2001 SUZUKI GRAND VITARA Owners Manual

6-1-56 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0121 Throttle Position Circuit Range/Performance Problem
WIRING DIAGRAM/CIRCUIT DESCRIPTION
Refer to DTC P0120.
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool and start
engine.
3) Increase vehicle speed to 60 km/h (40 mph).
4) Keep driving above vehicle speed for 5 min (Change of vehicle speed is permitted in this step).
5) Stop vehicle and run engine at idle speed for 1 min.
6) Increase vehicle speed till engine speed is reached 2,000 – 3,000 r/min in proper gear.
7) Keep driving at that engine speed for 30 sec or more (Engine speed is kept constant in this step).
8) Stop vehicle.
9) Repeat step 6) to 8).
10) Check pending DTC by using scan tool.DTC DETECTING CONDITION TROUBLE AREA
Throttle opening change is smaller than specification
while intake air volume changes and engine is running at
constant speed. (2 driving cycle detection logic)•TP sensor
•ECM (PCM)
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.
NOTE:
Check to make sure that following conditions are satisfied when using this “DTC CONFIRMATION
PROCEDURE”.
Intake air temp. : – 8°C (18°F) or higher
Engine coolant temp. : – 8 – 110°C (18 – 230°F)
Altitude barometric pressure : 2400 m, 8000 ft or less (560 mmHg (75 kPa) or more)

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-57
TROUBLESHOOTING
Fig. for Steps 4 and 5Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE
DIAG. FLOW TABLE”
in this section.
2 Is there a DTC related to TP sensor (DTC P0120)? Go to applicable DTC
Diag. Flow Table.Go to Step 3.
3 Do you have SUZUKI scan tool ? Go to Step 4. Go to Step 5.
4 Check TP sensor and its circuit (using SUZUKI
scan tool) :
1) Turn ignition switch OFF and connect SUZUKI
scan tool to DLC.
2) Turn ignition switch ON and check TP sensor
output voltage when throttle valve is at idle posi-
tion and fully opened.
Does voltage vary within specified value linearly as
shown in the figure?Substitute a known-good
ECM (PCM) and recheck.Go to Step 6.
5 Check TP sensor and its circuit (not using SUZUKI
scan tool) :
1) Turn ignition switch ON.
2) Check voltage at terminal C51-3-9 of ECM con-
nector connected, when throttle valve is at idle
position and fully opened.
Does voltage vary within specified value linearly as
shown in the figure?If voltmeter was used,
check terminal C51-3-9 for
poor connection.
If OK, substitute a known-
good ECM (PCM) and
recheck.Go to Step 6.
6 Check TP sensor :
1) Turn ignition switch OFF.
2) Disconnect TP sensor connector.
3) Check for proper connection to TP sensor at
each terminal.
4) If OK, check TP sensor for resistance referring
to “TP SENSOR” in Section 6E2.
Is check result satisfactory?High resistance in “GRY/
RED”, “RED/GRN” or
“GRY/YEL” circuit.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.Replace TP sensor.
1. Voltage
2. Throttle opening
3. At idle position
4. Fully open

6-1-58 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0130 (DTC No.13) HO2S-1 (Bank 1) Circuit Malfunction or No Activity
Detected
WIRING DIAGRAM
DTC DETECTING CONDITION AND TROUBLE AREA
1. HO2S heater relay
2. ECM (PCM)
3. HO2S-1 (Bank-1)
NOTE:
For vehicle with monitor connector, DTC will set when following only (*) mark condition is detected.
DTC DETECTING CONDITION TROUBLE AREA
Any one of the following conditions are detected in idle state while running
under driving conditions described for “DTC CONFIRMATION PROCEDURE”.
• 4.5 V or more HO2S circuit voltage is detected, when 5 V power is con-
nected to HO2S circuit in ECM (PCM), or
• Max. output voltage of HO2S is 0.6 V or lower on average and its minimum
voltage on average is 0.3 V or lower.
• Min. output voltage of HO2S is over 3.0 V or
• Max. output voltage of HO2S is 0.74 V or higher on average and its min.
voltage on average is 0.33 V or higher.
• *Output voltage of HO2S-1 does not exceed 0.45 V for specified time.
(2 driving cycle detection logic)HO2S-1 or its circuit.
Fuel system
ECM (PCM)

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-59
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool and start
engine.
3) Increase vehicle speed to 55 km/h (35 mph) or more.
4) Keep driving above vehicle speed for 2 min. or more (Change of vehicle speed is permitted in this step).
5) Stop vehicle, and run engine at idle speed for 1 min.
6) Check if pending DTC exists by using scan tool. If not, check if oxygen sensor monitoring test has completed
by using scan tool. If not in both of above checks (i.e., no pending DTC and oxygen sensor monitoring test
not completed), check vehicle condition (environmental) and repeat step 3) through 6).
TROUBLESHOOTING
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.
NOTE:
Check to make sure that following conditions are satisfied when using this “DTC CONFIRMATION
PROCEDURE”.
Intake air temp. : – 8°C (18°F) or higher
Engine coolant temp. : – 8 – 110°C (18 – 230°F)
Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg (75 kPa) or more)
Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE
DIAG. FLOW
TABLE” in this sec-
tion.
2 HO2S-1 output voltage check :
1) Connect scan tool to DLC with ignition switch OFF.
2) Warm up engine to normal operating temperature and
keep it at 2000 r/min. for 60 sec.
3) Repeat racing engine (Repeat depressing accelerator
pedal 5 to 6 times continuously to enrich A/F mixture
and take foot off from pedal to enlean and check HO2S
output voltage displayed on scan tool. See Fig.
Is over 0.6 V and below 0.3 V indicated?Go to Step 4. Go to Step 3.
3 HO2S-1 check :
1) With ignition switch OFF, disconnect HO2S-1 connec-
tor.
2) Check for proper connection to HO2S-1 at each termi-
nal.
3) If OK, connect voltmeter “1” and “2” terminal of HO2S-1
connector.
4) Start engine and check voltmeter while repeating rac-
ing engine.
Is over 0.6 V and below 0.3 V indicated?“RED” or “GRY/
YEL” circuit open or
short.
If wire and connec-
tions are OK, sub-
stitute a known-
good ECM (PCM)
and recheck.Replace HO2S-1.

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) 6-1-61
DTC P0135 HO2S-1 (Bank 1) Heater Circuit Malfunction
WIRING DIAGRAM
Refer to DTC P0130.
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
1) Connect scan tool with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool and run
engine at idle speed for 5 min.
3) Check pending DTC by using scan tool.
TROUBLESHOOTING
DTC DETECTING CONDITION TROUBLE AREA
Following condition is detected when HO2S heater is
electrically live (2 driving cycle detection logic).
• Current of HO2S heater is 5.3 A or more or less than
0.09 A, or
• Voltage of HO2S heater is 14.0 V or higher or lower
than 11.7 V.HO2S-1 heater circuit
HO2S-1 heater
ECM (PCM)
HO2S heater relay
NOTE:
Check to make sure that following conditions are satisfied when using this “DTC CONFIRMATION
PROCEDURE”.
Intake air temp. : – 8°C (18°F) or higher
Engine coolant temp. : – 8 – 110°C (18 – 230°F)
Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg (75 kPa) or more)
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 HO2S-1 heater check :
1) Disconnect HO2S-1 coupler with ignition
switch OFF.
2) Check resistance between “3” and “4” termi-
nal of HO2S-1 coupler.
HO2S-1 heater resistance :
5.0 – 6.4
Ω
ΩΩ Ω (at 20°C (68°F))
Is it within above specification?Go to Step 3. Replace HO2S-1.
3 HO2S heater power supply check :
1) With ignition switch ON leaving engine OFF,
check voltage between E139-3 and ground,
E139-1 and ground. (See Fig.)
Is each voltage 10 – 14 V?Go to Step 4. “HO2S”, and/or “IG
METER” fuse blown.
If OK, faulty “BLK/WHT”
wire or “BLU/WHT” wire.

6-1-62 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Fig. for STEP 34 HO2S heater control circuit check :
1) With ignition switch OFF, install HO2S
heater relay.
2) With ignition switch ON leaving engine OFF,
check voltage between C51-2-4 and
ground.
Is the voltage 10 – 14 V?Substitute a known-good
ECM (PCM) and recheck.Faulty HO2S heater relay
or “BLK” wire open, “BLU”
wire open or shorted to
ground circuit
or
“GRY” wire open or
shorted to ground circuit.
If OK, substitute a known-
good ECM (PCM) and
recheck. Step Action Yes No
a. HO2S heater relay

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-63
DTC P0136 HO2S-2 (Bank 1) Circuit Malfunction
WIRING DIAGRAM
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
1. HO2S heater relay
2. ECM (PCM)
3. HO2S-2 (Bank-1)
DTC DETECTING CONDITION TROUBLE AREA
DTC will set when any one of following conditions is detected (2 driving
cycle detection logic).
• 4.5 V or more HO2S circuit voltage is detected when 5 V power is con-
nected to HO2S circuit in ECM (PCM).
• While running with A/F feed back, average output voltage during speci-
fied time is too high or too low.
or
• While running with A/F feed back, max output voltage during specified
time is lower than specified value or min. output voltage during speci-
fied time is higher than specified value.• HO2S-2 or its circuit
• Fuel system
•ECM (PCM)
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.