Camshaft Position (CMP) Sensor: Miata
- Remove and inspect camshaft position sensor. Clean off any metal particles or shavings. Reinstall sensor.
- Connect scan tool. Start engine. Using scan tool, enter vehicle info and connect scan tool leads to PCM. See CMP/PCM TERMINAL IDENTIFICATION (MIATA & PROTEGE 1.6L) table. Select DIGITAL MEASUREMENT SYSTEM, then FREQUENCY METER. Press link key to select RPM PID. Select PID/DATA MONITOR, then PCM. Press START.
- Frequency meter should be displayed. Ensure threshold voltage is 2 volts and DC voltage is selected. Frequency should match specifications. See CMP FREQUENCY SPECIFICATIONS (MIATA & PROTEGE 1.6L) table.
- Change scan tool threshold voltage to 6 volts. Ensure frequency is 0 Hz. If frequency is out of specifications, check wiring for open or short circuit. Check camshaft pulley for damage. Repair as necessary.
CMP/PCM TERMINAL IDENTIFICATION (MIATA & PROTEGE 1.6L)
| Test Connection | PCM Terminal | |
|---|---|---|
| Miata | ||
| Positive Lead | 3V | |
| Negative Lead | 4A | |
| Protege 1.6L | ||
| Positive Lead | 85 | |
| Negative Lead | 103 | |
CMP FREQUENCY SPECIFICATIONS (MIATA & PROTEGE 1.6L)
| RPM | Frequency - (Hz) |
|---|---|
| 650-750 (Protege 1.6L Idle) | 16-18 |
| 750-850 (Miata Idle) | 18-22 |
| 1000 | 25 |
| 2000 | 50 |
| 3000 | 75 |