Garmin c340 takes approx. 15 blocks before speed registers. Why and what can be done to fix this?

SOURCE: garmin c340

First, be sure you are outside, in the open when making this diagnosis. Some cars have metallic defrosting layers, which blocks the GPS signal. If, when outside in clear view, you still have problems, try this...

Have you tried a hardware RESET? The button is hidden behind the front panel, which snaps off by a fingernail slot located directly under the GARMIN logo on the front panel.

* Use caution removing and reinstalling the front panel... it's somewhat fragile... wiggle it a little to get it off.

Press where it says "Press to Reset", hold for a second or two. Charge the unit with the car cord or USB cable, then try to turn it on again.

Once you can get the unit to (hopefully) turn ON, you should run all updates (there may be several!) using Garmin's Webupdater. (Connect to computer with USB cable first.)

Hope this helps!!

Posted on Jul 18, 2008

SOURCE: speedometer appears to register 15 miles less than actual speed

If you have replaced your stock size tires with oversize aftermarket tires and wheels (17 inch stock wheels to 22 inch wheels, etc) you need to have the computer reflashed to compensate for the larger tire size. Larger tires turn slower to maintain the same groundspeed, giving a false speed reading.

Posted on Apr 10, 2009

SOURCE: update 2009 maps into c340 how to

The Garmin Streetpilot C340 is discontinued, so there isn't much support for it. You can find some updates at
https://buy.garmin.com/shop/store/downloadsUpdates.jsp?product=010-00401-20&cID=164&pID=290

But no free map updates.

Posted on May 13, 2009

SOURCE: Garmin C340 will not take a charge.

The internal battery needs replacement. You can change it yourself if you are comfortable with soldering, and are mechanically inclined.
Search the internet for:
"Replace battery Garmin c330" You'll need a small Philips head screwdriver to open the case, and to remove the battery holder. It is tricky to put the antenna back, so be careful.

Posted on Jul 20, 2009