As part of the Crosswalk K-12 solution, this blog outlines UniteGPS’ process for ATRACK AK11 GPS device installation. Devices will be mostly plug-and-play using the J1939 port beneath the dash of each school bus. Some vehicles, especially older ones, will not accept a continuously connected J1939 device. This will create errors with the proper function of gauges. Keep in mind that this can be caused by resistance in the J1939 wiring where resistance is not equal to 60 oms. In this case, you don’t need to hardwire these vehicles.
J1939 cable connection
To begin the ATrack AK11 GPS device installation, first plug one end of the J1939 cable into the rear of the AK11 and the other into the J1939 port. Place the device in the center of the dashboard without any obstruction to the sky. Please see the picture below to ensure proper location of the AK11 during the installation process.
Rear Panel of AK11 – I/O for Hardwire, DLC for Direct Cable, Serial, USB and External Antenna. You really only need the external antenna when the AK11 is installed without a clear view of the sky. Otherwise, the device has an internal antenna and will work perfectly, as long as the device has a clear view of the sky and is not within 6″ of any window frit.
Connect one end of the multicolored wire (below) to the I/O port in the rear of the AK11. Basic installation only requires three wires; Black (ground), Red (power), Yellow (ignition). When the vehicle is at rest, the voltage will be near 12V at the ignition and when the vehicle is turned on the alternator is engaged and voltage increases substantially. The device is continuously monitoring the voltage level at the ignition and senses when the vehicle is turned on or off based on the voltage change at the ignition wire. Therefore, you must properly connect the ignition wire to the yellow wire for the device to function properly. The remaining multicolored wires can connect to other I/O triggers.
IMPORTANT: Your device has been preset with a program configured to the J1939 CAN. However, many NEW school buses continue to be sold using the old J1708 configuration. In this case, you may see an error message or other readings on your dash or issues with the engine control unit data. We can correct these issues by sending a new program via cellular to the device. Specifically, we ship OBDII devices with the correct program so errors are unlikely to occur. If you reassign a device to a different vehicle, however, then you also may run into error codes with the OBDII. If this happens, we have a program that will convert the device to read OBDII, so just give us a call and let us know.
Extra reading: Check out how school districts across the country integrate data into the Crosswalk K-12 transportation solution with UniteGPS!