So if you have been following my other threads you would know I'm pretty deep into a stereo system. I have been using OBD II dongle to watch some of the charge values and such through the tq app. Now my stereo system is dependent on the canbus system going to sleep and there is no active 12v trigger for anything. Last night I was doing some system changes upgrades and I noticed that the system was not going to sleep. This usually happens in about 10 minutes.

It took me almost 2 hours to figure out that that stupid OBD II dongle was keeping the car awake, and it was obviously an issue because immediately after I unplugged it the car started to charge the 12v System. Now this could be an issue with my own OBDII device but advise caution.

Some never go to sleep which is why this is recommended highly

OBDLink MX+

The OBDLink® MX+ is the top-of-the-line OBD II scan tool to use with forscan and comes with bluetooth. Get one here today and gain access to your vehicle!

www.obdlink.com

 

What never goes to sleep the car or the dongle?

 

Hyundai did put out a service bulletin and told their service techs to check for odb2 scanners or insurance discount trackers when the cars come in for work. Said they can cause canbus errors and then problems with or error codes showing up in modules in the car. If the car has these errors that and they can't be reproduced they are to ask the customers if they had one of these devices installed and removed it before bringing the car in.

The one I have is also auto off but I still keep it unplugged except for the few times I want to check something, then take it back out when I'm done.

 

Hyundai did put out a service bulletin and told their service techs to check for odb2 scanners or insurance discount trackers when the cars come in for work. Said they can cause canbus errors and then problems with or error codes showing up in modules in the car. If the car has these errors that and they can't be reproduced they are to ask the customers if they had one of these devices installed and removed it before bringing the car in.

The one I have is also auto off but I still keep it unplugged except for the few times I want to check something, then take it back out when I'm done.

Yup I remember when I was a tech I had guy come in with a no start, it literally was a bad interceptor gauge tied into the OBD II port, I'm not surprised at all.

 

From engineering standpoint....all dongles should be removed if not used ( unless you are confident that dongle is not interfering with can bus network sleep policy).

 

From a engineering standpoint the ob2 should sleep after 10mins. However I can give Hyundai (and other EVs) a pass because EVs have critical things to watch over.

 

 

I have both MX+ and for some reason switched to using an Vgate iCar Pro. I noticed a while ago when I pulled up the 12v monitor that I was suddenly seeing a constant drain of the 12v bringing it down to 11.99-12.02V. I realized that the older iphone 8 I had started using with the Car Scanner app was able to maintain a bluetooth connection at a longer range than my iphone 13 and Car Scanner kept the connection active and reading data. Once I made the effort to make sure Car Scanner disconneted it was fine. Now i've taken to only plugging in the ODB readers when I need them for say long roadtrips to monitor how things are doing (just out of sheer curiosity not because there are any issues).

 

I'm not aware of carscanner app firmware implementation for Obdlink MX+ to switch dongle to deep sleep.
Work around is to disconnect carscanner app, connect Obdlink app....cycle and disconnect, this way Obdlink app will initiate deep sleep for dongle....also while connected to Obdlink app check for dongle firmware updates.
If you have more questions please feel free to ask.

 

Do we know if the OVMS system has a sleep system or does it keep Canbus awake? I have one for my ioniq 6, will start unplugging after stopping for now but curious if it is necessary.

 

It was keeping canbus awake and keeping the factory head unit on (nothing was displayed) but it would obviously more power than fully sleep.

 

No obd2 dongle should be left in if not used.

 

Eh? They can be very handy. On my ICE Subie I left it in all the time and I used it all the time. No problems in 3 years. I haven't done the same with my new EV, yet.

 

So are these safe to use if you unplugged them after use before driving? What if you want to monitoring using the odb2 dongle when you are charging overnight to check for the overheating issue, is it still an issue? will it interfere with the charging of the 12v or main battery? Does this invalidate your car warranty at all?

 

Safe to use if you unplug them - yes
Monitor charging overnight - no problem and good idea
Will it interfere with the 12v or main battery - no (or there would be a billion people all saying DONT DO IT)
Does it invalidate your warranty - no (and again there would be a billion people all saying DONT DO IT)

 

Thanks

 

The OBDII port is always powered up, even when the car is off. So look for good quality adapter with automatic power-off mode - such dongle will not drain the 12v battery.

 

If it powers off automatically, how do i monitor the charge overnight ?

 

I just got a Veepeak scanner and managed to get it working with the Car Scanner app, so now it's my new toy. I'm still figuring out which sensors I should arrange on dashboard pages.

I really only got it to see if my car's AC inlet port overheats when I'm charging at 48 amps. But after seeing what else it does, I'll probably drive around with the scanner plugged in. I'll have to figure out a way to not leave it there afterwards.

 

I just got a Veepeak scanner and managed to get it working with the Car Scanner app

IOS seems to have a couple of apps named Car Scanner <something>. Which one are you using?

 

The OBDII port is always powered up, even when the car is off. So look for good quality adapter with automatic power-off mode - such dongle will not drain the 12v battery.

Actually, as I recall, the ODBII has two +12v pins, one switched with the ignition and one unswitched..so it just depends on which the dongle uses for power.

 

I have a wireless Apple Carplay dongle plugged into the USB port, is this a no no to leave installed? Had no issues yet.

 

I’ve an OBD2 reader too, and in the begining, I got to remove it after each trip. I forgot it once and I saw that it shut off after a while. Since then, I keep it in without any problem, even several days.

Only concern for me in the Ioniq 6 : if plugged, the cache that hides the fusebox can’t be put back. The dongle is to big for that. It’s the only thing.

 

I have a cheapie OBD2 reader and kept in my old subie for years. I have also used it in the Ioniq 6 for a few weeks at a time and had no problems with my 12v. But I am going to replace it with a better one because I need the BLE protocol to run ABRP in Android Auto. When I do I will make sure it has some security as well as a sleep mode because I will leave it in all the time.