.
 
I frequently get a similar message as well. Next time it happens I will record the exact wording.
 
gps signal loss

Did you figure out why you keep losing the gps signal?

I have been having similar issues. At one time I thought that the avionics shop did a master reset fixed it. It did for 1 1/2 years now it has been getting worse.

I have dual GRT with a gps in the GRT slave unit. I also have a DUAL bluetooth gps to my ipad. With the DUAL app I can view the satellites. If the GRT gps is running and watching the DUAL gps, when the Garmin 430 boots up the other gps's lose their signals.

The garmin usually doesn't aquire the satellites. If it does it only keeps them for a few minutes.

If I leave the cable disconnected from the Garmin 430. The other gps's will work.

If I power up the Garmin 430 with the gps cable connected, the GRT gps and the IPAD Dual gps will drop out. As soon as the Garmin 430 gps cable is disconnected or the unit turned off. The other gps's re-aquire.

Any ideas?
 
Alex, I've heard about your type of problem, where the 430 seems to shut down other gps's on board. That is not my problem at all.

The good news is it seems to be more frequent lately - I'm going to change out the coax cable to the antenna next week. If the coax was the problem, I should know in a few months, given the frequency (or lack thereof) of my problem.

I should mention Garmin has been kind enough to contact me regarding this problem, and have suggested I try the cable thing first. I received the new coax, and just need to terminate it and install it.

I'll report back.
 
i have found that reseating all connections along with a spray of corrosion x on the connectors is a good start. i have had intermittent electrical issues with my breaker connections that have disappeared since doing this.

once had a issue with gps signal loses and found a tiewrap keeping the 430 from seating completely. hate those electron issues. :rolleyes:

tough lookn bunch here!

img0254ak.jpg
 
This Solved My Problem with the 430

A few months ago my 430 displayed "GPS Signal Lost" at least once a flight. The GPS antenna is located on the cowling just in front of the canopy. Garmin said I needed a new antenna. Also, the engine was also running a little rough at times. During a spark plug inspection I noticed a broken ignition wire connector that was arcing to the plug. I repaired the connector and have not seen the "signal lost" displayed again after many hours of flying, and of course the engine is also running smoother. Apparently the high voltage arcing was interfering with the data signal to the 430.
A few months after this episode, I noticed a "Memory Battery Low" displayed on the 430. I replaced the memory battery and the 430 is now working as intended. Someone mentioned in this thread that these problems may be related.
 
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Follow up to 430W problems - solved!

I want to share a story about Garmin going above and beyond the call of duty in solving my nagging problem about which this thread was started.

About a year ago, I was contacted by their customer support manager about my problem. He had read this thread and wanted to help. We communicated a bit back and forth. I explained about why I kept waiting for the thing to finally quit once and for all, to avoid the back and forth (and $$) associated with intermittent problems. His suggestion was to first change the coax from the gps antenna. I did so, and the problem persisted. I was then asked to send the unit back for a free replacement of the gps board in the unit. This took under a week, but the problem remained. Garmin then sent a new antenna sometime this spring, and the problem has not recurred.

Kudos to Bill Parsons (Customer Service Manager) and the unnamed VAF'er who works for Garmin who just might have forwarded this thread last year...
 
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