Fuel Tank Pressure Sensor
WARNING: This page is about a different car, the 1997 Mazda Millenia. However, it is still accessible from the selected car via links, so may be relevant.
- Fuel tank pressure sensor is located on top of fuel tank. Connect Engine Signal Monitor (49 9200 162A) to ECM/PCM, using proper overlay and adapter cables. Turn ignition on. Measure voltage at ECM/PCM terminal 3F.
- With 2 psi (6.7 kPa) of pressure applied to sensor, voltage should be 4-5 volts. With 0 psi (0 kPa) of pressure applied to sensor, voltage should be 2.3-2.8 volts. With 2 in. Hg of vacuum applied to sensor, voltage should be .45-.55 volt. If all voltage readings are as specified, fuel tank pressure sensor is functioning properly. If any voltage reading is not as specified, go to next step.
- Turn ignition off. Check continuity of circuits between fuel tank pressure sensor wiring harness connector and ECM/PCM. See appropriate wiring diagram in WIRING DIAGRAMS - 2.3L article. If continuity exists in all circuits, go to next step. If continuity does not exist in one or more circuits, repair wiring harness as necessary.
- Turn ignition on. Measure voltage at terminal "B" at fuel pressure sensor wiring harness connector. See Fig 1 . Voltage should be less than one volt. Measure voltage at terminal "C" at fuel tank pressure sensor wiring harness connector. Voltage should be 4.5-5.5 volts. If voltage is as specified, replace fuel tank pressure sensor. If voltage is not as specified, locate and repair short circuit in wiring harness. See appropriate wiring diagram in WIRING DIAGRAMS - 2.3L article.