Feedback Carburetor (B2200) Control Unit

1991 Mazda 929 BaseSECTION Feedback Carburetor (B2200) Control Unit

The Electronic Control Unit (ECU), through various input sensors, monitors battery voltage, engine RPM, amount of intake air, cranking signal, intake temperature, radiator and engine coolant temperatures, oxygen concentration in exhaust gases, EGR operation, throttle opening, atmospheric pressure, gearshift lever position, clutch engagement, and A/C compressor operation.

The ECU uses all input information to control air/fuel solenoid valve, idle-up solenoid valves, slow fuel-cut solenoid valve, coasting richer solenoid valve, vacuum solenoid valve, Air Control Valve (ACV) solenoid valve, purge solenoid valve, and duty solenoid valve. ECU has a built-in, fail-safe mechanism. If a fault occurs while driving, ECU will substitute pre-programmed values. Driving performance will be affected, but vehicle may still be driven.

RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

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.