EGR Boost Sensor (Miata)
- Inspect EGR boost sensor for damage or cracks. Inspect vacuum hose for improper routing, kinks or leaks. If no problems are found with vacuum hose or EGR boost sensor, go to next step. If any problems are found, repair as necessary.
- Open Circuit Inspection
Check for continuity in following circuits:- EGR boost circuit between EGR boost sensor 3-pin harness connector terminal "B" (Blue/Yellow wire) and PCM 31-pin harness connector terminal No. 4AE. See Figure.
- Reference voltage circuit between EGR boost sensor 3-pin harness connector terminal "C" and PCM 31-pin harness connector terminal No. 4L.
- GND circuit between EGR boost sensor 3-pin harness connector terminal "A" and PCM 31-pin harness connector terminal No. 4O through common connector.
If continuity is present, go to next step. 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.
- Short Circuit Inspection
Check for continuity between following:- EGR boost sensor 3-pin harness connector terminal "C" and PCM 31-pin harness connector terminal No. 4L through common connector to GND.
- EGR boost sensor connector 3-pin harness connector terminal "B" and PCM 31-pin harness connector terminal No. 4AE through common connector to GND.
If continuity is present, repair open circuit in suspect wire or replace wire harness.