Protege & Protege5

WARNING: This page is about a different car, the 2003 Mazda Protege5, 2003 Mazda Protege, 2003 Mazda MX-5 Miata, 2003 Mazda MPV, and 2003 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

Visually check Mass Airflow (MAF) sensor for cracks or damage. If any damage is present, replace MAF sensor. If MAF sensor is okay but PID values or PCM terminal voltage is out of specification, check for open or short circuit. See MAF SENSOR VOLTAGE SPECIFICATIONS . Go to next step.

Open Circuit Inspection

Disconnect PCM 104-pin harness connector. Connect 104-Pin Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Check for continuity between following terminals:
- MAF signal circuit - MAF sensor 3-pin harness connector terminal "B" (Light Green/Black wire) and breakout box terminal No. 88.
- Power circuit - MAF sensor 3-pin harness connector terminal "C" and main relay 4-pin harness connector terminal "D" (through common connector).
- GND circuit - MAF sensor 3-pin harness connector terminal "A" and breakout box terminal No. 103 through common connector.
If continuity is present, go to next step. If continuity is not present, repair open circuit in appropriate wire or replace wire harness as necessary. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.

Short Circuit Inspection

Check continuity between following terminals:
- MAF signal circuit - MAF sensor 3-pin harness connector terminal "B" and breakout box terminal No. 88 to ground.
- Power circuit - MAF sensor 3-pin harness connector terminal "C" and main relay 4-pin harness connector terminal "D" through common connector to ground.
If continuity is present, repair short circuit to ground in appropriate wire or replace wire harness. If open or short circuit is not present, replace MAF sensor.