626 2.0L (Using Breakout Box)
WARNING: This page is about a different car, the 2001 Mazda Protege, 2001 Mazda Millenia, 2001 Mazda MX-5 Miata, 2001 Mazda MPV, and 2001 Mazda 626. However, it is still accessible from the selected car via links, so may be relevant.
- Warm engine to normal operating temperature. Turn ignition off. Connect 104-Pin Breakout Box (49 UN01 130) to PCM. Measure voltage at PCM terminal No. 60 for front HO2S or No. 35 for rear HO2S. See HO2S VOLTAGE (626 2.0L) table.
- If voltage is not as specified, check wiring harness and connector between PCM and HO2S. Also check intake manifold system, fuel system and self-diagnostic system. Repair as necessary. If no problems are present, replace HO2S.
- To test HO2S heating element, allow HO2S to cool to room temperature. 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 at 68°F (20°C). If resistance is not as specified, replace HO2S.
HO2S VOLTAGE (626 2.0L)
| Application | Volts | |
|---|---|---|
| PCM Terminal No. 35 (Rear HO2S) | ||
| Acceleration | About 0 | |
| Deceleration | About 0 | |
| Idle | About 0 | |
| PCM Terminal No. 60 (Front HO2S) | ||
| Acceleration | 0-1.0 | |
| Deceleration | 0-0.5 | |
| Idle | 0.5-1.0 | |