FAQ

MyVoltControl:

  1. I need to buy an OBD adapter. How do I decide what to buy?
    • Below I’ll give you our suggestions, ordered by first-choice to last-choice. But first, there are four things to consider that are at a “higher level” than those choices.
      • The adapter must indicate that it supports your type of phone (eg, iOS/iPhone for MyVoltControl).
      • The adapter must be “Elm 327” compatible. You’ll often find this information only in response to questions asked by perspective buyers. There are five brands to avoid that are definitely NOT Elm-327. Those five are:
        • BlueDriver
        • AutoPhix
        • ThinkDiag
        • Autel
        • TopDon
        They only work with their own apps and nothing else.
      • Before you buy an adapter that connects thru WiFi, make sure your phone/iPad will be able to make a celluar data connection, at least briefly, while you make whatever In-App Purchases you need for the functions you want to use. If you want to use an iPad without the cellular chip, you won’t be able to use a WiFi OBD adapter at all. If you want to use an iPhone, it won’t normally need a celluar connection, but perhaps you can swap in a sim card from another phone long enough to make those In-App Purchases if you want to buy a WiFi OBD adapter.
      • While certainly not a requirement, if you want to use the My Volt Afterblow function in this app, you must select an adapter that supports the SWCAN (aka GMLan) bus (a subset of the function of the OBD system). Such an adapter must also support the “ST” command set, in addition to the common “AT” command set. Functions added to MyVoltControl in the future might also require SWCAN/ST-commands support. There are very few OBD adapters that support this bus and command set. Those that do will be more expensive.
    • Here are our recommendations:
      1. The OBDLink MX+ is the best, but it is more expensive. (Supports SWCAN.)
      2. The OBDLink CX is also a good choice. It’s a BLE device that provides security. It does cost more than some others. (NO SWCAN.)
      3. WiFi adapters that provide a secure network (eg, require a password to connect) are the third choice. Most WiFi OBD adapters do not require a password. Note that any WiFi adapter will be more difficult to set up initially, and be aware of the need for a temporary cellular connection as mentioned above.
      4. Most Bluetooth-Low-Energy (BLE) (aka Bluetooth 4) adapters are, by design, not secure. (The exception to this is the OBDLink CX adapter mentined above.) Not-secure BLE adapters should not be left plugged in to your car because anyone who can get within bluetooth range of your car can connect to it and cause mischief. If you must choose between a not-secure BLE adapter and an unsecured-WiFi adapter, you’re better off with the BLE adapter.
      5. Unsecured WiFi adapters don’t seem to work as well as the adapters listed above, will be more difficult to set up initially, and also provide no security. Be aware of the need for a temporary cellular connection as mentioned above. Don’t leave them plugged in to your car when someone can get within WiFi range of your car.
      6. In our experience, it’s probably best not to buy an adapter that normally sells for less that about $30 (U.S.). Cheap adapters often don’t properly implement the Elm 327 spec and may interfere with the operation of the car’s communication bus. Since I mentioned two specific brands of adapters on the high end, I’ll also mention two at the low end (cost-wise) that are known to work well. These are the “VeePeak BLE” and the “LELink BLE”. There are many others that will also work well.

  2. I got a new phone (or had to un-install the app on my phone) and now that I’ve installed MyVoltControl again, it says that I need to buy the “In App Purchases” again. That ain’t right!
    • That wouldn’t be right! In fact, I’m quite sure that it wouldn’t let you buy those things again. For pretty much any app that supports in-app purchases, you’ll find a button that says something like “Restore Previous Purchases” for just this circumstance. In MyVoltControl, open the Menu and go into the “In-App Purhcase” screen. At the bottom of that screen you’ll find the “Restore Previous Purchases” button. Press that (even when you’re not connected to your car) and you should be all set.

  3. MyVoltControl connected to my Bluetooth Low-Energy adapter with no problems. Now I’m trying to use it with another BLE adapter and MyVoltControl can’t find it.
    • Once you’ve started to use an adapter, MyVoltControl continues to connect to that (since it is quicker than searching for new adapters each time). You can override that behavior with a “long press” on the Connect button. This will bring up a small menu that lets you ask for a full scan for devices.

  4. The My Volt Diag screen shows the results of several tests, but how do I know what values are “good” and what values indicate a problem?
    • We’ve added an “Info” icon button at the top-right of the Volt Diag screen to give you what information we have. We don’t collect information from our users so we don’t really know what value most people are seeing, but that info page will show you what values your car probably had when it was new, and what we’ve learned are probably bad values.

  5. I see that I can now run MyVoltControl in split-screen mode on an iPad. Can I run another OBD-related app in the other screen portion?
    • No, unfortunately you can’t. OBD adapters have only one “channel” and so they can only communicate with one App at a time. (And to answer the question you’ll probably ask next: You also can’t use two OBD adapters with an OBD splitter. They would both be using the same “receive address” and so their communications would be intermixed and unusable.)

  6. Why am I getting a “Failed to Connect” or “Connection timed out” message?
    (Refer to “Connection Help” in the App menu for detailed instructions.)
    • Is the OBD Adapter connected to your phone as seen in Settings? (Not expected to be seen in Settings for BLE adapters.)
    • In the App, did you select the right type of adapter (MX+, BLE, or WiFi) in the Menu?

  7. I am using a WiFi OBD Adapter. Why am I getting an “Unable to connect to ITunes” message, or am unable to access some of the Menu information?
    • The most likely cause is that you didn’t complete steps 7 thru 12 in the WiFi section of the “Connection Help” documentation from the App menu.

  8. I’m getting a message that says “Input Stream is receiving too much data…”. What can I try?
    • The most likely cause of this error message is that another app that uses the OBD adapter is trying to use it at the same time as MyVoltControl. This isn’t really something that we can share. Make sure to fully “terminate” any other OBD-related apps before you connect with MyVoltControl. (Putting that app into the background isn’t sufficient.)
    • If the message persists, please use the Contact page to report it to us and we will try to determine the cause.

  9. MyVoltControl isn’t remembering my selection for the “Enforce SOC Limit …” in the My Volt Hold function.
    • Actually it does remember it…for 12 hours. After that, the option is reset. If you want to turn it on again, please again agree to the disclaimer.

  10. I set a high “SOC” value in the “Auto-Hold” section of the Volt Hold function, and while it started “Hold” mode right away, the “target SOC” was not the value I entered.
    • That is correct. The value you enter is NOT a target value. Whenever the current SOC of your battery is below the value you enter, “Hold” mode will be turned on. The SOC at the point that it was turned on is the target value (although we subtract one percent from that when the SOC is very high). If you put in “99” for instance, you car will auto-engage Hold mode immediately, and the “target” will be approximately whatever the SOC was at the time it was engaged.

  11. Is there a way to see what values are used in calculating the efficiency numbers shown in the My Volt Hold function?
    • Why yes, as a matter of fact there is! That information is shown at the bottom of the About page, accessible from the Menu. Let me give a brief explanation of what the numbers mean.
      • BO: Distance traveled (in kilometers) with the ICE off (battery odometer).
      • BE: Energy used to travel that distance (in watt-hours)
      • IO: Distance traveled (in kilometers) with the ICE ON (ICE odometer).
      • IF: Fuel used to travel that distance (in liters).
      • IE: The unresolved amount of change in stored energy while the ICE was running (ICE energy). A negative number indicates that the battery SOC has increased.
      • IRO: The actual distance that was driven after the ICE was turned off from what was IE. (ICE resolved odometer.) The energy for this distance came from fuel burned.
      • IRE: The amount of energy that was previously shown in the IE field before it was resolved to IRO. If all excess energy has been resolved to distance, IE will be zero. (If IE is non-zero, it means you didn’t drive long enough after turning the ICE off for all of the energy to be resolved.)

  12. Cool! But that’s kinda confusing. How are those numbers used?
    • Calculating electric efficiency from BE/BO is straightforward and is left as an exercise for the student.
    • Were it not for the change in SOC while the ICE is running, calculation of fuel efficiency would also be straightforward (IO/IF or 100*IF/IO). The fuel number (“IF”) is used as-is. The IO number is adjusted as IO’ = IO + IRO – a1.
    • The “a1” (above) is an estimate of the distance that will be driven from the remaining IE. It is estimated based on IRO/IRE if IRE is non-zero, or on BO/BE if it is. (If BE is also zero, we use 1km/150wh.)

  13. Great! But the numbers I get don’t agree with what the car dashboard said.
    • First, keep in mind that the numbers reported are only measured while MyVoltControl is displaying the My Volt Hold screens. If you took a phone call, the distance/energy/fuel used while you were on the call isn’t recorded by the App.
    • Perhaps you pressed the Reset buttons on the Efficiency page?
    • The numbers shown on the gauges are updated only every ~20 seconds. Perhaps they were not quite caught up with the About page data (but that’s not likely to matter much after you’ve driven for a while.)

OBD Explorer

  1. OBD Explorer connected to my Bluetooth Low-Energy adapter with no problems. Now I’m trying to use it with another BLE adapter and OBD Explorer can’t find it.
    • Once you’ve started to use an adapter, OBD Explorer continues to connect to that (since it is quicker than searching for new adapters each time). You can override that behavior with a “long press” on the Connect button. This will bring up a small menu that lets you ask for a full scan for devices.

  2. I tried the Share option for sharing the log, which brought up the small share window. Then I changed my mind. How do I cancel a share?
    • Just continue thru (by pressing the blue Share button) and you can “x-out” of the screen that is shown next.