Downloaded from www.Manualslib.com manuals search engine 6-10 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Precaution in Diagnosing Trouble
Don’t disconnect couplers from ECM, battery cable at battery, ECM ground wire harness from engine or
main fuse before confirming diagnostic information (DTC, freeze frame data, etc.) stored in ECM memory.
Such disconnection will erase memorized information in ECM memory.
Diagnostic information stored in ECM 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 with Immobilizer indicator lamp).
If multiple diagnostic trouble codes (DTCs) are stored, proceed to the flow table of the DTC which has
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 (Fuel system too lean / too rich), DTC
P0300/P0301/P0302/P0303/P0304 (Misfire detected) and DTC P0400 (EGR flow malfunction)
–DTC P0171/P0172 (Fuel system too lean / too rich) and DTC P0400 (EGR flow malfunction)
–DTC P0300/P0301/P0302/P0303/P0304 (Misfire detected)
Be sure to read “Precautions for Electrical Circuit Service” in Section 0A before inspection and observe what
is written there.
ECM Replacement
When substituting a known-good ECM, check for following conditions. Neglecting this check may cause
damage to a known-good ECM.
–Resistance value of all relays, actuators is as specified respectively.
–MAP sensor and TP sensor are in good condition and none of power circuits of these sensors is shorted
to ground.AMBIENT TEMPERATURE TIME TO CUT POWER TO
ECM
Over 0 °C (32 °F) 60 sec. or longer
Under 0 °C (32 °F)Not specifiable.
Select a place with higher than
0 °C (32 °F) temperature.
Downloaded from www.Manualslib.com manuals search engine 6-16 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Diagnostic trouble code (DTC) table
DTC
NO.DETECTING ITEM DETECTING CONDITION
(DTC will set when detecting :)MIL
(vehicle
with immo-
bilizer indi-
cator lamp)MIL
(vehicle
without
immobi-
lizer indica-
tor lamp)
P0105
(No.11)Manifold absolute pressure
circuit malfunctionLow pressure-high vacuum-low voltage
(or MAP sensor circuit shorted to ground)
High pressure-low vacuum-high voltage
(or MAP sensor circuit open)1 driving
cycle1 driving
cycle
P0110
(No.18)Intake air temp. circuit mal-
functionIntake air temp. circuit low input
Intake air temp. circuit high input1 driving
cycle1 driving
cycle
P0115
(No.19)Engine coolant temp. cir-
cuit malfunctionEngine coolant temp. circuit low input
Engine coolant temp. circuit high input1 driving
cycle1 driving
cycle
P0120
(No.13)Throttle position circuit mal-
functionThrottle position circuit low input
Throttle position circuit high input1 driving
cycle1 driving
cycle
P0121Throttle position circuit per-
formance problemPoor performance of TP sensor 2 driving
cyclesNot
applicable
P0130
(No.14)HO2S circuit malfunction
(Sensor-1)Min. output voltage of HO2S-higher than
specification
Max. output voltage of HO2S-lower than
specification2 driving
cycles1 driving
cycle
P0133HO2S circuit slow response
(Sensor-1)Response time of HO2S-1 output voltage
between rich and lean is longer than spec-
ification.2 driving
cyclesNot
applicable
P0135
(No.14)HO2S heater circuit mal-
function (Sensor-1)Terminal voltage is lower than specification
at heater OFF or it is higher at heater ON.2 driving
cycles1 driving
cycle
P0136HO2S circuit malfunction
(Sensor-2)HO2S-2 voltage is higher than specifica-
tion2 driving
cyclesNot
applicable
P0141HO2S heater circuit mal-
function (Sensor-2)Terminal voltage is lower than specification
at heater OFF or it is higher at heater ON.
(or heater circuit or short)2 driving
cyclesNot
applicable
P0171 Fuel system too leanShort term fuel trim or total fuel trim (short
and long terms added) is larger than spec-
ification for specified time or longer.
(fuel trim toward rich side is large.)2 driving
cyclesNot
applicable
P0172 Fuel system too richShort term fuel trim or total fuel trim (short
and long term added) is smaller than spec-
ification for specified time or longer.
(fuel trim toward lean side is large.)2 driving
cyclesNot
applicable
P0300
P0301
P0302
P0303
P0304Random misfire detected
Cylinder 1 misfire detected
Cylinder 2 misfire detected
Cylinder 3 misfire detected
Cylinder 4 misfire detectedMisfire of such level as to cause damage
to three way catalystMIL flashing
during mis-
fire detec-
tionNot
applicable
Misfire of such level as to deteriorate emis-
sion but not to cause damage to three way
catalyst2 driving
cyclesNot
applicable
P0325
(No.17)Knock sensor circuit mal-
functionKnock sensor circuit low input
Knock sensor circuit high input1 driving
cycle1 driving
cycle
Downloaded from www.Manualslib.com manuals search engine 6-24 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Engine has no power
Engine overheating Refer to “Overheating” of this table.
Faulty ignition coil Ignition coil assembly in Section 6F.
Faulty knock sensor Knock sensor malfunction in this sec-
tion.
Fuel pressure out of specification Diagnostic Flow Table B-3
Faulty injector Diagnostic Flow Table B-1
Faulty TP sensor, ECT sensor or MAP
sensorTP sensor, ECT sensor or MAP sen-
sor in Section 6E.
Faulty ECM Inspection of ECM and its circuit in
this section.
Malfunctioning EGR valve (if equipped) EGR system in Section 6E.
Maladjusted accelerator cable play Accelerator cable adjustment in Sec-
tion 6E.
Low compression Previously outlined.
Dragging brakes Diagnosis table in Section 5.
Slipping clutch Diagnosis table in Section 7C.
Improper engine idling
or engine fails to idleFaulty ignition coil Ignition coil assembly in Section 6F.
Engine overheating Refer to “Overheating” of this table.
Fuel pressure out of specification Diagnostic Flow Table B-3
Faulty idle air control system Diagnostic Flow Table B-4
Faulty evaporative emission control sys-
temEVAP control system in Section 6E.
Faulty injector Diagnostic Flow Table B-1
Faulty ECT sensor, TP sensor or MAP
sensorECT sensor, TP sensor or MAP sen-
sor in Section 6E.
Malfunctioning PCV system PCV system in Section 6F.
Faulty ECM Inspection of ECM and its circuit in
this section.
Faulty EGR system (if equipped) EGR system in Section 6E.
Low compression Previously outlined.
Engine hesitates
(Momentary lack of
response as the accel-
erator is depressed.
Can occur at all vehicle
speeds.
Usually most severe
when first trying to
make the vehicle move,
as from a stop sign.)Faulty ignition coil Ignition coil assembly in Section 6F.
Engine overheating Refer to “Overheating” of this table.
Fuel pressure out of specification Diagnostic Flow Table B-3
Faulty injector Diagnostic Flow Table B-1
Faulty TP sensor, ECT sensor or MAP
sensorTP sensor, ECT sensor or MAP sen-
sor in Section 6E.
Faulty ECM Inspection of ECM and its circuit in
this section.
Malfunctioning EGR valve (if equipped) EGR system in Section 6E.
Low compression Previously outlined.
Surges
(Engine power variation
under steady throttle or
cruise.
Feels like the vehicle
speeds up and down
with no change in the
accelerator pedal.)Faulty ignition coil or high-tension cord Ignition coil assembly or high-tension
cords in Section 6F.
Variable fuel pressure Diagnostic Flow Table B-3
Faulty MAP sensor MAP sensor in Section 6E.
Faulty injector Diagnostic Flow Table B-1
Faulty ECM Inspection of ECM and its circuit in
this section.
Malfunctioning EGR valve (if equipped) EGR system in Section 6E. Condition Possible Cause Reference Item
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-61
DTC P0133 Heated Oxygen Sensor (HO2S) Circuit Slow Response (Sensor-1)
WIRING DIAGRAM
Refer to DTC P0130 section.
CIRCUIT DESCRIPTION
Fig. 1
DTC CONFIRMATION PROCEDURE
Refer to DTC P0130 section.
INSPECTION
DTC DETECTING CONDITION POSSIBLE CAUSE
When running at specified idle speed after engine warmed up and
running at specified vehicle speed, response time (time to change
from lean to rich or from rich to lean) of HO2S-1 output voltage is
about 1 sec. at minimum or average time of 1 cycle is 5 sec. at
minimum. See. Fig. 1
✱
✱✱ ✱2 driving cycle detection logic, Monitoring once / 1 driving.Heated oxygen sensor-1 malfunction
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Is there DTC(s) other than HO2S-1 (DTC
P0133)?Go to applicable DTC
Diag. Flow Table.Replace HO2S-1.
Downloaded from www.Manualslib.com manuals search engine 6-80 ENGINE GENERAL INFORMATION AND DIAGNOSIS
INSPECTION
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag.
Flow Table”.
2 Check CKP Sensor and connector for proper
installation.
Is CKP sensor installed properly and connector
connected securely?Go to Step 3. Correct.
3 Check Wire Harness and Connection.
1) Disconnect connector from CKP sensor.
2) Check for proper connection to CKP sensor at
each terminal.
3) If OK, turn ignition switch ON and check for
voltage at each terminal of sensor connector
disconnected. See Fig. 1.
Terminal “B+” : 10 – 14 V
Terminal “Vout” : 4 – 5 V
Terminal “GND” : 0 V
Is check result satisfactory?Go to Step 5. Go to Step 4.
4 Was terminal “Vout” voltage out of specification in
Step 3 check?“G/R” wire open, short or
poor connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.“Bl/B” or “B/R” wire
open, short or poor
connection.
5 Check Ground Circuit for Open.
1) Turn ignition switch OFF.
2) Check for continuity between “GND” terminal
of CKP sensor connector and engine ground.
Is continuity indicated?Go to Step 6.“B/R” wire open or
poor ground connec-
tion.
6 Check CKP Sensor for Operation.
1) Remove CKP sensor from sensor case.
2) Remove metal particles on end face of CKP
sensor, if any.
3) Connect each connector to ECM and CKP
sensor.
4) Turn ignition switch ON.
5) Check for voltage at terminal E19-23 of con-
nector connected to ECM by passing magnetic
substance (iron) (1) while keeping approxi-
mately 1 mm (0.03 in.) gap with respect to end
face of CKP sensor. See Fig. 2 and 3.
Does voltage vary from low (0 – 1 V) to high (4 – 5
V) or from high to low?Go to Step 7. Replace CKP sensor.
7 Check signal rotor for the following. See Fig. 4.
Damage
No foreign material attached
Is it in good condition?Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Clean rotor teeth or
replace CKP sensor.
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-83
INSPECTION
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag.
Flow Table”.
2 Check CMP Sensor and connector for proper installa-
tion.
Is CMP sensor installed properly and connector con-
nected securely?Go to Step 3. Correct.
3 Check Wire Harness and Connection.
1) Disconnect connector from CMP sensor.
2) Check for proper connection to CMP sensor at
each terminal.
3) If OK, turn ignition switch ON and check for volt-
age at each terminal of sensor connector discon-
nected. See Fig. 1.
Terminal “B+” : 10 – 14 V
Terminal “Vout” : 4 – 5 V
Terminal “GND” : 0 V
Is check result satisfactory?Go to Step 5. Go to Step 4.
4 Was terminal “Vout” voltage out of specification in
Step 3 check?“W” wire open, short or
poor connection.
If wire and connection
are OK, substitute a
known-good ECM and
recheck.“Bl/B” or “B/R” wire
open, short or poor
connection.
5 Check Ground Circuit for Open.
1) Turn ignition switch OFF.
2) Check for continuity between “GND” terminal of
CMP sensor connector and engine ground.
Is continuity indicated?Go to Step 6.“B/R” wire open or
poor ground connec-
tion.
6 Check CMP Sensor for Operation.
1) Remove CMP sensor from sensor case.
2) Remove metal particles on end face of CMP sen-
sor, if any.
3) Connect each connector to ECM and CMP sensor.
4) Turn ignition switch ON.
5) Check for voltage at terminal E19-11 of connector
connected to ECM by passing magnetic sub-
stance (iron) (1) while keeping approximately 1
mm (0.03 in.) gap with respect to end face of CMP
sensor. See Fig. 2 and 3.
Does voltage vary from low (0 – 1 V) to high (4 – 5 V)
or from high to low?Go to Step 7. Replace CMP sen-
sor.
7 Check signal rotor for the following.
See Fig. 4.
Damage
No foreign material attached
Is it in good condition?Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Clean rotor teeth or
replace CMP sensor.
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-105
DTC P1600 Serial Communication Problem Between ECM and TCM
CIRCUIT DESCRIPTION
The serial data line is pulled up to about 12 V by ECM and TCM transmits information to ECM through it by con-
trolling its grounding.
TCM constantly sends information while ignition switch is ON as to whether judgement was made or not with
respect to all detectable DTCs as well as whether or not abnormality exists after judgement.
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Start engine and run it at idle for 1 min.
4) Select “DTC” mode on scan tool and check DTC.
INSPECTION
DTC DETECTING CONDITION POSSIBLE CAUSE
No signal inputted from TCM to ECM or check sum
error while engine running“G/R” circuit open or short
TCM power or ground circuit open.
TCM malfunction
ECM malfunction
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Check signal voltage.
Check voltage between terminal E17-17 and
body ground with ignition switch ON. See Fig. 1.
Does it change between 0 – 12 V?Intermittent trouble or
faulty ECM or TCM.
Check for intermittent
trouble referring to “Inter-
mittent and Poor Connec-
tion” in Section 0A.Go to Step 3.
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-109
[D] Table 1 for Step 3 and 4
Table B-1 Fuel Injector Circuit Check
INSPECTION
Scan tool voltmeter
SUZUKI SCAN TOOL
DISPLAYVOLTAGE AT E17-6
Selector lever
position“P” and “N” range P/N range 10 – 14V
“R”, “D”, “2” and “L” range D range 0 – 1V
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Check Injector for Operating Sound.
Using sound scope, check each injector for
operating sound at engine cranking.
Do all 4 injector make operating sound?Fuel injector circuit is in
good condition.Go to Step 3.
3 Dose none of 4 injectors make operating sound
at Step 2?Go to Step 4. Check coupler connec-
tion and wire harness of
injector not making oper-
ating sound and injector
itself (Refer to Section
6E).
4 Check power circuit of injectors for open and
short.
Is it normal?Check all 4 injectors for
resistance respectively.
If resistance is OK, substi-
tute a known-good ECM
and recheck.Power circuit open or
short.