1985 Mazda GLC BaseFACTORY OEM SERVICE PROCEDURE

3-Way Solenoid Valves

  1. Unplug connector from throttle positioner solenoid valve. Valve is located on firewall, behind the carburetor. Apply battery voltage to Yellow/Black terminal, and ground Lt. Green/Red terminal.
  2. Throttle positioner solenoid should be open to manifold vacuum signal. Replace if positioner does not respond correctly.
Fig 1: Adjusting Servo Diaphragm (A/C Models)
G42078
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.