Camshaft Position Sensor - Miata
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.
NOTE:
May require removal of PCM to gain access to wire terminals.
- Remove and inspect Camshaft Position (CMP) sensor 3-pin harness connector. Clean off any metal particles or shavings. Reinstall CMP sensor. See CAMSHAFT POSITION SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION article.
- Connect scan tool to DLC-2. Start engine. Using scan tool, enter vehicle information. Connect oscilloscope positive test lead to PCM 24-pin harness connector terminal No. 3V (Gray/Blue wire) and negative test lead to 31-pin harness connector terminal No. 4AF (White/Red wire). See Fig 1. Select DIGITAL MEASUREMENT SYSTEM, then FREQUENCY METER. Press link key to select RPM PID. Select PID/DATA MONITOR, then PCM. Press START.
- Set oscilloscope to 2.0V/DIV (Y), 20ms/DIV (X), DC range. Inspect wave profile with engine idling. See Fig 2. If wave profile or voltage readings are not as specified, check following harnesses:
- Check for open or short in CMP signal circuit between CMP sensor 3-pin harness connector terminal "B" and PCM 24-pin harness connector terminal No. 3V (Gray/Blue wire).
- Check for open or short in power circuit between CMP sensor 3-pin harness connector terminal "A" and main relay 4-pin harness connector terminal "D" through common connector (White/Red wire).
- Check for open in ground circuit (Black/Blue wire) between CMP sensor 3-pin harness connector terminal "C" and PCM 31-pin harness connector terminal No. 4A.
Repair or replace as necessary. Reconnect CMP sensor. Check protrusion on intake camshaft for damage and cracks. Repair as necessary.
Courtesy of MAZDA MOTORS CORP.