ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-15
MALFUNCTION INDICATOR LAMP (MIL) CHECK
1) Turn ON ignition switch (but the engine at stop) and check
that MIL lights.
If MIL does not light up (or MIL dims), go to “Diagnostic Flow
Table A-1” for troubleshooting.
If MIL flushes, go to “Diagnostic Flow Table A-3” (vehicle
without immobilizer indicator lamp).
2) Start engine and check that MIL turns OFF.
If MIL remains ON and no DTC is stored in ECM, go to
“Diagnostic Flow Table A-2” for troubleshooting.
DIAGNOSTIC TROUBLE CODE (DTC) CHECK
[Using SUZUKI Scan Tool]
1) Prepare SUZUKI scan tool (Tech-1).
2) With ignition switch OFF, connect it to data link connector
(DLC) (1) located on underside of instrument panel at
driver’s seat side.
Special tool
(A) : SUZUKI scan tool
(B) : Mass storage cartridge
(C) : 16/14 pin DLC cable
3) Turn ignition switch ON and confirm that MIL lights.
4) Read DTC, pending DTC and freeze frame data according to
instructions displayed on scan tool and print it or write it
down.
Refer to scan tool operator’s manual for further details.
If communication between scan tool and ECM is not possi-
ble, check if scan tool is communicable by connecting it to
ECM in another vehicle. If communication is possible in this
case, scan tool is in good condition. Then check data link
connector and serial data line (circuit) in the vehicle with
which communication was not possible.
5) After completing the check, turn ignition switch off and dis-
connect scan tool from data link connector.
ODO TRIP AB
1
(A)
(B) (C)
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-33
SCAN TOOL DATA DEFINITIONS :
FUEL SYSTEM (FUEL SYSTEM STATUS)
Air/fuel ratio feedback loop status displayed as either open or closed loop. Open indicates that ECM ignores
feedback from the exhaust oxygen sensor.
Closed indicates final injection duration is corrected for oxygen sensor feedback.
CALC LOAD (CALCULATED LOAD VALUE, %)
Engine load displayed as a percentage of maximum possible load. Value is calculated mathematically using the
formula : actual (current) intake air volume ÷ maximum possible intake air volume x 100%.
COOLANT TEMP. (ENGINE COOLANT TEMPERATURE, °C, °F)
It is detected by engine coolant temp. sensor
SHORT FT B1 (SHORT TERM FUEL TRIM, %)
Short term fuel trim value represents short term corrections to the air/fuel mixture computation. A value of 0 indi-
cates no correction, a value greater than 0 means an enrichment correction, and a value less than 0 implies an
enleanment correction.
LONG FT B1 (LONG TERM FUEL TRIM, %)
Long term fuel trim Value represents long term corrections to the air/fuel mixture computation. A value of 0 indi-
cates no correction, a value greater than 0 means an enrichment correction, and a value less than 0 implies an
enleanment correction.
MAP (INTAKE MANIFOLD ABSOLUTE PRESSURE, kPa, inHg)
It is detected by manifold absolute pressure sensor and used (among other things) to compute engine load.
ENGINE SPEED (rpm)
It is computed by reference pulses from crankshaft position sensor.
VEHICLE SPEED (km/h, MPH)
It is computed based on pulse signals from vehicle speed sensor.PNP SIGNAL (PARK/NEU-
TRAL POSITION SIGNAL)
A/T onlyIgnition switch
ONSelector lever in “P” or “N”
positionP/N Range
Selector lever in “R”, “D”,
“2” or “L” positionD Range
EGR VALVE At specified idle speed after warming up 0%
∆FUEL TANK LEVEL–0 – 100%
BAROMETRIC PRESS–Display the barometric pres-
sure
FUEL PUMP Within 3 seconds after ignition switch ON or
engine runningON
Engine stop at ignition switch ON. OFF
BRAKE SW Ignition switch
ONBrake pedal is depressing ON
Brake pedal is releasing OFF
BLOWER FAN Ignition switch
ONBlower fan switch ON ON
Blower fan switch OFF OFF
A/C MAG CLUTCH Ignition switch
ONA/C switch ON ON
A/C switch OFF OFF SCAN TOOL DATA VEHICLE CONDITION NORMAL CONDITION/
REFERENCE VALUES
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-55
DTC P0110 (DTC NO.18) INTAKE AIR TEMP. (IAT) CIRCUIT MALFUNCTION
WIRING DIAGRAM / CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and keep it at idle for 1 min.
2) Select “DTC” mode no scan tool and check DTC.
INSPECTION
C42-10
C42-15
5V
ECM
LT GRN/BLK
ORN
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
DTC DETECTING CONDITION POSSIBLE CAUSE
Low intake air temperature (High voltage-High resistance)
or
High intake air temperature (Low voltage-Low resistance)“LT GRN/BLK” circuit open or shorted to
power.
“ORN” circuit open
IAT sensor malfunction
ECM malfunction
NOTE:
When DTC P0105 (No.11), P0110 (No.18), P0115 (No.19) and P0120 (No.13) are indicated together, it
is possible that “ORN” circuit is open.
Before inspecting, be sure to check that ambient temperature is higher than – 40°C (– 40°F).
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check IAT Sensor and Its Circuit.
1) Connect scan tool to DLC with ignition
switch OFF.
2) Turn ignition switch ON.
3) Check intake air temp. displayed on scan
tool. See Fig. 1.
Is – 40°C (– 40°F) or 119°C (246°F) indicated?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.
6-56 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Fig. 1 for Step 2
Fig. 2 for Step 33 Check Wire Harness.
1) Disconnect IAT sensor connector with igni-
tion switch OFF.
2) Check for proper connection to IAT sensor
at “LT GRN/BLK” and “ORN” wire terminals.
3) If OK, then with ignition switch ON, is volt-
age applied to “LT GRN/BLK” wire terminal
about 4 – 6 V? See Fig. 2.Go to Step 5.“LT GRN/BLK” wire open
or shorted to power, or
poor C42-15 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.
4 Does scan tool indicate – 40°C (– 40°F) at Step
2.Go to Step 6. Go to Step 5.
5 Check Wire Harness
1) Check intake air temp. displayed on scan
tool with ignition switch ON.
Is – 40°C (– 40°F) indicated?Replace IAT sensor.“LT GRN/BLK” wire
shorted to ground.
If wire is OK, substitute a
known-good ECM and
recheck.
6 Check Wire Harness.
1) Using service wire, connect IAT sensor con-
nector terminals.
2) Check intake air temp. displayed on scan
tool with ignition switch ON. See Fig. 3.
Is 119°C (246°F) indicated?Replace IAT sensor.“LT GRN/BLK” wire open
or poor C42-10 connec-
tion.
If wire and connection are
OK, substitute a known-
good ECM and recheck. Step Action Yes No
6-58 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and keep it at idle for 1 min.
2) Select “DTC” mode no scan tool and check DTC.
INSPECTION
Fig. 1 for Step 2Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
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. See Fig. 1.
Is – 40°C (– 40°F) or 119°C (246°F) indicated?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0 A.
3 Check Wire Harness.
1) Disconnect ECT sensor connector.
2) Check engine coolant temp. displayed on
scan tool.
Is – 40°C (– 40°F) indicated?Replace ECT sensor.“LT GRN” wire shorted to
ground.
If wire is OK, substitute a
known-good ECM and
recheck.
4 Does scan tool indicate – 40°C (– 40°F) at Step
2.Go to Step 6. Go to Step 5.
5 Check Wire Harness.
1) Disconnect ECT sensor connector with igni-
tion switch OFF.
2) Check for proper connection to ECT sensor
at “ORN” and “LT GRN” wire terminals.
If OK, then with ignition switch ON, is voltage
applied to “LT GRN” wire terminal about 4 – 6
V? See Fig. 2.Go to Step 4.“LT GRN” wire open or
shorted to power, or poor
C42-14 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.
6 Check Wire Harness.
1) Using service wire, connect ECT sensor
connector terminals. See Fig. 3.
2) Turn ignition switch ON and check engine
coolant temp. displayed on scan tool.
Is 119°C (246°F) indicated?Replace ECT sensor.“ORN” wire open or poor
C42-10 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-61
INSPECTION
Fig. 1 for Step 2Step Action Yes No
1Was “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. See Fig. 1.
Is it displayed 2% or less?
3) Check throttle valve opening percentage
displayed on scan tool while opening throt-
tle valve from idle position to full open posi-
tion. See Fig. 1.
Is it displayed 96% or higher?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0 A.
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”, “GRY/BLU” and “ORN” wire
terminals.
3) If OK, then with ignition switch ON, check
voltage between each of “GRY/RED” or
“GRY/BLU” wire terminals and body
ground. See Fig. 2.
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 “GRY/BLU” wire,
“ORN” wire open or
shorted to ground circuit
or poor C42-22 or C41-3
(For TYPE A, See NOTE)
or C42-16 (For TYPE B,
See NOTE) 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. See Fig. 3.
Between 1 and 2 : 2.5 – 6.0 kΩ
Between 1 and 3 : 100 Ω – 20 kΩ
varying according to throttle valve opening
Are measured values within specifications?“ORN” wire open or poor
C42-10 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.Replace TP sensor.
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-73
6) Repeat above steps 5) 4 times.
7) Increase vehicle speed to about 50 mph (80 km/h) in 3rd gear or 2 range.
8) Release accelerator pedal and with engine brake applied, keep vehicle coasting (fuel cut condition) for
10sec. or more.
9) Stop vehicle (don’t turn ignition switch OFF) and run engine at idle for 2 min.
After this step 9), if “Oxygen Sensor Monitoring TEST COMPLETED” is displayed in “READINESS TESTS”
mode and DTC is not displayed in “DTC” mode, confirmation test is completed.
If “TEST NOT COMPLTD” is still being displayed, proceed to next step 10).
10) Drive vehicle under usual driving condition for 10 min. (or vehicle is at a stop and run engine at idle for 10
min. or longer)
11) Stop vehicle (don’t turn ignition switch OFF). Confirm test results according to “Test Result Confirmation
Flow Table” in “DTC CONFIRMATION PROCEDURE” of DTC P0420.
INSPECTION
Usual driving : Driving at 30 – 40 mph, 50 – 60 km/h including short stop according to traffic signal. (under driving condition other than high-load, high-engine
speed, rapid accelerating and decelerating)
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check Exhaust System for leakage, loose con-
nection and damage.
Is it good condition?Go to Step 3. Repair or replace.
3 Check HO2S-2 and Its Circuit.
Was HO2S-2 output voltage indicated on scan
tool in step 3) of DTC confirmation test less
than 1.275 V?Go to Step 4.“BRN”, “YEL” or “ORN”
circuit short to power sup-
ply circuit or HO2S-2 mal-
function.
4 Check Short Term Fuel Trim.
Did short term fuel trim very within – 20 – + 20%
range in step 3) of DTC confirmation test?Check “BRN”, “YEL” or
“ORN” wire for open and
short, and connection for
poor connection. If wire
and connection are OK,
replace HO2S-2.Check fuel system. Go to
DTC P0171/P0172 Diag.
Flow Table.
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-95
7) Stop vehicle (don't turn ignition switch OFF) and confirm test results according to following “Test Result Con-
firmation Flow Table”.
TEST RESULT CONFIRMATION FLOW TABLE
INSPECTION
Step Action Yes No
1Check DTC in “DTC” mode and pending DTC in
“ON BOARD TEST”.
Is DTC or pending DTC displayed?Proceed to applicable
DTC flow table.Go to Step 2.
2 Set scan tool to “READINESS TESTS” mode
and check if testing has been completed.
Is test completed?No DTC is detected.
(Confirmation test is com-
pleted)Repeat DTC confirmation
procedure.
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Do you have SUZUKI scan tool? Go to Step 4. Go to Step 5.
3 EGR Valve Operation Check :
1) With ignition switch OFF, install SUZUKI
scan tool.
2) Check EGR system referring to Section
6E1.
Is it in good condition?Go to Step 4. Go to Step 5.
4 MAP Sensor Check :
1) Check MAP sensor for performance refer-
ring to Section 6E1.
Is check result satisfactory?Intermittent trouble or
faulty ECM. Check for
intermittent referring to
“Intermittent and Poor
Connection” in Section
0A.Repair or replace.