6-1-94 ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13)
Fig. 1 for Step 1
When using SUZUKI scan tool:
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 (PCM).
DTC DETECTING CONDITION
POSSIBLE CAUSE
DTC P1450:
Barometric pressure: 136 kPa 1025 mmHg or higher, or
33 kPa 250 mmHg or lowerECM (PCM) (barometric pressure sensor)
malfunction
DTC P1451:
Vehicle stopped
Engine cranking
Difference between barometric pressure and intake
manifold absolute pressure is 26 kPa, 200 mmHg or more
2 driving cycle detection logic, monitoring once / 1 driving.Manifold absolute pressure sensor and its
circuit malfunction
ECM (PCM) (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 “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
INSPECTION
DTC P1450:
Substitute a known-good ECM (PCM) 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
ACTIONYESNO
11) 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?Substitute a known-
good ECM (PCM) and
recheck.Go to Step 2.
1. Ignition switch
2. Main relay
3. Ignition coil assembly
for No.1 and No.4
spark plugs
4. Ignition coil assembly
for No.2 and No.3
spark plugs5. CMP sensor
6. CKP sensor
7. No.1 spark plug
8. No.2 spark plug
9. No.3 spark plug
10. No.4 spark plug11. Sensed information
MAP sensor
ECT sensor
IAT sensor
TP sensor
VSSPark / Neutral position signal
(A / T)
Electric load signal
Engine start signal
IGNITION SYSTEM (SFI FOR G13) 6F1-3
SYSTEM WIRING DIAGRAM
DIAGNOSIS
ConditionPossible CauseCorrection
Engine cranks, but will
not start or hard to
startNo spark
Blown fuse for ignition coil
Loose connection or disconnection of lead
wire or high-tension cord(s)
Faulty high-tension cord(s)
Faulty spark plug(s)
Faulty ignition coil
Faulty CKP sensor or crankshaft timing belt
pulley
Faulty ECM (PCM)
Replace.
Connect securely.
Replace.
Adjust, clean or replace.
Replace ignition coil assembly.
Clean, tighten or replace.
Replace.
Poor fuel economy or
engine performanceIncorrect ignition timing
Faulty spark plug(s) or high-tension cord(s)
Faulty ignition coil assembly
Faulty CKP sensor or crankshaft timing belt
pulley
Faulty ECM (PCM)Check related sensors and
crankshaft timing belt pulley.
Adjust, clean or replace.
Replace.
Clean, tighten or replace.
Replace.
