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 432 (ON-BOARD DIAGNOSTIC (ENGINE CONTROL SYSTEM 13BMSP])DTC P0102DIAGNOSTIC PROCEDURE

1999 Mazda 626 ES, 2.5 D, Standard

Diagnostic procedure

1999 Mazda 626 ES, 2.5 D, StandardSECTION Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0102 DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Verify related Service Bulletins and/or on-line repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	INSPECT MAF/IAT SENSOR CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the MAF/IAT sensor connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 9.
3		No	Go to the next step.
4	INSPECT MAF SENSOR POWER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GROUND Turn the ignition switch to the ON position (Engine off). Measure the voltage between MAF/IAT sensor terminal A (wiring harness-side) and body ground. Is the voltage B+ ?	Yes	Go to the next step.
4		No	Repair or replace the wiring harness for a possible open circuit or short to ground, then go to Step 9.
5	INSPECT MAF SENSOR SIGNAL CIRCUIT FOR SHORT TO GROUND Turn the ignition switch off. Inspect for continuity between MAF/IAT sensor terminal C (wiring harness-side) and body ground. Is there any continuity?	Yes	Repair or replace the wiring harness for a possible short to ground, then go to Step 9.
5		No	Go to the next step.
6	INSPECT MAF SENSOR Inspect the MAF sensor. (See MASS AIR FLOW (MAF) SENSOR INSPECTION .) Is there any malfunction?	Yes	Replace the MAF/IAT sensor, then go to Step 9. (See MASS AIR FLOW (MAF)/INTAKE AIR TEMPERATURE (IAT) SENSOR REMOVAL/INSTALLATION .)
6		No	Go to the next step.
7	INSPECT PCM CONNECTOR FOR POOR CONNECTION Turn the ignition switch off. Disconnect the PCM connector. Inspect for poor connection (such as damaged/pulled-out pins, corrosion). Is there any malfunction?	Yes	Repair or replace the terminal, then go to Step 9.
7		No	Go to the next step.
8	INSPECT MAF SENSOR SIGNAL CIRCUIT FOR OPEN CIRCUIT Turn the ignition switch off. Inspect for continuity between MAF/IAT sensor terminal C (wiring harness-side) and PCM terminal 5N (wiring harness-side). Is there continuity?	Yes	Go to the next step.
8		No	Repair or replace the wiring harness for a possible open circuit, then go to the next step.
9	VERIFY TROUBLESHOOTING OF DTC P0102 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the WDS or equivalent. Start the engine. Is the same DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION .)
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE .) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE .)
10		No	DTC troubleshooting completed.

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.

Shop Manual-Ready Tools Free Quote Check Quote Shield Pro

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.