Suzuki 2000 Grand Vitara SQ625 Service Manual page 85

TROUBLESHOOTING (DTC P0400)
STEP
1 Was "ENGINE DIAG. FLOW TABLE" performed?
2 Is there DTC P0403 (EGR circuit malfunction)?
3 Do you have SUZUKI scan tool?
4 EGR Valve Operation Check:
1) With ignition switch OFF, install SUZUKI scan tool.
2) Check EGR system referring to Section 6E1.
Is it in good condition?
5 MAP Sensor Check:
1) Check MAP sensor for performance referring to
Section 6E1.
Is check result satisfactory?
6 EGR Valve Power Supply Circuit Check:
1) With ignition switch OFF, disconnect EGR valve
coupler.
2) With ignition switch ON, check voltage between
C04-2 and ground, C04-5 and ground.
Is each voltage 10 – 14 V?
7 EGR Valve Stepper Motor Coil Circuit Check:
1) With ignition switch OFF, connect EGR valve coupler
and disconnect ECM (PCM) couplers.
2) Check resistance between C51-3-4 and C51-2-13,
C51-2-14, C51-2-15, C51-2-16.
Is each resistance 20 – 24 W at 20_C, 68_F?
8 MAP Sensor Check:
1) Check MAP sensor for performance referring to
Section 6E1.
Is check result satisfactory?
ACTION
ENGINE DIAGNOSIS (G16 / J20 ENGINES) 6-81
YES
Go to Step 2.
Go to DTC P0403
Diag. Flow Table.
Go to Step 4.
Go to Step 5.
Intermittent trouble
or faulty ECM
(PCM). Check for
intermittent refer-
ring to "Intermittent
and Poor Connec-
tion" in Section 0A.
Go to Step 7.
Go to Step 8.
EGR passage
clogged or EGR
valve malfunction.
If all above are OK,
intermittent trouble
or faulty ECM
(PCM).
Check for intermit-
tent referring to
"Intermittent and
Poor Connection" in
Section 0A.
NO
Go to "ENGINE
DIAG. FLOW
TABLE".
Go to Step 3.
Go to Step 6.
Go to Step 6.
Repair or replace.
Faulty "Bl/B" wire.
Faulty "Lg", "Lg/W",
"Lg/R", "Lg/Y" wire
or EGR valve.
Repair or replace.