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Home >> Mazda >> 1997 >> MX-5 Miata L4-1.8L DOHC >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> EGR Valve Position Sensor >> Testing and Inspection
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EGR Valve Position Sensor: Testing and Inspection

Using Special Service Tools (Engine signal monitor)

NOTE: The following vacuum values are indicated by relative vacuum from atmospheric pressure.




1. Disconnect the EGR valve position sensor connector.
2. Measure the resistance between terminals A and B by using an ohmmeter.

Specification: 2.7 K ohms @ 20°C (68°F)

3. If not as specified, replace the EGR valve.
4. Connect the EGR valve position sensor connector.




5. Connect the Special Service Tools to the PCM as shown.

CAUTION: Do not apply a vacuum outside of the specified limits. Doing so will damage the EGR valve position sensor.




6. Apply vacuum to the EGR valve position sensor according to the following procedure.




7. Increase the applied vacuum from -101.3 kPa (-29.9 in.Hg) to -117.9 kPa (-34.8 in.Hg) and verify that the PCM terminal 3J voltage decreases accordingly.

NOTE: The output voltage varies with to the measuring condition.

Measuring conditions:
- Input voltage - 5.0 V
- Atmospheric pressure - 101.3 kPa (29.9 in.Hg)
- Outside temperature - 20°C (68°F)

8. If not as specified, perform the following inspection.
A. Harness continuity:
- Between PCM terminal 3O and EGR boost sensor terminal A.
- Between PCM terminal 3I, and EGR boost sensor terminal B.
- Between PCM terminal 3J and EGR boost sensor terminal C.

B. Terminal voltage:
- EGR boost sensor terminal A voltage: Ground (Below 1.0 V)
- EGR boost sensor terminal B voltage: Constant voltage (4.5-5.5 V).

9. If terminal voltage is correct and there is harness continuity, replace the EGR valve position sensor.



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