Suzuki WagonR+ RB310 Service Manual page 2442

DTC P0400
INSPECTION
STEP
1 Was "ENGINE DIAG. FLOW TABLE" performed?
2 1) Turn ignition switch ON.
2) Does EGR stepper motor operation for 0.6
second after ignition switch OFF?
3 With ignition switch at OFF, check voltage between
E22-2, 8, 9, 17 terminals of ECM and body ground.
Is voltage about 0 V? See Fig. 2.
Next turn ignition switch to ON, check voltage
between E22-2, 8, 9, 17 terminals of ECM and
body ground.
Is voltage within 10 – 14 V?
4 Do you have SUZUKI scan tool?
5 Check EGR system referring to "EGR SYSTEM
-system inspection" in Section 6E.
Is check result satisfactory?
6 1) Disconnect EGR valve coupler with ignition
switch OFF.
2) Check voltage between "B/R" wire terminals
of EGR valve coupler and body ground with
ignition switch ON. See Fig. 1.
3) Are they about 10 – 14 V?
7 Check EGR valve referring to "EGR SYSTEM
-Inspection" in Section 6E.
Is it good condition?
Fig. 1 for step 6
1. EGR valve coupler
ACTION
Fig. 2 for step 3
YES
Go to Step 2.
Go to Step 3.
Go to Step 4.
Go to Step 5.
Substitute a known-
good ECM and recheck.
Go to Step 3.
EGR valve harness
("G /Y", "G/B", "G/R" or
"G/Or" wire) open or
short or poor coupler
connection (D09-2,
E22-2, 8, 9, 17) If wire
harness and connection
are OK, substitute a
known-good ECM and
recheck.
ENGINE DIAGNOSIS 6-83
NO
Go to "ENGINE DIAG.
FLOW TABLE".
Go to Step 6.
Go to Step 7.
Stuck or faulty
EGR valve or clogged
EGR gas passage.
If all above are OK,
substitute a known-
good ECM and recheck.
Stuck or faulty
EGR valve or clogged
EGR gas passage.
"B/R" wire open or
short
Faulty EGR valve