An atmospheric pressure sensor is used to detect changes in barometric pressure that can alter the intake air density, resulting in improper air-fuel ratio.

To compensate for this type of deviation, the amount of fuel injected is controlled.

For example, the amount of fuel injected is decreased to compensate for the lower intake air density caused by the decreased barometric pressure.(high altitude) The atmospheric pressure sensor is located in the ECM.

If the signal below threshold value, the ECM judges this as a fault and DTC is set.

Fig 1) Normal value with barometric pressure sensor sensor at idle speed

Is the Current data displayed correctly ?

▶ Fault is intermittent caused by poor contact in the sensor’s and/or ECM’s connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

▶ Substitute with a known-good ECM and check for proper operation.

If the problem is corrected, replace ECM and then go to "Verification of Vehicle Repair" procedure.

After a repair, it is essential to verify that the fault has been corrected.

3.

Are any DTCs present ?

Go to the applicable troubleshooting procedure.

System is performing to specification at this time.