LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2002 >> MPV ES >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Engine Sensors & Switches >> Camshaft Position Sensor >> Miata
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Camshaft Position Sensor: Miata

  1. Remove and inspect Camshaft Position (CMP) Sensor. Clean off any metal particles or shavings. Reinstall sensor.
  2. Remove PCM. Connect oscilloscope test leads to PCM harness connector terminals "3V" (positive) and "4A" (negative). Set oscilloscope settings to 2.0V/DIV (Y), 20ms/DIV (X), DC range.
  3. Connect NGS scan tool to DLC-2. Start engine. Select RPM PID.
  4. Inspect waveform with engine idling. See Fig 1 . If waveform or voltage are not as specified, check for short or open circuit between:
    • CMP sensor 3-pin harness connector terminal "B" and PCM 24-pin harness connector terminal "3V" (Gray/Blue wire).
    • CMP sensor 3-pin harness connector terminal "A" and main relay 4-pin harness connector terminal "D" through common connector (White/Red wire).

    If open or short circuit are found repair or replace wiring harness as necessary. If short or open circuit are not found, replace CMP sensor.

    Fig 1: Identifying CMP Sensor Waveform (Miata 1.8L)
    G00110225Courtesy of MAZDA MOTORS CORP.
scientia non olet · About LEMON Manuals