Display showing E4 and unable to communicate, Signal cable routed incorrectly

Potential Symptoms

  • Display(s) showing E4 or has a flashing decimal point and can not communicate to one or more drivers.
  • E4 or blank display with a blinking decimal point on a display further down the signal chain after working on one of the displays.


  • Product Family: Digit and Price Displays
  • Product: Fuelight or DataMaster, Gas Price or Petroleum Price Display, FL or DF digit product, FL-2000, FL-2100, FL-2109, FL-2300, FL-4000, DF-2000, DF-2009, DF-2100, DF-2109, DF-2300, DF-4000
  • Component: Line to Line Signal or Data cable, New install or driver has been replaced or swapped
  • Control System:


  • Signal (data) cable between drivers is routed incorrectly or unplugged.


  • Correct signal cable routing
    1. Route the signal cable (RJ-14 cable) from the output of the host driver to the input of the next client display.
    2. Continue this sequence until all displays are connected.  Note: Do not connect the last display back to the 1st display.
Signal Wiring.png



Close up - Driver.png


KB ID: DD2032623

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