1999 SUZUKI GRAND VITARA display

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-51
TROUBLESHOOTING
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 Check IAT sensor and its circuit :
1) Connect scan tool with ignition switch OFF.
2) Turn ignition switch ON.
3) Check intake air temp. displayed on scan
tool.
Is – 40°C (– 40°F) or 165°C (329°F) indicated?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “INTERMIT-
TENT AND POOR CON-
NECTION” in Section 0A.
3 Check wire harness :
1) Disconnect IAT sensor connector with igni-
tion switch OFF.
2) Check for proper connection to IAT sensor
at “LT BLU” and “GRY/YEL” wire terminals.
If OK, then with ignition switch ON, is voltage
applied to “LT BLU” wire terminal about 4 – 6 V?Go to Step 4. “LT BLU” wire open or
short, or poor C51-3-1
connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.
4 Check wire harness :
1) Using service wire, connect IAT sensor con-
nector terminals.
2) Turn ignition switch ON and check intake air
temp. displayed on scan tool.
Is 165°C (329°F) indicated?Replace IAT sensor. “GRY/YEL” wire open or
poor C51-3-25 connec-
tion.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-53
TROUBLESHOOTING
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 Check ECT sensor and its circuit :
1) Connect scan tool with ignition switch OFF.
2) Turn ignition switch ON.
3) Check engine coolant temp. displayed on
scan tool.
Is – 40°C (– 40°F) or 164°C (327°F) indicated?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “INTERMIT-
TENT AND POOR CON-
NECTION” in Section 0A.
3 Check wire harness :
1) Disconnect ECT sensor connector with igni-
tion switch OFF.
2) Check for proper connection to ECT sensor
at “ORN/BLK” and “GRY/YEL” wire termi-
nals.
If OK, then with ignition switch ON, is voltage
applied to “ORN/BLK” wire terminal about 4 – 6
V?Go to Step 4. “ORN/BLK” wire open or
short, or poor C51-3-2
connection.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.
4 Check wire harness :
1) Using service wire, connect ECT sensor
connector terminals.
2) Turn ignition switch ON and check engine
coolant temp. displayed on scan tool.
Is 164°C (327°F) indicated?Replace ECT sensor. “GRY/YEL” wire open or
poor C51-3-23 connec-
tion.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-55
TROUBLESHOOTING
Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check TP sensor and its circuit.
1) Connect scan tool to DLC with ignition
switch OFF and then turn ignition switch
ON.
2) Check throttle valve opening percentage
displayed on scan tool.
Is it displayed 3% or less?
3) Check throttle valve opening percentage
displayed on scan tool while opening throttle
valve from idle position to full open position.
Is it displayed 96% or higher?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.
3 Check wire harness.
1) Disconnect connector from TP sensor with
ignition switch OFF.
2) Check for proper connection to TP sensor at
“GRY/RED”, “RED/GRN” and “GRY/YEL”
wire terminal.
3) If OK, then with ignition switch ON, check
voltage between each of “GRY/RED” or
“RED/GRN” wire terminals and body
ground.
Is voltage about 4 – 6 V at each terminal?Go to Step 4. “GRY/RED” wire open,
“GRY/RED” wire shorted
to ground circuit or power
circuit or “RED/GRN”
wire, “GRY/YEL” wire
open or shorted to ground
circuit or poor C51-3-13 or
C51-3-9 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.
4 Check TP sensor.
1) Check resistance between terminals of TP
sensor referring to “TP SENSOR” in Section
6E2.
Are measured values within specifications?“RED/GRN” wire shorted
to power circuit.
If wire is OK, substitute a
known-good ECM (PCM)
and recheck.Replace TP sensor.

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.

6-1-64 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
1) Connect scan tool with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data in ECM memory by using scan
tool and start engine.
3) Increase vehicle speed to 55 km/h (40 mph) or more.
4) Keep driving above vehicle speed till engine is warmed up completely (Changed of vehicle speed is permit-
ted in this step).
5) Keep driving 50 – 60 km/h (30 – 40 mph) for 8 min. or more.
6) Stop vehicle and check if pending DTC exists by using scan tool. If not, check if oxygen sensor heater moni-
toring test has completed by using scan tool. If not in both of above checks (i.e., no pending DTC and oxy-
gen sensor heater monitoring test not completed), check vehicle conditions (environmental) and repeat
Steps 3) through 6).
TROUBLESHOOTING
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-2 output voltage check :
1) Connect scan tool to DLC with ignition
switch OFF.
2) Drive vehicle about 35 mph, 55 km/h for 2
min. or more.
3) Stop vehicle and check HO2S-2 output volt-
age displayed on scan tool while repeating
racing engine.
Is over and below 0.3 V indicated?Go to Step 4. Go to Step 3.
3 HO2S-2 check :
1) With ignition switch OFF, disconnect HO2S-
2 coupler.
2) Connect voltmeter between “2” and “1” of
HO2S-2 coupler.
3) Start engine and check voltmeter while
repeating racing engine.
Is over and below 0.3 V indicated?“RED/BLK” or “GRY/YEL”
circuit open/short.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.Replace HO2S-2.
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 intermittent
referring to “INTERMIT-
TENT AND POOR CON-
NECTION” in Section 0A.Go to DTC P0171/P0172
Diag. Flow Table.

6-1-68 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
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/BLU” 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.

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.