Suzuki GA413 Service Manual page 853

DTC P0400
INSPECTION
STEP
1 Was "ENGINE DIAG. FLOW TABLE" performed?
2 EGR Valve Operation Check:
1) With ignition switch OFF, install SUZUKI scan
tool.
2) Check EGR system referring to Section 6E.
Is it in good condition?
3 MAP Sensor Check:
1) Check MAP sensor for performance referring to
Section 6E.
Is check result satisfactory?
4 EGR Valve Power Supply Circuit Check:
1) With ignition switch OFF, disconnect EGR valve
coupler.
2) With ignition switch ON, check voltage between
"a" and ground, "b" and ground.
Is each voltage 10 – 14 V?
5 EGR Valve Stepper Motor Coil Circuit Check:
1) With ignition switch OFF, connect EGR valve
coupler and disconnect ECM couplers.
2) Check resistance between L20-2 and C23-18,
C23-19, C23-27, C23-28.
Is each resistance 20 – 24 W at 205C, 685F?
6 MAP Sensor Check:
1) Check MAP sensor for performance referring to
MAP SENSOR INDIVIDUAL CHECK in Diag.
FLOW TABLE P0105.
Is check result satisfactory?
Fig. 1 for Step 5
1. EGR valve connector
ACTION
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-77
YES
Go to Step 2.
Go to Step 3.
Intermittent trouble or
faulty ECM.
Check for intermittent
referring to "Intermittent
and Poor Connection" in
Section 0A.
Go to Step 5.
Go to Step 6.
EGR passage clogged
or EGR valve malfunc-
tion.
If all above are OK, in-
termittent trouble or
faulty ECM.
Check for intermittent
referring to "Intermittent
and Poor Connection" in
Section 0A.
NO
Go to "ENGINE DIAG.
FLOW TABLE".
Go to Step 4.
Repair or replace.
Faulty "BLK/RED" wire.
Faulty "RED/BLK"
"RED", "RED/YEL",
"RED/BLU" wire or EGR
valve.
Repair or replace.