Dtc P1450 Barometric Pressure Sensor Low/High Input; Dtc P1451 Barometric Pressure Sensor Performance Problem - Suzuki Ignis Service Manual

6-108 ENGINE GENERAL INFORMATION AND DIAGNOSIS

DTC P1450 BAROMETRIC PRESSURE SENSOR LOW/HIGH INPUT

DTC P1451 BAROMETRIC PRESSURE SENSOR PERFORMANCE PROBLEM

WIRING DIAGRAM / CIRCUIT DESCRIPTION
Barometric pressure sensor is installed in ECM.
DTC DETECTING CONDITION
DTC P1450 :
Barometric pressure : Sensor voltage is 4.7 V or higher, or
1.6 V or lower
DTC P1451 :
• Vehicle stopped
• Engine cranking
• Difference between barometric pressure and intake mani-
fold absolute pressure is 26 kPa, 200 mmHg or more
• Difference between intake manifold absolute pressure at
engine start and the pressure after engine start is 1.3 kPa,
10 mmHg or less.
✱2 driving cycle detection logic, monitoring once/1 driving.
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Turn ignition switch ON for 2 sec., crank engine for 2 sec. and run it at idle for 1 min.
4) Check pending DTC in "ON BOARD TEST" or "PENDING DTC" mode and DTC in "DTC" mode.
INSPECTION
DTC P1450 :
Substitute a known-good ECM and recheck.
DTC P1451 :
NOTE:
Note that atmospheric pressure varies depending on weather conditions as well as altitude.
Take that into consideration when performing these check.
Step
1 Check Barometric Pressure Valve.
1) Connect scan tool to DLC with ignition
switch OFF.
2) Turn ignition switch ON and select "DATA
LIST" mode on scan tool.
3) Check manifold absolute pressure. See Fig.
1.
Is it barometric pressure (approx. 100 kPa, 760
mmHg) at sea level?
Action
POSSIBLE CAUSE
• ECM (barometric pressure sensor) malfunc-
tion
• Manifold absolute pressure sensor and its
circuit malfunction
• ECM (barometric pressure sensor) malfunc-
tion
Yes
Substitute a known-good
ECM and recheck.
No
Go to Step 2.