
6-1-10 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DATA LINK CONNECTOR (DLC)
DLC (1) is in compliance with SAEJ1962 in its installation posi-
tion, the shape of connector and pin assignment.
K line of ISO 9141 is used for SUZUKI scan tool to communicate
with ECM (PCM), ABS control module and air bag SDM. SUZUKI
serial data line is used for SUZUKI scan tool to communicate with
Immobilizer control module.
Precaution in Diagnosing Trouble
• Don’t disconnect couplers from ECM (PCM), battery cable from battery, ECM (PCM) ground wire harness
from engine or main fuse before confirming diagnostic information (DTC, freeze frame data, etc.) stored in
ECM (PCM) memory. Such disconnection will erase memorized information in ECM (PCM) memory.
• Diagnostic information stored in ECM (PCM) memory can be cleared as well as checked by using SUZUKI
scan tool or generic scan tool. Before using scan tool, read its Operator’s (Instruction) Manual carefully to
have good understanding as to what functions are available and how to use it.
• Priorities for diagnosing troubles (Vehicle without monitor connector)
If two or more diagnostic trouble codes (DTCs) are stored, proceed to the flow table of the DTC which was
detected earliest in the order and follow the instruction in that table.
If no instructions are given, troubleshoot diagnostic trouble codes according to the following priorities.
– Diagnostic trouble codes (DTCs) other than DTC P0171/P0172/P0174/P0175 (Fuel system too lean/too
rich), DTC P0300/P0301/P0302/P0303/P0304/P0305/P0306 (Misfire detected) and DTC P0400 (EGR
flow malfunction)
– DTC P0171/P0172/P0174/P0175 (Fuel system too lean/too rich) and DTC P0400 (EGR flow malfunction)
– DTC P0300/P0301/P0302/P0303/P0304/P0305/P0306 (Misfire detected)
• Be sure to read “PRECAUTIONS FOR ELECTRICAL CIRCUIT SERVICE” in Section 0A before inspection
and observe what is written there.
• ECM (PCM) Replacement
When substituting a known-good ECM (PCM), check for following conditions. Neglecting this check may
cause damage to a known-good ECM (PCM).
– Resistance value of all relays, actuators is as specified respectively.
– MAF sensor, MAP sensor and TP sensor are in good condition and none of power circuits of these sen-
sors is shorted to ground.
2. B+
3. SUZUKI Serial data line
4. K line of ISO 9141
5. Body ground
6. ECM ground 

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-15
STEP 9. TROUBLESHOOTING FOR DTC
Based on the DTC indicated in Step 6 or 7 and referring to the applicable DTC diag. flow table in this section,
locate the cause of the trouble, namely in a sensor, switch, wire harness, connector, actuator, ECM (PCM) or
other part and repair or replace faulty parts.
STEP 10. CHECK FOR INTERMITTENT PROBLEM
Check parts where an intermittent trouble is easy to occur (e.g., wire harness, connector, etc.), referring to
“INTERMITTENT AND POOR CONNECTION” in Section 0A and related circuit of DTC recorded in step 2.
STEP 11. FINAL CONFIRMATION TEST
Confirm that the problem symptom has gone and the engine is free from any abnormal conditions. If what has
been repaired is related to the DTC, clear the DTC once, perform DTC confirmation procedure and confirm that
no malfunction DTC (a normal code) is indicated. 
![SUZUKI GRAND VITARA 2001 2.G Owners Manual 6-1-18 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
[Without using scan tool]
1) Turn the ignition switch OFF position.
2) Disconnect battery negative cable for specified time below to
erase  SUZUKI GRAND VITARA 2001 2.G Owners Manual 6-1-18 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
[Without using scan tool]
1) Turn the ignition switch OFF position.
2) Disconnect battery negative cable for specified time below to
erase](/manual-img/20/7584/w960_7584-178.png)
6-1-18 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
[Without using scan tool]
1) Turn the ignition switch OFF position.
2) Disconnect battery negative cable for specified time below to
erase diagnostic trouble code stored in ECM memory and
reconnect it.
Time required to erase DTC:
Diagnostic Trouble Code (DTC) Table
Ambient
temperatureTime to cut power to ECM
Over 0°C (32°F) 30 sec. or longer
Under 0°C
(32°F)Not specifiable.
Select a place with higher than 0°C
(32°F) temperature.
DTC NO. DETECTED ITEMDETECTING CONDITION
(DTC will set when detecting : )MIL
(vehicle
without 
monitor 
connector)MIL
(vehicle 
with 
monitor
connector)
P0100
(No.34)
Mass air flow circuit malfunc-
tionSensor output too low
1 driving 
cycle1 driving 
cycle
P0100
(No.33)Sensor output too high
P0110
(No.25)
Intake air temp. circuit mal-
functionIntake air temp. circuit low input
1 driving 
cycle1 driving 
cycle
P0110
(No.23)Intake air temp. circuit high input
P0115
(No.15)
Engine coolant temp. circuit 
malfunctionEngine coolant temp. circuit low input
1 driving 
cycle1 driving 
cycle
P0115 
(No.14)Engine coolant temp. circuit high input
P0120 
(No.22)
Throttle position circuit mal-
functionThrottle position circuit low input
1 driving 
cycle1 driving 
cycle
P0120 
(No.21)Throttle position circuit high input
P0121Throttle position circuit perfor-
mance problemPoor performance of TP sensor2 driving 
cyclesNot 
applicable
*P0130HO2S circuit malfunction
(Bank 1 - Sensor 1)Min. output voltage of HO2S-1 is 
higher than specification.
2 driving 
cyclesNot 
applicable Min. output voltage of HO2S-1 is 
lower than specification.
Output voltage of HO2S-1 fails to go 
above specification.
**P0130 
(No.13)HO2S (Bank 1 - Sensor 1) no 
activity detectedOutput voltage of HO2S-1 fails to go 
above specification (or HO2S-1 cir-
cuit open).2 driving 
cycles2 driving 
cycles 

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-19
P0133HO2S circuit slow response
(Bank 1 - Sensor 1)Response time of HO2S-1 output volt-
age between rich and lean is longer 
than specification.2 driving 
cyclesNot
applicable
P0135HO2S heater circuit malfunc-
tion (Bank 1 - Sensor 1)Terminal voltage is lower than specifi-
cation at heater OFF or it is higher at 
heater ON.2 driving 
cyclesNot
applicable
P0136HO2S circuit malfunction 
(Bank 1 - Sensor 2)Max. voltage of HO2S-2 is lower than 
specification or its min. voltage is 
higher than specification.2 driving 
cyclesNot
applicable
P0141HO2S heater circuit malfunc-
tion (Bank 1 - Sensor 2)Terminal voltage is lower than specifi-
cation at heater OFF or it is higher at 
heater ON.2 driving 
cyclesNot
applicable
*P0150HO2S circuit malfunction 
(Bank 2 - sensor 1)Min. output voltage of HO2S-1 is 
higher than specification.
2 driving 
cyclesNot
applicable Min. output voltage of HO2S-1 is 
lower than specification.
Output voltage of HO2S-1 fails to go 
above specification.
**P0150 
(No.26)HO2S (Bank 2 - Sensor 1) no 
activity detectedOutput voltage of HO2S-1 fails to go 
above specification (or HO2S-1 cir-
cuit open).2 driving 
cycles2 driving 
cycles
P0153HO2S circuit slow response 
(Bank 2 - Sensor 1)Response time HO2S-1 output volt-
age between rich and lean is longer 
than specification.2 driving 
cyclesNot
applicable
P0155HO2S heater circuit malfunc-
tion (Bank 2 - Sensor 1)Terminal voltage i lower than specifi-
cation at heater OFF or it is higher at 
heater ON.2 driving 
cyclesNot
applicable
P0156HO2S circuit malfunction 
(Bank 2 - Sensor 2)Max. voltage of HO2S-2 is lower than 
specification or its min. voltage is 
higher than specification.2 driving 
cyclesNot
applicable
P0161HO2S heater circuit malfunc-
tion (Bank 2 - Sensor 2)Terminal voltage is lower than specifi-
cation at heater OFF or it is higher at 
heater ON (or heater circuit or short).2 driving 
cyclesNot
applicable
P0171 Fuel system too lean (Bank 1)Short term fuel trim or total fuel trim 
(short and long terms added) is larger 
than specification for specified time or 
longer. (Fuel trim toward rich side is 
large.)2 driving 
cyclesNot
applicable
P0172 Fuel system too rich (Bank 1)Short term fuel trim or total fuel trim 
(short and long terms added) is 
smaller than specification for specified 
time or longer. (Fuel trim toward lean 
side is large.)2 driving 
cyclesNot
applicable DTC NO. DETECTED ITEMDETECTING CONDITION
(DTC will set when detecting : )MIL
(vehicle
without 
monitor 
connector)MIL
(vehicle 
with 
monitor
connector) 

6-1-20 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
P0174 Fuel system too lean (Bank 2)Short term fuel trim or total fuel trim 
(short and long terms added) is larger 
than specification for specified time or 
longer. (Fuel trim toward rich side is 
large.)2 driving 
cyclesNot
applicable
P0175 Fuel system too rich (Bank 2)Short term fuel trim or total fuel trim 
(short and long terms added) is 
smaller than specification for specified 
time or longer. (Fuel trim toward lean 
side is large.)2 driving 
cyclesNot
applicable
P0300
P0301
P0302
P0303
P0304
P0305
P0306Random misfire detected
Cylinder 1 misfire detected
Cylinder 2 misfire detected
Cylinder 3 misfire detected
Cylinder 4 misfire detected
Cylinder 5 misfire detected
Cylinder 6 misfire detectedMisfire of such level as to cause dam-
age to three way catalystMIL flashing 
during mis-
fire detec-
tionNot
applicable
Misfire of such level as to deteriorate 
emission but not to cause damage to 
three way catalyst2 driving 
cyclesNot
applicable
P0325 
(No.43)Knock sensor circuit malfunc-
tionSensor output too low
1 driving 
cycle1 driving 
cycle
Sensor output too high
P0335Crankshaft position sensor cir-
cuit malfunctionNo signal during engine running and 
CMP sensor signal inputting1 driving 
cycleNot
applicable
P0340 
(No.42)Camshaft position sensor cir-
cuit malfunctionNo signal for 3 sec. during engine 
cranking, REF signal pattern incor-
rect or POS signal voltage too high or 
too low1 driving 
cycleNot
applicable
P0400Exhaust gas recirculation flow 
malfunction detectedExcessive or insufficient EGR flow.2 driving 
cyclesNot
applicable
P0403 
(No.51)EGR valve circuit malfunctionEGR valve electrical circuit open or 
shot to ground1 driving 
cycle1 driving 
cycle
P0420Catalyst system efficiency 
below threshold (Bank 1)Output waveforms of HO2S-1 and 
HO2S-2 are similar.
(Time from output voltage change of 
HO2S-1 to that of HO2S-2 is shorter 
than specification.)2 driving 
cyclesNot
applicable
P0430Catalyst system efficiency 
below threshold (Bank 2)Output waveforms of HO2S-1 and 
HO2S-2 are similar.
(Time from output voltage change of 
HO2S-1 to that of HO2S-2 is shorter 
than specification.)2 driving 
cyclesNot
applicable
P0443Purge control valve circuit 
malfunctionPurge control valve circuit is open or 
shorted to ground.2 driving 
cyclesNot
applicable
P0500 
(No.24)Vehicle speed sensor mal-
functionNo signal while running in “D” range 
or during fuel cut at decelerating.2 driving 
cycles1 driving 
cycle DTC NO. DETECTED ITEMDETECTING CONDITION
(DTC will set when detecting : )MIL
(vehicle
without 
monitor 
connector)MIL
(vehicle 
with 
monitor
connector) 

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-21
For A/T system (Refer to Section 7B1 for diagnosis)
P0505Idle air control system mal-
functionDifference between desired idle speed 
and actual idle speed continues to 
exceed specified value for longer than 
specified time.2 driving 
cyclesNot
applicable
P0601 
(No.71)Internal control module mem-
ory check sum errorData write error (or check sum error) 
when written into ECM1 driving 
cycle1 driving 
cycle
P1408Manifold absolute pressure 
sensor circuit malfunctionManifold absolute pressure sensor 
output voltage is higher or lower than 
specified value (or sensor circuit 
shorted to ground or open).2 driving 
cyclesNot
applicable
P1450Barometric pressure sensor 
circuit malfunctionBarometric pressure is lower or higher 
than specification.1 driving 
cycleNot
applicable
P1451Barometric pressure sensor 
performance problemDifference between intake manifold 
pressure and barometric pressure is 
larger than specification.2 driving 
cyclesNot
applicable
P1500Engine starter signal circuit 
malfunctionEngine starts with no starter signal or 
signal input during long period after 
start.2 driving 
cyclesNot
applicable
P1510ECM back-up power supply 
malfunctionNo back-up power after starting 
engine.1 driving 
cycleNot
applicable DTC NO. DETECTED ITEMDETECTING CONDITION
(DTC will set when detecting : )MIL
(vehicle
without 
monitor 
connector)MIL
(vehicle 
with 
monitor
connector)
DTC NO. DETECTED ITEMDETECTING CONDITION
(DTC will set when detecting : )MIL
(vehicle
without 
monitor 
connector)MIL
(vehicle 
with 
monitor
connector)
P0705 
(No.72)Transmission range switch cir-
cuit malfunctionMultiple signals inputted simulta-
neously or P, R, N, D, 2 or L range sig-
nal not inputted while running at 
60km/h or more.2 driving 
cyclesNot
applicable
P0715 
(No.76)Input speed sensor circuit 
malfunctionInput speed sensor signal is lower 
than specification while running.2 driving 
cyclesNot
applicable
P0720 
(No.75)Output speed sensor circuit 
malfunctionOutput speed sensor signal not input-
ted while VSS signal being inputted.2 driving 
cyclesNot
applicable
P0741TCC (lock-up) solenoid perfor-
mance or stuck offActual TCC operation does not agree 
with ON/OFF control from PCM to 
TCC.2 driving 
cyclesNot
applicable
P0743 
(No.65) 
(No.66)TCC (lock-up) solenoid electri-
calMonitor signal OFF is detected when 
TCC control solenoid is ON or monitor 
signal ON is detected when it is OFF.1 driving 
cycleNot
applicable
P0751Shift solenoid A (#1) perfor-
mance or stuck offGear change control from PCM to A/T 
does not agree with actual gear posi-
tion of A/T.2 driving 
cyclesNot
applicable 

6-1-22 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
For immobilizer control system (Refer to Section 8G for diagnosis) 
P0753 
(No.61) 
(No.62)Shift solenoid A (#1) electricalMonitor signal OFF is detected when 
shift solenoid A (#1) is ON or monitor 
signal ON is detected when it is OFF.1 driving 
cycleNot
applicable
P0756Shift solenoid B (#2) perfor-
mance or stuck offGear change control from PCM to A/T 
does not agree with actual gear posi-
tion of A/T.2 driving 
cyclesNot
applicable
P0758 
(No.63) 
(No.64)Shift solenoid B (#2) electricalMonitor signal OFF is detected when 
shift solenoid B (#2) is ON or monitor 
signal ON is detected when it is OFF.1 driving 
cycleNot
applicable
P18754WD low switch circuit mal-
functionDifference between vehicle speed 
detected by VSS and vehicle speed 
detected by output speed sensor and 
compensated by 4WD low switch is 
larger than specification.2 driving 
cyclesNot
applicable DTC NO. DETECTED ITEMDETECTING CONDITION
(DTC will set when detecting : )MIL
(vehicle
without 
monitor 
connector)MIL
(vehicle 
with 
monitor
connector)
DTC NO. DETECTED ITEMDETECTING CONDITION
(DTC will set when detecting : )MIL
(vehicle
without 
monitor 
connector)MIL
(vehicle 
with 
monitor
connector)
P1620 
(No.84)ECU code not registered
Refer to Section 8G P1621 
(No.83)NO ECU code transmitted 
from Immobilizer Control Mod-
ule
P1622 
(No.82)Fault ECM
P1623 
(No.81)ECU code not matched
NOTE:
DTC NO. with (*) is detected only vehicle without monitor connector.
DTC No. with (**) is detected only vehicle with monitor connector.
For ( ) marked No. in DTC column, it is used for vehicle with monitor connector.
DTC No.12 appears when none of the other codes is identified. 

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-23
Fail-Safe Table
When any of the following DTCs is detected, ECM (PCM) enters fail-safe mode as long as malfunction continues
to exist but that mode is canceled when ECM (PCM) detects normal condition after that.
DTC NO. TROUBLE AREA FAIL SAFE OPERATION
P0100 
(No.33, 34)MAF SENSOR• Injector drive time (fuel injection volume) is determined according to 
throttle valve opening and engine speed.
• EGR valve stops.
• Air flow of IAC valve is limited.
P0110 
(No.23, 25)IAT SENSOR Each control is performed on the basis of 22.1°C intake air temp.
P0115 
(No.14, 15)ECT SENSOR• Each control except 4-A/T is performed on the basis of 29.9°C engine 
coolant temp.
• 4-A/T control is performed assuming 31°C (engine warmed up) or 
higher after 15 min. from engine start.
P0120 
(No.21, 22)TP SENSOR• Each control except 4-A/T is performed on the basis of 124.5° throttle 
valve opening.
• 4-A/T control is performed on the basis of 0° throttle valve opening.
P0460 FUEL LEVEL SENSOR Each control is performed in the basis of full fuel level.
P0500VEHICLE SPEED 
SENSORAir flow of IAC valve is limited.
P1450BAROMETRIC
PRESSURE SENSOREach control is performed based on 760 mmHg barometric pressure.
P0705 TR SWITCH A/T control is performed in priority order of L, 2, N, D, R and P.
P0720OUTPUT SPEED
SENSOR CIRCUIT
MALFUNCTIONA/T control is performed by using signal from VSS.
P0753SHIFT SOLENOID
A (#1)• A/T control using 3rd gear is performed when D range, 1st, or 2nd 
gear is used.
• TCC solenoid OFF
P0758SHIFT SOLENOID
B (#2)• A/T control using 4th gear is performed when D range, 2nd or 3rd 
gear is used.
• When both shift solenoids A (#1) and B (#2) failed simultaneously, 
A/T control using 4th gear is always performed in D range.
• TCC solenoid OFF
P0743TCC (Lock-up) 
SOLENOIDTCC (Lock-up) solenoid OFF