If your LMU-364x seems to be failing, before contacting CalAmp about returning it, first try the following troubleshooting steps to make sure that something else other than the hardware isn't causing the problem:


  1. Make sure that the vehicle has a clear view of the sky.
     
  2. Check that the vehicle ignition key is in the ON position.
     
  3. Make sure that the device's label is facing the sky.
     
    LMU-3640s with internal antennas have a directional GPS antenna, and for best results, this antenna must be facing the sky.
     
    For an LMU-3641 with external antennas, check that the antenna connections in the back are secure and have a clear view of the sky.
     
  4. Check the status LEDs:
      
    • Ensure that the COMM LED is solid orange. This is what the LED states indicate:
       
      Condition
      		COMM LED (Orange)
      Modem off
      		Off
      COMM on - searching
      		Slow blinking
      Network available
      		Fast blinking
      Registered but no inbound acknowledgment
      		Alternates from solid to fast blink every 1 second
      Registered and received inbound acknowledgment
      		Solid

       
    • Ensure that the GPS LED is solid green. Here is a description of its LED behavior:
       
      Condition
      		GPS LED (Green)
      GPS off
      		Off
      GPS on
      		Slow blinking
      GPS time sync
      		Fast blinking
      GPS fix
      		Solid

       
    • Ensure that the VBUS LED is solid red. These are the VBUS LED conditions:
       
      Condition
      		VBUS LED (Red)
      VBUS off
      		Off
      VBUS on
      		On

       
  5. Make sure that the cabling isn't bent or constricted (and not cut!).
     
  6. Verify that the cable connecting the LMU (location messaging unit) to the vehicle CAN bus is not loose or broken.
     
  7. Verify that the LMU is reporting to CalAmp:
     
    1. In the CalAmp application, go to the Tracking screen to check whether any events are being reported for the vehicle and that it appears in its current location on the map.
       
    2. Go to the Admin >> Devices screen.
       
    3. Perform a search using the serial number of the LMU. (See Searching for Devices for details if needed.)
       
    4. Check the Last Event Time column to make sure that it shows a recent timestamp.
        
      If the event timestamp is recent, the unit is connecting to cellular and is reporting data as expected.
       
    5. Check the Asset Name column as well to make sure that an asset is assigned to the device. (This is required in order for the location to be displayed on the CalAmp map for devices that aren't cargo monitoring.)
        
      If no asset name appears in the Asset Name column, add an asset as shown in Adding an Asset.
       
  8. If step 7 shows that the unit still isn't reporting data to CalAmp, try swapping out the nonfunctioning LMU for a known working LMU, just to check for certain whether the device is the problem.


If you've tried all these troubleshooting steps and the device is still malfunctioning, you can open a ticket at CalAmp Support Page, as shown in Returning Hardware and Obtaining a Replacement [Performing an RMA].