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.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSMAZDA1999626 ES, 2.5 D, STANDARDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 335 (SYMPTOM TROUBLESHOOTING (ENGINE CONTROL SYSTEM AJ))
1999 Mazda 626 ES, 2.5 D, Standard
Section 335 (Symptom Troubleshooting (Engine Control System AJ))
1999 Mazda 626 ES, 2.5 D, StandardSECTION Section 335 (Symptom Troubleshooting (Engine Control System AJ))
WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
- Control System Device And Control Relationship Chart
- Foreword
- Intermittent Concern Troubleshooting
- Symptom Diagnostic Index
- Symptom Quick Diagnostic Chart
- No. 1 Melting Of Main Or Other Fuses
- No. 2 Mil Illuminates
- No. 3 Will Not Crank
- No. 4 Hard Start/Long Crank/Erratic Start/Erratic Crank
- No. 5 Engine Stalls -- After Start/At Idle
- No. 6 Cranks Normally But Will Not Start
- No. 7 Slow Return To Idle
- No. 8 Engine Runs Rough/Rolling Idle
- No. 9 Fast Idle/Runs On
- No. 10 Low Idle/Stalls During Deceleration
- No. 11 Engine Stalls/Quits, Engine Runs Rough, Misses, Buck/Jerk, Hesitation/Stumble, Surges
- No. 12 Lack/Loss Of Power -- Acceleration/Cruise
- No. 13 Knocking/Pinging -- Acceleration/Cruise
- No. 14 Poor Fuel Economy
- No. 15 Emission Compliance
- No. 16 High Oil Consumption/Leakage
- No. 17 Cooling System Concerns-Overheating
- No. 18 Cooling System Concerns -- Runs Cold
- No. 19 Exhaust Smoke
- No. 20 Fuel Odor (In Engine Compartment)
- No. 21 Engine Noise
- No. 22 Vibration Concerns (Engine)
- No. 23 A/C Does Not Work Sufficiently
- No. 24 A/C Always On/A/C Compressor Runs Continuously
- No. 25 A/C Does Not Cut Off Under Wide Open Throttle Conditions
- No. 26 Exhaust Sulphur Smell
- No. 27 Fuel Refill Concerns
- No. 28 Fuel Filling Shut Off Issues
- No. 29 Spark Plug Condition
- Engine Control System Operation Inspection
- Input Signal System Investigation Procedure
- Notes
- Finding unusual signals
- Locating the source of unusual signals
- Variable resistance type 1 (APP sensor, TP sensor and EGR boost sensor)
- Investigate the input signal system for variable resistance type 1
- Investigate the standard power supply system for variable resistance type 1
- Investigate the GND system for variable resistance type 1
- Variable resistance type 2 (MAF sensor)
- Investigate the GND system for variable resistance type 2
- Investigate the input signal system for variable resistance type 2
- Investigate the electrical supply system for variable resistance type 2
- Thermistor type (IAT sensor and ECT sensor)
- Investigate the input signal system for thermistor type
- Investigate the GND system for thermistor type
- Main Relay Operation Inspection
- Intake Manifold Vacuum Inspection
- Electronic Throttle Control Inspection
- Fuel Injector Operation Inspection
- Fuel Cut Control System Inspection
- Fuel Pump Operation Inspection
- Fuel Pump Control System Inspection
- Ignition Timing Control Inspection
- Spark Test
- EGR Control System Inspection
- Purge Control System Inspection
- A/C Cut-off Control System Inspection
- Variable Air Duct (VAD) Control System Operation Inspection
- Evaporative Emission (EVAP) System Leak Inspection
- EVAP system leak inspection using WDS or equivalent
- Input Signal System Investigation Procedure
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:
- • 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.