2001 SUZUKI GRAND VITARA ESP

6-1-32 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Improper engine idling
or engine fails to idleFaulty spark plug Spark plugs in Section 6F2.
Faulty ignition coil with ignitor Ignition coil in Section 6F2.
Fuel pressure out of specification “DIAG. FLOW TABLE B-3” in this
section.
Engine overheating Refer to “OVERHEATING” in this
table.
Maladjusted TP sensor installation angle if
adjustableTP sensor in Section 6E2.
Faulty idle air control system “DIAG. FLOW TABLE B-4” in this
section.
Faulty FIA (fast idle air) valve FIA valve in Section 6E2.
Faulty evaporative emission control system EVAP control system in Section
6E2.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty injector Fuel injection in Section 6E2.
Faulty ECT sensor, TP sensor or MAF sensor ECT sensor, TP sensor or MAF
sensor in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Refer to the same item in “HARD
STARTING” of this table.
Malfunctioning PCV valve PCV system inspection in Section
6E2.
Engine hesitates
(Momentary lack of
response as the accel-
erator is depressed.
Can occur at all vehi-
cle speeds.
Usually most severe
when first trying to
make the vehicle
move, as from a stop
sign.)Spark plug faulty or plug gap as out of adjust-
mentSpark plugs in Section 6F2.
Fuel pressure out of specification
(clogged fuel filter, faulty fuel pressure regula-
tor, clogged fuel filter, hose or pipe)“DIAG. FLOW TABLE B-3” in this
section.
Engine overheating Refer to “OVERHEATING” in this
table.
Faulty EGR system “DTC P0400 DIAG. FLOW TABLE”
in this section.
Faulty injector Fuel injector in Section 6E2.
Faulty TP sensor, ECT sensor or MAF sensor TP sensor, ECT sensor or MAF
sensor in Section 6E2.
Faulty ECM (PCM) Inspection of ECM (PCM) and its
circuit in this section.
Low compression Refer to the same item in “HARD
STARTING” of this table. Condition Possible Cause Correction

6-1-60 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Fig. for Step 2
DTC P0133 HO2S-1 (Bank 1) Circuit Slow Response
WIRING DIAGRAM/CIRCUIT DESCRIPTION
Refer to DTC P0130.
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
Refer to DTC P0130.
TROUBLESHOOTING
4 Short term fuel trim check :
1) Run engine at 2000 r/min. for 60 sec.
2) With engine idling, check short term fuel trim displayed
on scan tool.
Is it within – 20 to +20 %?Intermittent trouble
or faulty ECM
(PCM).
Check for intermit-
tent referring to
“INTERMITTENT
AND POOR CON-
NECTION” in Sec-
tion 0A.Go to DTC P0171/
P0172 Diag. Flow
Table. Step Action Yes No
1. Normal
2. NG
DTC DETECTING CONDITION TROUBLE AREA
Following conditions are detected in idle state while running under driving
conditions described for “DTC CONFIRMATION PROCEDURE”.
Hi/Lo cycle (TRANS TIME displayed on scan tool) of HO2S-1 output voltage
is longer than specification or response rates of Hi → Lo and Lo → Hi
(TRANS TIME displayed as R → L threshold V or L → R threshold V on scan
tool) are longer than specification.
(2 driving cycle detection logic)HO2S-1
ECM (PCM)
Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE” in this
section.
2 1) Replace HO2S-1 and recheck.
Is DTC P0133 detected?Substitute a known-good
ECM (PCM) and recheck.HO2S-1 malfunction.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-69
Fig. for Step 2
DTC P0153 HO2S-1 (Bank 2) Circuit Slow Response
WIRING DIAGRAM/CIRCUIT DESCRIPTION
Refer to DTC P0150.
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
Refer to DTC P0150.
TROUBLESHOOTING
4 Short term fuel trim check :
1) Run engine at 2000 r/min. for 60 sec.
2) With engine idling, check short term fuel trim displayed
on scan tool.
Is it within – 20 to +20 %?Intermittent trouble
or faulty ECM
(PCM).
Check for intermit-
tent referring to
“INTERMITTENT
AND POOR CON-
NECTION” in Sec-
tion 0A.Go to DTC P0174/
P0175 Diag. Flow
Table. Step Action Yes No
1. Normal
2. NG
DTC DETECTING CONDITION TROUBLE AREA
Following conditions are detected in idle state while running under driving
conditions described for “DTC CONFIRMATION PROCEDURE”.
Hi/Lo cycle (TRANS TIME displayed on scan tool) of HO2S-1 output voltage
is longer than specification or response rates of Hi → Lo and Lo → Hi
(TRANS TIME displayed as R → L threshold V or L → R threshold V on scan
tool) are longer than specification.
(2 driving cycle detection logic)HO2S-1
ECM (PCM)
Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE” in this
section.
2 1) Replace HO2S-1 and recheck.
Is DTC P0153 detected?Substitute a known-good
ECM (PCM) and recheck.HO2S-1 malfunction.

6-1-94 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0420 Catalyst System Efficiency Below Threshold (Bank 1)
SYSTEM DIAGRAM
CIRCUIT DESCRIPTION
Exhaust oxygen concentration at the pre-catalyst and the post-catalyst of WU-TWC is detected from HO2S-1
and HO2S-2 respectively and accordingly ECM (PCM) controls the closed loop which then controls the fuel
injection volume. (Refer to Section 6E2.) While the above control is going on and if WU-TWC is in good condi-
tion, the output voltage of HO2S-2 is maintained at specified level. As WU-TWC becomes deteriorated, even
when the above control is going on, the exhaust gas which has passed WU-TWC then passes HO2S-2 at the
exhaust oxygen concentration similar to that of the pre-catalyst without being oxygenated or converted. Thus,
waveforms of HO2S-1 and HO2S-2 output voltages become alike. ECM (PCM) judges deterioration of WU-TWC
by comparing waveforms of HO2S-1 and HO2S-2.
DTC DETECTING CONDITION AND TROUBLE AREA
1. HO2S-1 (Bank-1) 4. TWC
2. HO2S-2 (Bank-1) 5. ECM (PCM)
3. WU-TWC
DTC DETECTING CONDITION TROUBLE AREA
While running under conditions described for DTC CON-
FIRMATION PROCEDURE, output waveform of HO2S-1
becomes similar to that of HO2S-2.
(2 driving cycle detection logic)• Exhaust gas leakage
• Warm up three way catalytic converter
• Heated oxygen sensor – 2 or its circuit
•ECM (PCM)

6-1-96 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0430 Catalyst System Efficiency Below Threshold (Bank 2)
SYSTEM DIAGRAM
CIRCUIT DESCRIPTION
Exhaust oxygen concentration at the pre-catalyst and the post-catalyst of WU-TWC is detected from HO2S-1
and HO2S-2 respectively and accordingly ECM (PCM) controls the closed loop which then controls the fuel
injection volume. (Refer to Section 6E2.) While the above control is going on and if WU-TWC is in good condi-
tion, the output voltage of HO2S-2 is maintained at specified level. As WU-TWC becomes deteriorated, even
when the above control is going on, the exhaust gas which has passed TWC then passes HO2S-2 at the
exhaust oxygen concentration similar to that of the pre-catalyst without being oxygenated or converted. Thus,
waveforms of HO2S-1 and HO2S-2 output voltages become alike. ECM (PCM) judges deterioration of WU-TWC
by comparing waveforms of HO2S-1 and HO2S-2.
DTC DETECTING CONDITION AND TROUBLE AREA
1. HO2S-1 (Bank-2) 4. TWC
2. HO2S-2 (Bank-2) 5. ECM (PCM)
3. WU-TWC
DTC DETECTING CONDITION TROUBLE AREA
While running under conditions described for DTC CON-
FIRMATION PROCEDURE, output waveform of HO2S-1
becomes similar to that of HO2S-2.
(2 driving cycle detection logic)• Exhaust gas leakage
• Warm up three way catalytic converter
• Heated oxygen sensor – 2 or its circuit
•ECM (PCM)

6-1-118 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
INSPECTION
Step Action Yes No
1 Check injector for operating sound :
Using sound scope, check each injector for
operating sound at engine cranking.
Do all 6 injectors make operating sound?Go to Step 2. Go to Step 3.
2 Wire harness check :
1) Remove ECM (PCM) cover and disconnect
connectors from ECM (PCM).
2) Check for resistance between following ter-
minals of ECM (PCM) connector discon-
nected.
Fuel injector and its circuit resistance (C51-
2-1 – C51-3-4, C51-2-2 – C51-3-4, C51-2-8 –
C51-3-4, C51-2-9 – C51-3-4, C51-2-21 – C51-
3-4 and C51-2-22 – C51-3-4) :
14.2 – 14.8
Ω
ΩΩ Ω at 20°C (68°F)
Is check result as specified?Fuel injector circuit is in
good condition.“PNK”, “PNK/BLK”, “PNK/
GRN”, “PNK/BLU”, “GRY/
GRN” and “GRY/BLK”
shorted each other.
3 Does none of 6 injectors make operating sound
at Step 1?Go to Step 4. Check coupler connec-
tion and wire harness of
injector not making oper-
ating sound and injector
itself (Refer to “FUEL
INJECTOR INSPEC-
TION” in Section 6E2).
4 Check power circuit of injectors for open and
short.
Is it normal?Check all 6 injectors for
resistance respectively.
It resistance is OK, substi-
tute a known-good ECM
(PCM) and recheck.Power circuit open or
short.

6-1-124 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Table B-6 A/C Condenser Fan Motor Relay Control System Inspection (If
Equipped)
WIRING DIAGRAM
INSPECTION
1. To ignition switch 3. A/C fuse 5. A/C condenser fan motor
2. Main fuse 4. A/C condenser fan motor relay 6. ECM (PCM)
WARNING:
Keep hands, tools, and clothing away from A/C condenser fan to help prevent personal injury. This
fan is electric and can come on whether or not the engine is running. The fan can start automatically
in response to the ECT sensor with the ignition switch in the “ON” position.
Step Action Yes No
1 1) Check DTC referring to “DTC CHECK” in this sec-
tion.
Is there any malfunction DTC?Go to applicable DTC
Diag. Flow Table.Go to Step 2.
2 1) Check A/C condenser fan for operation.
A/C condenser fan should be operated under follow-
ing condition A or B only.
A : When engine is running and A/C is operating.
B : When engine coolant temp. is 113°C (235°F) or
more with ignition switch ON.
Is check result as specified?This system is in
good condition.Go to Step 3.
3 1) Remove ECM (PCM) cover.
2) Check voltage between E61-22 terminal of ECM
(PCM) connected coupler and ground.
Other than conditions A and B in Step 2 :
10 – 14 V
Under condition A or B in Step 2 :
0 – 1 V
Is check result as specified?Fuse blown, “RED”,
“RED/BLK” or “RED/
BLU” circuit open,
malfunction of con-
denser fan motor or
relay.“YEL/GRN” circuit
open, “YEL/BLU” cir-
cuit open or short, or
relay malfunction.
If above are OK, sub-
stitute a known-good
ECM (PCM) and
recheck.

ENGINE MECHANICAL (H27 ENGINE) 6A2-25
3) Install piston rings to piston :
•As shown in the figure, 1st and 2nd rings have “RN” or “R”
mark respectively. When installing these piston rings to pis-
ton, direct marked side of each ring toward top of piston.
•1st rings differs from 2nd ring in thickness, shape and color
of surface contacting cylinder wall.
Distinguish 1st ring from 2nd ring by referring to the figure.
•When installing oil ring, install spacer first and then 2 rails.
4) After installing three rings (1st, 2nd and oil rings), distribute
their end gaps as shown in the figure. NOTE:
Install circlip with its cut part facing as shown in the
figure.
Install so that circlip end gap comes within such range
as indicated by arrow “A”.
1. Piston
2. Arrow mark
3. Connecting rod
4. Oil hole
5. Crankshaft pulley side
1. 1st ring
2. 2nd ring
3. Oil ring
1. Arrow mark
2. 1st ring end gap
3. 2nd ring end gap and oil ring spacer gap
4. Oil ring upper rail gap
5. Oil ring lower rail gap
6. Intake side
7. Exhaust side