Vacuum Sensor Test

1990 Mazda B2600i LE-5, 2D Pickup, 4WD, AutomaticSECTION Vacuum Sensor Test
  1. Remove vacuum hose and attach hand-held vacuum pump to sensor. Turn ignition on. Check voltage between each terminal and ground while applying 30 in. Hg to sensor. See VACUUM SENSOR TERMINAL VOLTAGEΒ  table. See Figure and Figure .
  2. If voltage at terminals "A", "B", or "C" is not within specification, check wiring harness to sensor. If voltage at terminals "A", "B" or "C" is within specifications, but terminal "D" is not within specifications, replace vacuum sensor.
    VACUUM SENSOR TERMINAL VOLTAGE

    Terminal Voltage
    "A" Less Than 1.5
    "B" 4.5-5.5
    "C" About 12
    "D" 1.4-4.9
RENDER: 1.0x

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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.
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  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
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