EGR Boost Sensor - Except MAZDA6 (3.0L) & 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.
- Voltage Inspection
Disconnect PCM 104-pin harness connector and install 104-Pin Breakout Box (49-UN01-130) to PCM and PCM harness connector. See Figure. Turn ignition on. Disconnect vacuum hose from between EGR boost sensor and EGR boost sensor solenoid valve. Connect vacuum pump to EGR boost sensor port. Ensure breakout box terminal No. 34 voltage reading is 2.3-4.7 volts. Apply 7.85 in. Hg to EGR boost sensor and verify breakout box terminal No. 34 voltage drops to 0.8-1.3 volts. If EGR boost sensor voltage reading is not as specified, check for open or short circuit. Go to next step. - Open Circuit Inspection
Check for continuity in following circuits:- EGR boost (Barometric pressure) signal circuit between EGR boost sensor 3-pin harness connector terminal "A" and breakout box terminal No. 34. See Fig 1.
- Constant voltage circuit between EGR boost sensor 3-pin harness connector terminal "C" and breakout box terminal No. 90.
- GND circuit between EGR boost sensor 3-pin harness connector terminal "B" and breakout box terminal No. 91.
If continuity is not present, repair open circuit in suspect wire or replace wire harness. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. If open circuit is not present, replace CKP sensor.
- Short Circuit Inspection
Check for continuity between following terminals:- EGR boost (Barometric pressure) signal circuit between EGR boost sensor 3-pin harness connector terminal "A" and breakout box terminal No. 34.
- Constant voltage circuit between EGR boost sensor 3-pin harness connector terminal "C" and breakout box terminal No. 90.
If continuity is present, repair short circuit in suspect wire or replace wire harness.