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Support FAQ

If you are having problems getting your car connected to the server, the following FAQ may be of help. The vast majority of problems are caused by typos or mis-understandings in the vehicle ID, usernames and passwords to be used. Review the user guides and please triple-check all settings. You can also use the MODULE? and SERVER? sms commands to read back the configuration you have set.


  1. On 5th April 2016, we changed the server tmc.openvehicles.com to a new IP address. Please make sure your Server IP parameter is 'api.openvehicles.com' for both vehicle modules and Apps.

  2. Firmware

    Make sure you have the latest firmware and it is the correct build. Different builds have different features even though they may share the same version number (for example, the production build doesn't include the Advanced Charge Control feature, but the Tesla-Roadster specific build does).

  3. VehicleID

    This is how the OVMS server identifies your car as distinct from other cars. You get to make this up, but it has to be unique from any other car. If you participate in a Social Group, this will be the name displayed next to your car on the map. VehicleID must contain only uppercase letters and numbers.

  4. OVMS Module Password

    Normally, the OVMS module uses callerID to recognize a cell phone you register as authorized to communicate. This password enables you to use any cellphone or SMS service to send text messages to the OVMS module. The default is “OVMS,” but we strongly recommend you change it to something of your own choosing.

  5. OVMS Server Password

    This is a shared secret between the OVMS server, your car, and your smartphone App. You get to make this password up.

  6. OpenVehicle Username & OpenVehicle Password

    These are the credentials you use to log into the OpenVehicles.com web site. You probably already used them to log on to order your hardware module. You get to choose your OpenVehicle Username and OpenVehicle Password.

  7. SIM Card

    3G SIM cards should be compatible (but note that OVMS uses a quad-band 2G radio 850/ 900/ 1800/ 1900 MHz). Please note that most cellular providers require a minimum balance (perhaps US$5-10 or so) in order to use GPRS functionality.

  8. Cellular Network APN, Cellular Network Username, & Cellular Network Password

    Your cellular carrier uses these to establish and authorize the GPRS (internet) connection from the OVMS module to the cellular network. You should ask your cellular provider for these values when you purchase your SIM card.

  9. Triple-check credentials

    If you are having trouble connecting, please triple-check your credentials (usernames, vehicle IDs and passwords). Simple typos or mis-understandings of what goes where are the single most common cause of connection errors.

  10. Vehicle Type

    The vehicle module supports several different types of vehicle. You set this with the MODULE sms message, or directly as parameter #14. The following vehicle types are currently available:

    TR - Tesla Roadster (v1.5, v2.0 or v2.5)
    VA - Volt/Ampera
    RT - Renault Twizy
    O2 - Generic OBDII
    TC - Think City
    NL - Nissan Leaf
    TZ - Tazzari Zero
    MI - Mitsubishi iMiev
    KD - Kyburg
    XX - Generic Tracking

  11. GSM/GPRS Switch

    The OVMS module includes a hardware switch that enables or disables the GPRS data mode, which is used by the smartphone Apps. The switch is on the main board (which is on top and smaller) along the inside edge. Sliding the switch towards the LED lights will disable GPRS data. Sliding it away from the LED lights will enable GPRS data. If you will solely be using text messages to communicate with the OVMS module, then you should slide the switch to disable GPRS data communication. If you will be using a smartphone App, then make sure the switch is set to enable GPRS data communication.

  12. GSM signal strength

    Move your car to an area of excellent GSM signal strength, to rule that out as a problem.

  13. LED Codes

    The OVMS module has two LED lights. When the OVMS module is connected to the car, it will go through a start-up sequence, which is reported through its LED lights. Firstly, the RED light will come on solid and the green light will blink the module’s firmware version as a set of 3 sequences, each separated by a pause. For example, 1.2.7 will be 1 blink then a pause, then 2 blinks then a pause, then 7 blinks). Then, the GREEN light will blink out a countdown of the boot-up sequence. Should an error occur, the RED light will blink out an error code. Note that in case of an error, the Green light will still be blinking its state concurrently with the Red light blinking out its code. For instance, if the SIM card has a PIN lock the Green light may be blinking 8 times while the Red light may be blinking 4 times. This will look like both Red and Green blinking 4, following by Red blinking another 4 (to make 8). You may want to hide light with your finger to help you count properly. Sometimes during bootup, the module will need to reset the modem. If this occurs, both the Red and Green lights will come on for as long as it takes to reset the modem, which is typically a second or two. This is nothing to worry about.

  14. GREEN LED Codes

    10 – Waking up the modem
    9 – Checking for presence of SIM card
    8 – Checking SIM card and lack of PIN lock
    7 – Initializing the modem
    6 – COPS initialization (trying to connect to a cellular tower)
    5 – GPRS Network initialization
    4 – GPRS APN is OK (Initialization complete)
    3 – GPRS Network call is made
    2 – GSM is Ready
    1 – GPRS is Ready.

  15. RED LED Codes

    1 – Lost signal
    2 – Cannot communicate with modem
    3 – SIM card is missing, not inserted properly, or not detected
    4 – SIM card has a PIN lock
    6 – COPS GSM lock could not be obtained
    7 – Error during GPRS initialization (might be temp related)
    8 – GPRS Network initialisation failed

  16. CAN Write

    By default OVMS is configured to only monitor the car’s state and not make changes. Some vehicle types require write access to the CAN bus, and this will also be required if you want to control car state (lock, unlock, start/stop charge, etc) for other types of vehicles such as the Tesla Roadster. You can enable the CAN Write feature by sending ams "FEATURE 15 1" from the registered cell phone. To disable CAN Write via SMS, send "FEATURE 15 0". CAN Write can alternatively be enabled via some of the smartphone Apps using the “Feature” setting page.


If all else fails, please send the output results of the following SMS messages to

support (at) openvehicles (dot) com
  • MODULE?
  • SERVER?
  • GPRS?
  • STAT
  • DIAG