1A
DTC P0401 / P0402: Exhaust Gas Recirculation Flow Insufficient Detected / Excessive Detected
System and Wiring Diagram
1. EGR valve 4. Sensed information 7. “IG” fuse 10. Main relay
2. Intake manifold 5. Fresh air 8. Relay box 11. “FI” fuse
3. ECM 6. Exhaust gas 9. Ignition switch 12. “IGN1” fuse
DTC Detecting Condition and Trouble Area
DTC detecting condition Trouble area
DTC P0401:
Difference in intake manifold absolute pressure between opened EGR valve and closed EGR valve is smaller than specified value.
(*2 driving cycle detection logic, monitoring once/1 driving)
DTC P0402:
Difference in intake manifold absolute pressure between opened EGR valve and closed EGR valve is larger than specified value.
(*2 driving cycle detection logic, monitoring once/1 driving)
• EGR valve
• EGR passage
• MAP sensor
• ECM
DTC Confirmation Procedure
WARNING:
• When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
• Road test should be carried out with 2 persons, a driver and a tester, on a level road.
NOTE:
Check to make sure that the following conditions are satisfied when using this “DTC confirmation procedure”.
• Intake air temperature at engine start: –10 °C (14 °F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Engine coolant temperature: 70 °C (158 °F) to 150 °C (302 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Run engine at idle for 10 min.
5) Drive vehicle and increase engine speed 3000 rpm in 3rd gear.
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting for 5 sec. or more. (Keep fuel cut condition for 5 sec. or more) If fuel cut condition is not kept for 5 sec. or more, coast down a slope in engine speed 1000 – 3000 rpm for 5 sec. or more.
7) Stop vehicle and run engine at idle.
8) Check DTC and pending DTC by using scan tool.
DTC Troubleshooting
Step Action YES NO
1
Was “Engine and Emission Control System Check” performed?
Go to Step 2.
Go to Engine and Emission Control System Check:M13A with VVT .
2
Do you have SUZUKI scan tool?
Go to Step 3.
Go to Step 5.
3
EGR valve operation check
1) With ignition switch turned OFF, install SUZUKI scan tool to DTC.
2) Check EGR system referring to EGR Valve Inspection:M13A .
Is it in good condition?
Go to Step 4.
Go to Step 5.
4
MAP sensor check
1) Check MAP sensor for performance referring to Manifold Absolute Pressure (MAP) Sensor Inspection:M13A .
Is check result satisfactory?
Intermittent trouble or faulty ECM. Check for intermittent referring to Intermittent and Poor Connection Inspection .
Repair or replace.
5
EGR valve control circuit check
1) Check that EGR valve control circuits are in good condition referring to Step 2 to 5 of DTC P0403: Exhaust Gas Recirculation Control Circuit:K9K .
Are circuits in good condition?
Go to Step 6.
Repair or replace EGR valve control circuit(s).
6
EGR valve check
1) Check EGR valve referring to EGR Valve Inspection:M13A .
Is check result satisfactory?
Go to Step 7.
Faulty EGR valve.
7
MAP sensor check
1) Check MAP sensor for performance referring to Manifold Absolute Pressure (MAP) Sensor Inspection:M13A .
Is check result satisfactory?
EGR passage clogged. If OK, substitute a known-good ECM and recheck.
Repair or replace.
NOTE:
Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.