Hi all,

I have a Garmin Drive 50LMT, and whenever I connect the charging cable to my car's USB port, it immediately goes into MTP mode. I.e it shows the screen with the orange icon showing the device connected with a cable. I have a lot of trouble trying to get it back to viewing maps.

Is there a hack or a way to permanently disable MTP mode, so I can just have it charging without worrying about losing my navigation while driving?

I have tried the official garmin cable, and a new expensive cable (which I saw suggested elsewhere online) but it has not made any difference. I am plugging it directly into my cars usb port, not via a charging device/cigarette lighter port.

Any advice would be greatly appreciated

The problem is not with the device or its settings, it's because you're using a USB data cable so the device wrongly detects that it's being connected to a computer. There is a hack to use one of those, however you should just use the Garmin charger supplied with your Drive 50 which it meant to be plugged into the car's lighter port.

Thank you B1ng0 - that's really good to know. Guess I'd better dig out that car charger and see how it goes. I had been using the usb port as it was in a more convenient spot in the car to run the cable.

Are you able to share a link to the hack so I can have a look just in case it's something that's going to work better? Thank you again for all your advice!

Garmin units have the miniUSB port through which they are connected:

• To the vehicle as a power supply
• To the PC as a mass memory

The difference (so the function) is in the mini-usb plug:

• Original GARMIN power cable has pin 4 connected to pin 5 via a 17.3 Kohm resistor
• Normal mini-usb cables on the market (used for the PC) have a resistance (connected as above) of 200Kohm, or even without any resistance (more frequent case)

Garmin unit, through its internal divider, is able to discriminate between the two cables and starts in Navigation mode (point 1) or in PC mode (point 2)
In case you want to use a cable purchased after-market as power from car cigarette lighter, from USB to PC or even power supply to home network (so not original from plug) and you want to get the same performance of the Garmin cable, you have to change a miniUSB plug and change the resistance from 200K to 18K (I recommend to weld a 20K in parallel so as not to run the risk of damaging the connector). Sufficient a resistance of 1 / 8W 5%

Required materials: resistance, cutter, heat-shrink sheath of suitable section to the cable, lighter, welder with micro tip (if adjusted much better)

I can confirm the hardware hack posted above indeed works. Further confirmation:

Code: Select all

http://pinoutguide.com/GPS/garmin_nuvi_power_pinout.shtml

There is also a messy procedure which may work with garmin devices using a generic USB charging cable:

• Plug the cable into the power source.
• Plug in the Garmin device which will start in PC mode.
• When it shows the computer tower icon, immediately unplug the usb and it should then switch from PC mode to normal booting.
• After it switches into boot mode, but before it's gone too far into the boot cycle plug in the cable again and it should continue to boot up fully into navigation mode.
• Repeat the procedure each time you disconnect the power.

It's ok for an occasional use but I think it'd get very annoying very quickly. So much easier to just use the original lighter charger.

B1ng0 wrote: It's ok for an occasional use but I think it'd get very annoying very quickly. So much easier to just use the original lighter charger.

Wow, absolutely! Here I was thinking it might involve a little bit of software coding or tricking the system, but this is a step up.
Thank you both for the tips - I had no idea the cables could differ in that way. I'll see how I go with the car charger, but I'm really glad to know that there is another option I can try if I want to - I do have a soldering iron, which I can dust off.

Thank you again for your advice, it is really helpful :D

Sent Via PM: Tue Aug 10, 2021 6:30 pm
From: maxderoswell
To: GarmanNuvi

Hello,
I try to mod my car by fitting a Garmin Nuvi 2597LTM directly under the dashboard cover, so not removable.
I wish keep the possibility to update this one.
I had placed the unit and use this cable

to have an access for the the lighter charger or the USB cord.
I have an issue because the unit doesn't show the video from the rear camera by using the BC30 cord.
With the classic lighter charger, the unit goes into PC mode before come back at normal.
Could you help me ?
Thank you so much.
M

maxderoswell wrote:I have an issue because the unit doesn't show the video from the rear camera by using the BC30 cord.

The BC 30 Wireless transmitter and power cable has to connected directly to your nuvi NOT through the cable you gave a link to.
I would use a cigarette lighter socket mounted behind the centre consul, also you will have to make sure your firmware is up to date before installing to make sure support for the Garmin BC30 Wireless Backup Camera is installed.
Future up dates will have to be done with a laptop & USB cable if mounted permanently.

With the classic lighter charger, the unit goes into PC mode before come back at normal.

"Classic" power cables are not wired the same as Garmin power cables explained in this thread

Hello,
thank you for this beginning of answer.
I can add some details.
I had de-solder the usb cable from the bc30 and I find a resistor of 5,72Koms between GND and iD (pin 4) wires.
I must keep my assembly like this with this middle cable, so do you think I just must add a resistor inside him ? What kind of value ?
Thank you so much.

maxderoswell wrote:I had de-solder the usb cable from the bc30 and I find a resistor of 5,72Koms between GND and iD (pin 4) wires.

That's how Garmin stop your device going into MTP mode when connected to the power cable.
I must keep my assembly like this with this middle cable, so do you think I just must add a resistor inside him ? What kind of value ?
Thank you so much.[/quote]
I don't know if this middle cable you bought can be both compatible with data transfer (Updating etc) and Powering & receiving the Video signal from the BC 30 camera. I would think Powering is primary as updating can be done annually.

I want to power my Nuvi 1300 from a dual port USB 12v lighter socket adapter but most of the time when I connect it to that with a normal Mini B USB cable the silly thing switches to computer connected mode.

But *some of the time* it doesn't, if I turn the GPS on then plug in power, but some of the time even then it'll switch from showing the map to computer connected mode.

Is there a special cable that will make it NOT incorrectly detect that it's connected to a computer? Can I just cut open a cable and cut the data lines?

I found a way to prevent the Garmin Nuvi from entering PC Sync mode while you are charging it with USB.
Step 1: Turn off your Garmin.
Step 2: Connect it with USB and let it enter PC Sync mode.
Step 3: When it's in PC Sync mode, lock it using the switch (my Garmin Nuvi has it at the top).
Step 4: Disconnect the USB and then connect it again when Garmin isn't in PC Sync mode anymore (when the PC icon disappears and Garmin starts loading).
And that's it! Let me know if it worked for you. 

To Lenart,
Thanks for the description, but it did not work on my nuvi200.

In your Step 4 this is what happens in my case:
After removing the USB cable from the nuvi200, the PC icon disappears and the unit starts normally. At this point I reconnect the USB cable. After a few seconds a large message pops up saying that the unit is locked (as it was done in your Step 3) and tells me to slide the switch to the left. The popup goes away after a few seconds and the unit shows the startup screen, showing 'Where to" the map icon, Setup etc. If I touch the screen, the popup will again cover almost the whole screen.

If I comply and slide the switch to left, the unit goes into PC Sync mode again.

Also, I think it is important to clarify that in Step 4, the USB connector has to be reconnected WHILE the unit is booting up, and NOT after it boots up.
Is there any other process you can suggest?

Hi, I have an old Nuvi 205W which I want to use after years of being forgotten in a glove box; my intention is to use it on a motorcycle where there isn't a cigarette lighter receptacle but a USB charging port. I had the same problem as posted here: the GPS went into PC mode and became useless...
Reading this post, however, I remembered a trick to avoid this situation; when you switch on the device with the remaining power in the internal battery, the Nuvi boots up and eventually shows the battery status icon; if you press and hold this icon, the device enters a service mode (a sort of information page and test functions); while in this mode, you can connect the GPS to any USB port, even a PC, then press the EXIT button at the bottom of the screen, and the Nuvi reboots in navigation mode. As simple as that.
You will need to charge the internal battery to a minimum level to perform this procedure. Hope this helps!
Sorry about my grammar, English isn't my first language...
Saludos.