Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1987 Mazda 626 BaseFACTORY OEM SERVICE PROCEDURE
Control Unit Testing: 323
CONTROL UNIT TESTING (323)(1)
| Terminal | Connection | Voltage (When Operating Properly) | ||
|---|---|---|---|---|
| A & D | Control System Tester | 12-13V | ||
| E | Throttle Position Sensor "IDL" Terminal | Zero (12-13V With Accelerator Pedal Depressed | ||
| G | Clutch & Neutral Switch | Zero (In Neutral) 12-13V (In Gear, Pedal Released | ||
| H | Coolant Temperature Switch | Zero (12-13V Below 63°F-17°C) | ||
| I | Throttle Position Sensor "POW" Terminal | 12-13V (Zero With Accelerator Pedal Depressed | ||
| M | Ignition Negative Terminal | 12-13V | ||
| S | A/C Cutout Relay | 12-13V | ||
| U | Ignitor (Black Connector) | 12-13V | ||
| V | Idle-Up Solenoid E/L | 12-13V | ||
| W | Control System Tester | 12-13V | ||
| 2A | Atmospheric Pressure Sensor | About V | ||
| 2B | Airflow Meter "Vc" Terminal | About 8V | ||
| 2C | Ground | Zero | ||
| 2D | Oxygen Sensor | Zero | ||
| 2E | Airflow Meter "Vs" Terminal | About 1.8V | ||
| 2H | Atmospheric Pressure Sensor | About 4V | ||
| 2I | Coolant Thermosensor | About .5V (Engine at Normal Operating Temperature) | ||
| 2J | Airflow Meter "THA" Terminal | About 1.6V | ||
| 2K | Evaporation Solenoid (No. 2) | 12-13V | ||
| 2P | Evaporation Solenoid | 12-13V | ||
| 2R | Ground | Zero | ||
| 3A | Ground | Zero | ||
| 3B | Starter "ST" Terminal | Zero (About 10V When Cranking Engine) | ||
| 3C & 3E | Injectors | 12-13V (3C Injectors 3 & 4, 3E Injectors 1 & 2) | ||
| 3D | Inhibitor Switch (Auto. Trans.) | Zero (In "P" or "N"), 12-13V (All Others) | ||
| 3G | Ground | Zero | ||
| 3I | Airflow Meter "Vb" Terminal | 12-13V | ||
| 3J | Battery | 12-13V | ||
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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:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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