2000 SUZUKI SWIFT Air

6-94 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0400 EXHAUST GAS RECIRCULATION FLOW MALFUNCTION
WIRING DIAGRAM / CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
Clear DTC with ignition switch ON, check vehicle and environmental condition for :
–Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 122°F or lower
2) Start engine and warm it up to normal operating temperature (70 – 110°C, 158 – 230°F) and run it at idle for
5 min.
3) Increase vehicle speed to 50 – 55 mph, 80 – 88 km/h in 5th gear or in “D” range.
4) Hold throttle valve at that opening position for 2 min. or longer.
5) Increase engine speed to 4000 r/min. in 3rd gear or in “2” range.
6) Release accelerator pedal and with engine brake applied, keep vehicle coasting (fuel cut condition) till
engine speed reaches 1500 r/min.
1. EGR valve [A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
+BECM
C42-18
C42-29
C42-28 C42-17
C42-1
GRY
GRN/ORN
WHT/RED
C42-3 BRN/YEL
BLK/ORN
BLK/ORN BLK/RED1
3
1 2
4
6 5
+BECM
C41-2
C41-9
C41-17 C41-8
C42-1
GRN
GRN/ORN
WHT/RED
C42-3 BRN/YEL
BLK/ORN
BLK/ORN BLK/RED1
3
1 2
4
6 5
[A][B]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
DTC DETECTING CONDITION POSSIBLE CAUSE
While running at specified vehicle speed after engine warm-up
During deceleration (engine speed high with closed throttle position
ON) in which fuel cut is involved, difference in intake manifold abso-
lute pressure between when EGR valve is opened at specified value
and when it is closed is larger or smaller than specified value.
✱2 driving cycle detection logic, monitoring once/1 drivingEGR valve or its circuit
EGR passage
ECM
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent 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.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-95
7) Stop vehicle (don't turn ignition switch OFF) and confirm test results according to following “Test Result Con-
firmation Flow Table”.
TEST RESULT CONFIRMATION FLOW TABLE
INSPECTION
Step Action Yes No
1Check DTC in “DTC” mode and pending DTC in
“ON BOARD TEST”.
Is DTC or pending DTC displayed?Proceed to applicable
DTC flow table.Go to Step 2.
2 Set scan tool to “READINESS TESTS” mode
and check if testing has been completed.
Is test completed?No DTC is detected.
(Confirmation test is com-
pleted)Repeat DTC confirmation
procedure.
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Do you have SUZUKI scan tool? Go to Step 4. Go to Step 5.
3 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?Go to Step 4. Go to Step 5.
4 MAP Sensor Check :
1) Check MAP sensor for performance refer-
ring to Section 6E1.
Is check result satisfactory?Intermittent trouble or
faulty ECM. Check for
intermittent referring to
“Intermittent and Poor
Connection” in Section
0A.Repair or replace.

6-96 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Fig. 1 for Step 55 EGR Valve Power Supply Circuit Check :
1) With ignition switch OFF, disconnect EGR
valve coupler.
2) With ignition switch ON, check voltage
between terminal 2 and ground terminal 5 of
EGR valve connector and ground.
Is each voltage 10 – 14 V?Go to Step 7. Faulty “BLK/RED” wire.
6 EGR Valve Stepper Motor Coil Circuit Check :
1) With ignition switch OFF, connect EGR
valve coupler and disconnect ECM cou-
plers.
2) Check resistance between C41-5 and C41-
2, 9, 8, 17 (Case of TYPE A. See NOTE) or
C42-17, 18, 28, 29 (Case of TYPE B. See
NOTE).
Is each resistance 20 – 24 Ω at 20°C, 68°F?Go to Step 8. Faulty “GRN” (Case of
TYPE A. See NOTE) or
“GRY” (Case of TYPE B.
See NOTE), “GRN/ORN”,
“WHT/RED”, “BRN/YEL”
wire or EGR valve.
7 MAP sensor Check :
1) Check MAP sensor for performance refer-
ring to Section 6E1.
Is check result satisfactory?EGR passage clogged or
EGR valve malfunction. If
all above are OK, intermit-
tent trouble or faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Repair or replace. Step Action Yes No
1. EGR valve connector

6-98 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
Clear DTC with ignition switch ON, check vehicle and environmental condition for :
–Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp. : –10°C, 14°F or higher
–Intake air temp. : 70°C, 158°F or lower
–Engine coolant temp. : 70 – 110°C, 158 – 230°F
2) Start engine and drive vehicle at 35 – 45 mph, 55 – 65 km/h for 8 min. or longer.
While this driving, if “Catalyst Monitoring TEST COMPLETED” is displayed in “READINESS TESTS” mode
and DTC is not displayed in “DTC” mode, confirmation test is completed.
If “TEST NOT COMPLETE” is still being displayed, continue test driving.
3) Decrease vehicle speed at 30 – 40 mph, 50 – 60 km/h, and hold throttle valve at that opening position for 2
min. and confirm that short term fuel trim vary within – 20% – +20% range.
4) Stop vehicle (do not turn ignition switch OFF) and confirm test results according to following “Test Result
Confirmation Flow Table”.
TEST RESULT CONFIRMATION FLOW TABLE
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and tester, on a level road.
Step Action Yes No
1 Check DTC in “DTC” mode and pending DTC in
“ON BOARD TEST” or “PENDING DTC” mode.
Is DTC or pending DTC displayed?Proceed to applicable
DTC Diag. Flow Table.Go to Step 2.
2 Set scan tool to “READINESS TESTS” mode
and check if testing has been completed.
Is test completed?No DTC is detected (con-
firmation test is com-
pleted).Repeat DTC confirmation
procedure.

6-106 ENGINE GENERAL INFORMATION AND DIAGNOSIS
INSPECTION
Fig. 1 for Step 3Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Is SUZUKI scan tool available? Go to Step 3. Go to Step 4.
3 Check Idle Air Control System.
1) Connect SUZUKI scan tool to DLC with igni-
tion switch OFF, set parking brake and
block drive wheels.
2) Warm up engine to normal operating tem-
perature.
3) Clear DTC and select “MISC TEST” mode
on SUZUKI scan tool. See Fig. 1.
Is it possible to control (increase and reduce)
engine idle speed by using SUZUKI scan tool? Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Go to Step 5.
4 Check Idle Air Control System.
1) Remove IAC valve from throttle body refer-
ring to “IAC Valve Removal” in Section 6E1.
2) Check IAC valve for operation referring to
“IAC Valve Inspection” in Section 6E1. See
Fig. 2.
Is check result satisfactory?Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Go to Step 5.
5 Check Wire Harness for open and short.
1) Turn ignition switch OFF.
2) Disconnect IAC valve connector.
3) Check for proper connection to IAC valve at
each terminals.
4) If OK, disconnect ECM connector.
5) Check for proper connection to ECM at
C42-6 terminal.
6) If OK, check “BLK/RED”, “GRN/RED” and
“BLK” circuit for open and short.
Are they in good condition?Replace IAC valve and
recheck.Repair or replace.
[A] : When using SUZUKI scan tool:[ A]

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-109
Table 1
Fig. 1 for Step 1
Fig. 2 for Step 22 Check MAP Sensor.
1) Remove MAP sensor from intake manifold
and connect vacuum pump gauge to MAP
sensor. See Fig. 2.
2) Connect scan tool to DLC and turn ignition
switch ON.
3) Check intake manifold absolute pressure
displayed on scan tool for specified valve.
See Table 1.
Is check result satisfactory?Check air intake system
for air being drawn in and
engine compression.
If OK, then substitute a
known-good ECM and
recheck.Replace MAP sensor. Step Action Yes No
Applying Vacuum Displayed Value on Scan Tool
0 Barometric pressure
(Approx. 100 kPa, 760 mmHg)
27 kPa
200 mmHgBarometric pressure – 27 kPa
(Approx. 73 kPa, 560 mmHg)
67 kPa
500 mmHgBarometric pressure – 67 kPa
(Approx. 33 kPa, 260 mmHg)

6-122 ENGINE GENERAL INFORMATION AND DIAGNOSIS
TABLE B-4 IDLE AIR CONTROL SYSTEM CHECK
INSPECTION
1. IAC valve 2. Main relay 3. To TCM
[A] : Case of TYPE A is shown (See NOTE) [B] : Case of TYPE B is shown (See NOTE)
GRN/RED
BLK/YEL
BRN/WHT
BLK/RED
BLK/RED
ECM
C41-10
C41-6
C41-5
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
3
1
2
C42-6 C41-14 [A]
G02-6 [B]
LT BLU [A]
GRN RED [B]
NOTE:
For TYPE A and TYPE B, refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model.
Step Action Yes No
1 Check engine idle speed and IAC duty referring
to “Idle Speed/IAC Duty Inspection” in Section
6E1.
Is idle speed within specification?Go to Step 2. Go to Step 4.
2 Is IAC duty within specification in Step 1? Go to Step 3. Check for followings :
Vacuum leak
EVAP canister purge con-
trol system
Clog of IAC air passage
Accessory engine load
Closed throttle position
(TP sensor)
Stuck of PCV valve
3 Is engine idle speed kept specified speed even
with headlight ON?System is in good condi-
tion.Check IAC system for
operation referring to Step
2 of DTC P0505 Diag.
Flow Table.
4 Was idle speed higher than specification in
Step 1?Go to Step 5. Go to Step 8.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-123
Fig. 1 for Step 105 Check A/C (input) signal circuit referring to Step
1 of Table B-5 A/C Signal Circuit Check, if
equipped. (A/C signal can be also checked by
using SUZUKI scan tool.)
Is it in good condition?Go to Step 6. Repair or replace A/C sig-
nal circuit or A/C system.
6 Check IAC system referring to Step 2 of DTC
P0505 Diag. Flow Table.
Is check result satisfactory?Go to Step 7. Go to Step 3 of DTC
P0505 Diag. Flow Table.
7 Was IAC duty less than about 3% (or more than
about 97% for OFF duty meter) in Step 1 of this
table?Check abnormal air inhal-
ing from air intake system,
PCV valve and EVAP
canister purge control
system.Check TP sensor (closed
throttle position) and ECT
sensor for performance.
If sensors are OK, substi-
tute a known-good ECM.
8 Is SUZUKI scan Tool available? Go to Step 9. Go to Step 10.
9 Check PNP signal (“D” range signal).
1) Connect SUZUKI scan tool to DLC with igni-
tion switch OFF.
2) Turn ignition switch ON and check PNP sig-
nal (“P/N” and “D” range) on display when
shifting selector lever to each range. See
Table 1.
Is check result satisfactory?Go to Step 11. Repair or replace.
10 Check PNP signal (“D” range signal).
1) Turn ignition switch ON.
2) Check voltage at terminal C41-14 (Case of
TYPE A. See NOTE) or G02-6 (Case of
TYOE B. See NOTE) of ECM connector
connected. See Fig. 1 and Table 1.
Is check result satisfactory?Go to Step 11. Repair or replace.
11 Check IAC system referring to Step 2 of DTC
P0505 Diag. Flow Table.
Is check result satisfactory?Go to Step 10. Go to Step 3 of DTC
P0505 Diag. Flow Table.
12 Was IAC duty more than about 30% (or less
than 70% for OFF duty meter) in Step 1 of this
table?Check parts or system
which can cause engine
low idle.
Accessory engine load
Clog of air passage
Etc.Substitute a known-good
ECM and recheck. Step Action Yes No
[A] : Case of TYPE A is shown (See NOTE)
[B] : Case of TYPE B is shown (See NOTE)