FixVault

Economy Control

  1. Check voltage on 2-pin plug next to DME control unit. Plug on left is for economy control and upshift indicator (square version). Plug on right is for altitude correction control unit (round version).
  2. Terminal No. 1 (Black wire) should have battery voltage with ignition turned on. Terminal No. 2 of 2-pin plug provides injection signal with engine running. Signal may be checked with an oscilloscope. Injection signal increases in width with engine speed. See Fig 1 .
  3. Tachometer must be removed (plugs remain connected) to measure Hall sensor signals in speedometer. Terminals No. 5 and "H+" should have battery voltage with ignition turned on.
  4. Connect voltmeter on terminal "HG" (Hall sensor pulse). Lift and turn left rear wheel slowly by hand. With each wheel revolution, voltage should increase and decrease 4 times. Voltage should range from less than one volt to more than 6 volts (square wave pulses).
Fig 1: Economy Control & Upshift Indicator Connectors
G68150