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.
1998 Mazda 626 DX, StandardFACTORY OEM SERVICE PROCEDURE
Engine Controls - System/Component Tests
- Introduction
- Air Induction Systems
- Computerized Engine Controls
- Engine Sensors & Switches
- BRAKELIGHT Switch
- Camshaft Position (CMP) Sensor
- Closed Throttle Position Switch
- Clutch Switch (M/T)
- Crankshaft Position (CKP) Sensor
- EGR Boost Sensor
- Engine Coolant Temperature (ECT) Sensor
- Fuel Tank Pressure Sensor
- Heated Oxygen Sensor (Ho2S)
- Intake Air Temperature (IAT) Sensor
- Knock Sensor
- Manifold Absolute Pressure (Map) Sensor
- Mass Airflow (MAF) Sensor
- Neutral Switch (M/T)
- Power Steering Pressure (PSP) Switch
- Throttle Position Sensor
- Transmission Range Sensor
- Transmission Range Switch (A/T)
- Vehicle Speed Sensor (VSS)
- Relays & Solenoids
- Fuel Pump Relay
- Fuel Pump Resistor & Relay (Speed)
- Main Relay
- Solenoids
- Air By-Pass Valve (ABV) Vacuum Solenoid Valve (Millenia 2.3L)
- Air By-Pass Valve (ABV) Vent Solenoid Valve (Millenia 2.3L)
- By-Pass Air Solenoid Valve (Millenia 2.3L)
- By-Pass Air Solenoid Valve (MPV)
- Charge Air Cooler By-Pass Solenoid Valve (Millenia 2.3L)
- EGR Vacuum Solenoid Valve
- EGR Vent Solenoid Valve
- Manifold Absolute Pressure (MAP) Sensor Solenoid Valve (Millenia 2.3L)
- Pressure Regulator Control (PRC) Solenoid Valve (Except MPV)
- Pressure Regulator Control (PRC) Solenoid Valve (MPV)
- Purge Control Solenoid
- VICS Solenoid
- VRIS Solenoid
- Fuel System
- Idle Control System
- Ignition System
- Emission Systems & Sub-Systems
- Exhaust Gas RECIRCULATION (EGR) System
- Fuel Evaporation
- System Inspection
- Charcoal Canister (MPV & 626)
- Charcoal Canister (Millenia & Protege)
- Canister Drain Cut Valve
- One-Way Check Valve (Millenia)
- 2-Way Check Valve (MPV & Protege)
- Cut Valve (MPV)
- Tank Pressure Control Valve (MPV & Protege)
- Fuel Vapor Rollover Valve (Protege & 626)
- Fuel Vapor Rollover Valve (Millenia)
- Purge Control Solenoid Valve
- Separator (MPV)
- Positive Crankcase Ventilation (PCV)
- Vacuum Pump
Factory Service Tools
Use the Manual With the Right Hardware
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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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