626 2.0L (Using Breakout Box)
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 Mazda Protege5, 2002 Mazda Protege, 2002 Mazda Millenia, 2002 Mazda MX-5 Miata, and 2002 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.
- Warm engine to normal operating temperature. Turn ignition switch off. Connect 104-Pin Breakout Box (49-UN01-130) between PCM and PCM harness connector. See Figure .
- Voltage Inspection
Turn ignition switch on. Measure voltage at PCM terminal No. 60 (front HO2S) or No. 35 (rear HO2S). See HO2S VOLTAGE (626 2.0L) table. If voltage is not as specified, check wiring harness and connectors between PCM and HO2S. See WIRING DIAGRAMS article. Also check intake-air system, fuel system and self-diagnostic system. Repair as necessary. If system or wiring harness problems are not present, replace HO2S. - HO2S Heater Resistance Inspection
Disconnect HO2S 4-pin connector. Using ohmmeter, measure resistance between HO2S 4-pin connector terminals "C" and "D". See Fig 1 . Resistance should be about 6 ohms. If resistance is not as specified, replace HO2S.
HO2S VOLTAGE (626 2.0L)
| Application | Volts | ||
|---|---|---|---|
| Rear HO2S | |||
| Acceleration | About 0 | ||
| Deceleration | About 0 | ||
| Idle | About 0 | ||
| Front HO2S | |||
| Ignition On | Less Than 1.0 | ||
| Acceleration | 0.5-1.0 | ||
| Deceleration | 0-0.5 | ||
| Idle | |||
| After Warm Up | 0.1-0.9 | ||
| Engine Cold | Less Than 0.5 | ||