Suzuki GA413, Service Manual

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6-88 ENGINE GENERAL INFORMATION AND DIAGNOSIS
GA413
supple
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 POSSIBLE CAUSE
DTC P1450:
D
Barometric pressure sensor voltage is 4.7 V or higher, or
1.6 V or lower
D
ECM (barometric pressure sensor) malfunction
DTC P1451:
D
Vehicle stopped
D
Engine cranking
D
Difference between barometric pressure and intake
manifold absolute pressure is 26 kPa, 200 mmHg or more.
D
Difference between intake manifold absolute pressure at
engine start and pressure after engine start is less than
1.3 kPa, 10 mmHg.
:
2 driving cycle detection logic, monitoring once/1 driving.
D
ECM (barometric pressure sensor) malfunction
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 “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 ACTION YES NO
1 Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE” in this
section.
2 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.
Is it barometric pressure (approx. 100 kPa,
760 mmHg) at sea level?
Substitute a known-
good ECM and recheck. Go to Step 3.