Dtc P1450 Barometric Pressure Sensor Circuit Malfunction Dtc P1451 Barometric Pressure Sensor Performance Problem - Suzuki Engine 2002 GRAND VITARA SQ420 Service Manual

6-1-132 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H25 ENGINE)
DTC P1450 Barometric Pressure Sensor Circuit Malfunction
DTC P1451 Barometric Pressure Sensor Performance Problem
SYSTEM DESCRIPTION
Barometric pressure sensor is installed in ECM (PCM).
DTC DETECTING CONDITION AND TROUBLE AREA
DTC DETECTING CONDITION
P1450
Barometric pressure sensor voltage is less than 0.1 V or
more than 5.1 V.
P1451
Barometric pressure value does not agree with calculated
barometric pressure.
DTC CONFIRMATION PROCEDURE
NOTE:
Check to make sure that following conditions are satisfied when using this DTC CONFIRMATION PRO-
CEDURE.
• Intake air temperature : between 5°C and 70°C (6.8°F and 158°F)
• Atmospheric pressure : higher than 560 mmHg (Altitude : lower than 2790 m (9150 ft))
1) With ignition switch OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC by using scan tool if any.
3) Start engine and warm up to normal operating temperature.
4) Run engine at idle speed for 30 sec.
5) Check DTC and pending DTC by using scan tool.
DTC TROUBLESHOOTING
Step
1 Was "Engine Diag. Flow Table" performed?
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 seal level?
3 Check MAP Sensor
1) Remove MAP sensor from intake manifold
and connect vacuum pump gauge to MAP
sensor.
2) Connect scan tool to DLC and turn ignition
switch ON.
3) Check intake manifold absolute pressure
displayed on scan tool under following con-
ditions.
Is check result satisfactory?
Action
TROUBLE AREA
Barometric pressure sensor in ECM (PCM).
MAP sensor
Yes
Go to Step 2.
Substitute a known-good
ECM (PCM) and recheck.
Check air intake system
for air being drawn in and
engine compression.
If OK, then substitute a
known-good ECM and
recheck.
No
Go to "Engine Diag. FLow
Table".
Go to Step 2.
Replace MAP sensor.